C# | PAPER

(1) Full Form: IDE.
--> Integrated Development Environment. It is a software application that provides comprehensive facilities to computer programmers for software development, typically combining a code editor, compiler, and debugger.

---

(2) Explain: Managed Code.
--> Managed Code is code whose execution is managed by the Common Language Runtime (CLR) in the .NET Framework. The CLR handles automatic tasks for it, such as memory management (garbage collection), exception handling, and type safety.

---

(3) Explain: Unmanaged Code.
--> Unmanaged Code is code that is executed directly by the operating system, outside the control of the .NET CLR. The programmer is fully responsible for manual memory management, security, and handling leaks (e.g., traditional C/C++ code).

(1) Explain: JIT and Types.
--> The JIT (Just-In-Time) Compiler is a component of the CLR that converts Microsoft Intermediate Language (MSIL) into native machine code just before it is executed.
Types of JIT:
1. Normal-JIT: Compiles methods only when they are called at runtime and caches them in memory for future calls.
2. Econo-JIT: Compiles methods at runtime but removes them from memory when no longer required to save space (mostly obsolete).
3. Pre-JIT: Compiles the entire application code into native code at the time of installation (using the NGEN tool).

---

(2) Describe Namespaces.
--> A Namespace is a logical container used to organize code and prevent naming collisions. It allows you to group related classes, interfaces, enums, and structs together (e.g., System.IO for input/output). If two classes share the same name but exist in different namespaces, the compiler can distinguish between them.

---

(1) List All and Describe any one Looping Structure.
--> * EXPLANATION:

List of Looping Structures in C#/.NET:
1. for loop
2. while loop
3. do-while loop
4. foreach loop

 * EXPLANATION & EXAMPLE of 'for' loop:
   The for loop is an entry-controlled loop used when the number of iterations is known in advance. It contains initialization, condition, and increment/decrement all in a single line.
   
   using System;
   
   class Program {
       static void Main() {
           // Loop prints numbers from 1 to 5
           for(int i = 1; i <= 5; i++) {
               Console.WriteLine("Number: " + i);
           }
       }
   }

---

(2) Explain .Net Framework with Advantages and Disadvantages.
--> * EXPLANATION:

- The .NET Framework is a software development platform created by Microsoft for building and running applications.
- Its two core components are the Common Language Runtime (CLR) (the execution engine) and the Framework Class Library (FCL) (a massive collection of reusable classes).

Advantages:
1. Language Interoperability: Code written in one language (like C#) can easily interact with code in another (like VB.NET).
2. Automatic Memory Management: The Garbage Collector automatically reclaims memory, reducing memory leaks.
3. Rich Class Library: Thousands of built-in classes speed up development for UI, database, and network tasks.

Disadvantages:
1. Platform Limitation: The original .NET Framework is restricted to Windows OS (though modern .NET Core solves this).
2. Performance Overhead: JIT compilation and Garbage Collection can introduce slight runtime delays compared to raw unmanaged C++ code.

---

---

(1) What is Static Member?
--> A Static Member is a class member (variable, method, etc.) that belongs to the class itself rather than to any specific object instance. There is only one copy of a static member in memory, which is shared by all instances of the class. It is accessed using the class name directly (e.g., Math.PI).

---

(2) What is Non-Static Member?
--> A Non-Static Member (also called an Instance Member) belongs to a specific instance (object) of a class. Every time you create a new object, a new copy of all non-static variables is created. These members must be accessed through an object reference.

---

(3) Explain: Sealed Class.
--> A Sealed Class is a class that cannot be inherited by any other class. It is created using the sealed keyword. This is often used to restrict the object-oriented inheritance hierarchy for security reasons, or to prevent unintended modification of a class's behavior.

(1) Explain: Interface Inheritance.
--> Interface Inheritance occurs when one interface inherits from one or more other interfaces. The derived interface inherits all the abstract members of the parent interface(s). When a class implements the derived interface, it is required to provide concrete implementations for all methods defined in both the derived and the parent interfaces.

---

(2) Explain Encapsulation in Detail.
--> Encapsulation is one of the fundamental pillars of Object-Oriented Programming (OOP).
- It is the process of wrapping data (variables) and code acting on the data (methods) together into a single unit, usually a Class.
- It also enables Data Hiding. By declaring class variables as private, they cannot be accessed directly from outside the class.
- Access to these private fields is provided via public methods or Properties (getters and setters), allowing the class to control how its data is modified or retrieved, ensuring data integrity.

---

(1) Explain: Creating and using Pointers with Example.
--> * EXPLANATION:

- In C#, pointers are used to store the memory address of another type. They bypass the standard memory management (Garbage Collection).
- Because manipulating memory directly can be dangerous, C# requires you to write pointer code inside an unsafe block or method.
- You must also enable the "Allow unsafe code" option in your project compiler settings.
- Operators used: * (to declare a pointer and dereference it to get the value) and & (to get the memory address of a variable).

 * EXPLANATION & EXAMPLE:
   
   using System;
   
   class Program {
       // Marking the method as unsafe to allow pointer usage
       static unsafe void Main() {
           int number = 50;
           
           // Create a pointer 'ptr' and assign it the address of 'number'
           int* ptr = &number; 
           
           Console.WriteLine("Value of number: " + number);
           // Display memory address (cast to int for displaying)
           Console.WriteLine("Memory Address: " + (int)ptr); 
           
           // Dereferencing the pointer to change the value at that address
           *ptr = 100; 
           
           Console.WriteLine("New Value of number: " + number); 
           // Output will be 100 because the memory was directly modified
       }
   }

---

(2) Explain: Constructor with Overloading.
--> * EXPLANATION:

- A Constructor is a special method whose name is the same as the class name, used to initialize an object.
- Constructor Overloading is a technique in which a class can have multiple constructors with the same name, but with a different number, type, or order of parameters.
- It allows the user to initialize an object in different ways depending on the data they have available at the time of creation.

 * EXPLANATION & EXAMPLE:
   
   using System;
   
   class Product {
       public string Name;
       public double Price;
       
       // 1st Constructor: Default (No parameters)
       public Product() {
           Name = "Unknown";
           Price = 0.0;
       }
       
       // 2nd Constructor: Overloaded (One parameter)
       public Product(string name) {
           Name = name;
           Price = 10.0; // Default price
       }
       
       // 3rd Constructor: Overloaded (Two parameters)
       public Product(string name, double price) {
           Name = name;
           Price = price;
       }
       
       public void Display() {
           Console.WriteLine($"Product: {Name}, Price: {Price}");
       }
   }
   
   class Program {
       static void Main() {
           // Invokes 1st constructor
           Product p1 = new Product();         
           
           // Invokes 2nd constructor
           Product p2 = new Product("Pen");    
           
           // Invokes 3rd constructor
           Product p3 = new Product("Book", 50.5); 
           
           p1.Display();
           p2.Display();
           p3.Display();
       }
   }

---

(1) Describe: ComboBox.
--> A ComboBox is a Windows Forms control that combines the features of a TextBox and a ListBox. It displays a drop-down list of items from which the user can select one, and depending on its style, it may also allow the user to type in a custom value.

---

(2) Describe: ListBox.
--> A ListBox is a Windows Forms control used to display a vertical list of items. Unlike a ComboBox, the list is generally always visible (or scrollable). It can be configured to allow the user to select a single item or multiple items simultaneously.

---

(3) Describe: ScrollBar.
--> A ScrollBar control (available as HScrollBar for horizontal and VScrollBar for vertical) allows users to scroll through content, large images, or data that extends beyond the visible viewing area of a container. It uses a sliding thumb box to indicate position.

(1) Explain: MenuStrip & ContextMenuStrip.
--> MenuStrip: It is the standard control used to create a top-level menu system for a Windows Form (e.g., File, Edit, View, Help). It sits at the top of the form and provides access to application commands.
--> ContextMenuStrip: It is used to create shortcut menus (pop-up menus) that appear only when the user right-clicks on a specific control or the form itself. It provides context-specific options.

---

(2) Write Steps to Create Windows Application.
--> To create a standard Windows Forms Application in Visual Studio:
1. Open Visual Studio.
2. Click on Create a new project.
3. Search for and select Windows Forms App (.NET Framework) for C# or VB.NET, then click Next.
4. Enter a Project Name and choose a location to save it, then click Create.
5. A blank Form (Form1) will appear in the designer. You can now drag and drop controls from the Toolbox onto the form and double-click them to write code.

---

(1) List and Explain All DialogBoxes.
--> * EXPLANATION:

Dialog Boxes are standard pre-built forms provided by Windows to perform common tasks, ensuring a consistent user experience. The main standard dialog boxes in .NET are:

1. OpenFileDialog: Prompts the user to browse their computer and select one or more existing files to open.
2. SaveFileDialog: Prompts the user to select a location and specify a file name to save a file.
3. FontDialog: Allows the user to select a font face, style (bold/italic), size, and color for text.
4. ColorDialog: Displays a color palette allowing the user to pick a standard color or define a custom color.
5. FolderBrowserDialog: Prompts the user to browse and select a directory/folder rather than a specific file.
(Note: These dialogs do not perform the actual opening/saving/coloring themselves; they just return the user's selection to your code.)

---

(2) List and explain any 3 Events with Example.
--> * EXPLANATION:

An Event is an action or occurrence (like a mouse click or key press) that the application can detect and respond to by executing a block of code (an Event Handler).

1. Click Event: Triggered when the user clicks on a control (most commonly used with Buttons).
2. TextChanged Event: Triggered whenever the text inside a control (like a TextBox) changes.
3. Load Event: Triggered when a Form is loaded into memory before it is displayed on the screen. Good for initialization.

 * EXPLANATION & EXAMPLE (C#):
   
   using System;
   using System.Windows.Forms;
   
   public partial class Form1 : Form {
       
       public Form1() {
           InitializeComponent();
       }
       
       // 1. Load Event Example
       private void Form1_Load(object sender, EventArgs e) {
           // Sets default text when form opens
           textBox1.Text = "Welcome"; 
       }
       
       // 2. Click Event Example
       private void button1_Click(object sender, EventArgs e) {
           // Shows a message when button is clicked
           MessageBox.Show("Button was clicked!"); 
       }
       
       // 3. TextChanged Event Example
       private void textBox1_TextChanged(object sender, EventArgs e) {
           // Copies text from textBox1 to label1 as the user types
           label1.Text = textBox1.Text; 
       }
   }

---

---

(1) Explain: DataRow.
--> A DataRow object represents a single row (record) of data within a DataTable in ADO.NET. It contains the actual data values corresponding to the columns defined in the table. You use it to add, extract, or update data in a disconnected architecture.

---

(2) Explain: DataColumn.
--> A DataColumn object represents the schema or structure of a single column within a DataTable. It defines the name of the column, its data type (e.g., integer, string), and rules or constraints (such as whether it allows null values, is read-only, or is unique).

---

(3) Explain: DataRelation.
--> A DataRelation represents a parent-child relationship between two DataTable objects within a DataSet. It acts similarly to a Foreign Key in a relational database, allowing you to navigate from a parent record to its related child records directly in memory.

(1) Explain Data Providers in ADO.Net.
--> .NET Data Providers are sets of components designed for data manipulation and fast, forward-only, read-only access to data. They act as a bridge between your application and the database.
Core objects included in a provider are:
1. Connection: Establishes a connection to a specific data source.
2. Command: Executes queries or stored procedures.
3. DataReader: Reads a forward-only stream of data from the database.
4. DataAdapter: Populates a disconnected DataSet and resolves updates with the database.
(Examples: System.Data.SqlClient for SQL Server, System.Data.OleDb for Access/Excel).

---

(2) Explain Connection object With Example.
--> The Connection Object is used to establish a physical connection to a specific data source (like a SQL Server database). It requires a connection string that contains information like the server name, database name, and authentication details. You must open the connection before performing operations and close it immediately after.

 * EXPLANATION & EXAMPLE:
   
   using System.Data.SqlClient;
   
   // Create connection string
   string conString = "Data Source=ServerName;Initial Catalog=DbName;Integrated Security=True";
   
   // Instantiate Connection object
   SqlConnection con = new SqlConnection(conString);
   
   try {
       con.Open(); // Open the connection
       // Perform database operations here...
   } finally {
       con.Close(); // Always close to release resources
   }

---

(1) Write Code to Insert Records using Disconnected Architecture.
--> * EXPLANATION:

In a Disconnected Architecture, we use a DataSet, SqlDataAdapter, and SqlCommandBuilder. The application downloads a copy of the data into memory (DataSet), adds a new DataRow, and then the DataAdapter pushes the changes back to the database.

 * CODE EXAMPLE:
   
   using System;
   using System.Data;
   using System.Data.SqlClient;
   
   class Program {
       static void Main() {
           string conStr = "Data Source=ServerName;Initial Catalog=DbName;Integrated Security=True";
           string query = "SELECT * FROM Employees";
           
           using (SqlConnection con = new SqlConnection(conStr)) {
               // 1. Create DataAdapter
               SqlDataAdapter da = new SqlDataAdapter(query, con);
               
               // 2. Automatically generate Insert/Update/Delete commands
               SqlCommandBuilder builder = new SqlCommandBuilder(da);
               
               // 3. Create and fill the DataSet
               DataSet ds = new DataSet();
               da.Fill(ds, "Employees");
               
               // 4. Create a new DataRow matching the table structure
               DataTable dt = ds.Tables["Employees"];
               DataRow newRow = dt.NewRow();
               newRow["EmpName"] = "John Doe";
               newRow["Salary"] = 50000;
               
               // 5. Add row to the disconnected DataTable
               dt.Rows.Add(newRow);
               
               // 6. Update the physical database with the new changes
               da.Update(ds, "Employees");
               
               Console.WriteLine("Record inserted successfully!");
           }
       }
   }

---

(2) Write Code to Delete Records using Connected Architecture.
--> * EXPLANATION:

In a Connected Architecture, we use the SqlConnection and SqlCommand objects. The connection is explicitly opened, a DELETE query is executed directly against the database using ExecuteNonQuery(), and the connection is closed immediately.

 * CODE EXAMPLE:
   
   using System;
   using System.Data.SqlClient;
   
   class Program {
       static void Main() {
           string conStr = "Data Source=ServerName;Initial Catalog=DbName;Integrated Security=True";
           
           // The DELETE query with a parameter to prevent SQL Injection
           string query = "DELETE FROM Employees WHERE EmpId = @Id";
           
           using (SqlConnection con = new SqlConnection(conStr)) {
               // 1. Create the Command object
               using (SqlCommand cmd = new SqlCommand(query, con)) {
                   
                   // 2. Supply the parameter value
                   cmd.Parameters.AddWithValue("@Id", 101); // Deletes employee with ID 101
                   
                   // 3. Open connection, execute, and close
                   con.Open();
                   int rowsAffected = cmd.ExecuteNonQuery();
                   con.Close();
                   
                   if (rowsAffected > 0)
                       Console.WriteLine("Record deleted successfully!");
                   else
                       Console.WriteLine("No record found with that ID.");
               }
           }
       }
   }

---

---

(1) What is File System Editor?
--> The File System Editor is a deployment tool in Visual Studio used to manage and map the folder structure of the target machine. It allows developers to specify exactly where the application's files (like .exe, .dll, and resource files) should be placed when the application is installed on a user's computer.

---

(2) What is User Interface Editor?
--> The User Interface Editor is used to customize the series of dialog boxes that the end-user sees during the installation process. Developers can add, remove, or reorder screens such as the Welcome screen, License Agreement, Installation Folder selection, and the Finished dialog.

---

(3) What is Launch Condition Editor?
--> The Launch Condition Editor is used to define prerequisites that must be met on the target machine before the installation can proceed. For example, it can check if a specific version of the .NET Framework, a certain operating system, or a required database component is installed, and abort the setup if conditions are not met.

(1) Explain Types of Reports.
--> In reporting tools (like Crystal Reports or SSRS), data can be presented in several formats. Common types include:
1. Tabular Reports: The most basic format, displaying data in simple rows and columns (like a spreadsheet).
2. Matrix/Cross-Tab Reports: Displays grouped data in a grid format, summarizing data at the intersections of rows and columns (similar to a pivot table).
3. Chart Reports: Represents data graphically using bar charts, pie charts, line graphs, etc., for quick visual analysis.
4. Drill-Down Reports: Interactive reports that allow users to click on summary data to reveal the detailed, hidden data underneath.

---

(2) Explain Setup Project.
--> A Setup Project in Visual Studio is a special type of project used to create an installer package (usually a .msi or setup.exe file) for a completed application. It bundles the compiled code, dependencies, registry keys, and necessary resources into a single distributable file, making it easy to deploy and install the software safely on end-user machines.

---

(1) Write a Program to Create and use User Control.
--> * EXPLANATION:

A User Control is a custom, reusable GUI component created by grouping together one or more existing standard Windows Forms controls. This is useful when you need the same combination of controls (like a Label paired with a TextBox) in multiple places.

 * EXPLANATION & EXAMPLE:
   
   // Part 1: Creating the User Control (Named "MyUserControl")
   // Assume you added a UserControl to your project and dragged 
   // a Label and a TextBox onto it.
   using System.Windows.Forms;
   
   public partial class MyUserControl : UserControl {
       public MyUserControl() {
           InitializeComponent(); 
       }
       
       // Creating a property to easily get/set the TextBox text
       public string InputText {
           get { return textBox1.Text; }
           set { textBox1.Text = value; }
       }
   }
   
   // Part 2: Using the User Control in a Windows Form
   using System.Drawing;
   using System.Windows.Forms;
   
   public partial class Form1 : Form {
       public Form1() {
           InitializeComponent();
           
           // Instantiate the custom User Control
           MyUserControl customControl = new MyUserControl();
           
           // Set its properties
           customControl.Location = new Point(20, 20);
           customControl.InputText = "Hello User!";
           
           // Add it to the Form's Controls collection
           this.Controls.Add(customControl);
       }
   }

---

(2) List out and Explain Types of Setup Projects.
--> * EXPLANATION:

Visual Studio provides several types of deployment projects to handle different application scenarios. The main types include:

1. Setup Project: Used to create a standard Windows Installer (.msi) for deploying desktop applications (like Windows Forms or WPF apps) to client machines.

2. Web Setup Project: Used specifically to deploy web applications, web services, and web content to an IIS (Internet Information Services) web server.

3. Merge Module Project: Creates a reusable package (.msm file) that contains components, DLLs, or files that are shared across multiple applications. These modules cannot be installed on their own; they must be merged into a standard Setup Project.

4. Setup Wizard: Not a separate project type, but rather a guided, step-by-step wizard that asks you questions about your application and automatically generates the correct type of Setup Project based on your answers.

5. CAB Project: Used to create Cabinet (.cab) files. These are primarily used for packaging components that need to be downloaded from a web browser over the internet (mostly legacy).

---

C# | PAPER

(1) Full Form: IDE.
--> Integrated Development Environment. It is a software application that provides comprehensive facilities to computer programmers for software development, typically combining a code editor, compiler, and debugger.

---

(2) Explain: Managed Code.
--> Managed Code is code whose execution is managed by the Common Language Runtime (CLR) in the .NET Framework. The CLR handles automatic tasks for it, such as memory management (garbage collection), exception handling, and type safety.

---

(3) Explain: Unmanaged Code.
--> Unmanaged Code is code that is executed directly by the operating system, outside the control of the .NET CLR. The programmer is fully responsible for manual memory management, security, and handling leaks (e.g., traditional C/C++ code).

(1) Explain: JIT and Types.
--> The JIT (Just-In-Time) Compiler is a component of the CLR that converts Microsoft Intermediate Language (MSIL) into native machine code just before it is executed.
Types of JIT:
1. Normal-JIT: Compiles methods only when they are called at runtime and caches them in memory for future calls.
2. Econo-JIT: Compiles methods at runtime but removes them from memory when no longer required to save space (mostly obsolete).
3. Pre-JIT: Compiles the entire application code into native code at the time of installation (using the NGEN tool).

---

(2) Describe Namespaces.
--> A Namespace is a logical container used to organize code and prevent naming collisions. It allows you to group related classes, interfaces, enums, and structs together (e.g., System.IO for input/output). If two classes share the same name but exist in different namespaces, the compiler can distinguish between them.

---

(1) List All and Describe any one Looping Structure.
--> * EXPLANATION:

List of Looping Structures in C#/.NET:
1. for loop
2. while loop
3. do-while loop
4. foreach loop

 * EXPLANATION & EXAMPLE of 'for' loop:
   The for loop is an entry-controlled loop used when the number of iterations is known in advance. It contains initialization, condition, and increment/decrement all in a single line.
   
   using System;
   
   class Program {
       static void Main() {
           // Loop prints numbers from 1 to 5
           for(int i = 1; i <= 5; i++) {
               Console.WriteLine("Number: " + i);
           }
       }
   }

---

(2) Explain .Net Framework with Advantages and Disadvantages.
--> * EXPLANATION:

- The .NET Framework is a software development platform created by Microsoft for building and running applications.
- Its two core components are the Common Language Runtime (CLR) (the execution engine) and the Framework Class Library (FCL) (a massive collection of reusable classes).

Advantages:
1. Language Interoperability: Code written in one language (like C#) can easily interact with code in another (like VB.NET).
2. Automatic Memory Management: The Garbage Collector automatically reclaims memory, reducing memory leaks.
3. Rich Class Library: Thousands of built-in classes speed up development for UI, database, and network tasks.

Disadvantages:
1. Platform Limitation: The original .NET Framework is restricted to Windows OS (though modern .NET Core solves this).
2. Performance Overhead: JIT compilation and Garbage Collection can introduce slight runtime delays compared to raw unmanaged C++ code.

---

---

(1) What is Static Member?
--> A Static Member is a class member (variable, method, etc.) that belongs to the class itself rather than to any specific object instance. There is only one copy of a static member in memory, which is shared by all instances of the class. It is accessed using the class name directly (e.g., Math.PI).

---

(2) What is Non-Static Member?
--> A Non-Static Member (also called an Instance Member) belongs to a specific instance (object) of a class. Every time you create a new object, a new copy of all non-static variables is created. These members must be accessed through an object reference.

---

(3) Explain: Sealed Class.
--> A Sealed Class is a class that cannot be inherited by any other class. It is created using the sealed keyword. This is often used to restrict the object-oriented inheritance hierarchy for security reasons, or to prevent unintended modification of a class's behavior.

(1) Explain: Interface Inheritance.
--> Interface Inheritance occurs when one interface inherits from one or more other interfaces. The derived interface inherits all the abstract members of the parent interface(s). When a class implements the derived interface, it is required to provide concrete implementations for all methods defined in both the derived and the parent interfaces.

---

(2) Explain Encapsulation in Detail.
--> Encapsulation is one of the fundamental pillars of Object-Oriented Programming (OOP).
- It is the process of wrapping data (variables) and code acting on the data (methods) together into a single unit, usually a Class.
- It also enables Data Hiding. By declaring class variables as private, they cannot be accessed directly from outside the class.
- Access to these private fields is provided via public methods or Properties (getters and setters), allowing the class to control how its data is modified or retrieved, ensuring data integrity.

---

(1) Explain: Creating and using Pointers with Example.
--> * EXPLANATION:

- In C#, pointers are used to store the memory address of another type. They bypass the standard memory management (Garbage Collection).
- Because manipulating memory directly can be dangerous, C# requires you to write pointer code inside an unsafe block or method.
- You must also enable the "Allow unsafe code" option in your project compiler settings.
- Operators used: * (to declare a pointer and dereference it to get the value) and & (to get the memory address of a variable).

 * EXPLANATION & EXAMPLE:
   
   using System;
   
   class Program {
       // Marking the method as unsafe to allow pointer usage
       static unsafe void Main() {
           int number = 50;
           
           // Create a pointer 'ptr' and assign it the address of 'number'
           int* ptr = &number; 
           
           Console.WriteLine("Value of number: " + number);
           // Display memory address (cast to int for displaying)
           Console.WriteLine("Memory Address: " + (int)ptr); 
           
           // Dereferencing the pointer to change the value at that address
           *ptr = 100; 
           
           Console.WriteLine("New Value of number: " + number); 
           // Output will be 100 because the memory was directly modified
       }
   }

---

(2) Explain: Constructor with Overloading.
--> * EXPLANATION:

- A Constructor is a special method whose name is the same as the class name, used to initialize an object.
- Constructor Overloading is a technique in which a class can have multiple constructors with the same name, but with a different number, type, or order of parameters.
- It allows the user to initialize an object in different ways depending on the data they have available at the time of creation.

 * EXPLANATION & EXAMPLE:
   
   using System;
   
   class Product {
       public string Name;
       public double Price;
       
       // 1st Constructor: Default (No parameters)
       public Product() {
           Name = "Unknown";
           Price = 0.0;
       }
       
       // 2nd Constructor: Overloaded (One parameter)
       public Product(string name) {
           Name = name;
           Price = 10.0; // Default price
       }
       
       // 3rd Constructor: Overloaded (Two parameters)
       public Product(string name, double price) {
           Name = name;
           Price = price;
       }
       
       public void Display() {
           Console.WriteLine($"Product: {Name}, Price: {Price}");
       }
   }
   
   class Program {
       static void Main() {
           // Invokes 1st constructor
           Product p1 = new Product();         
           
           // Invokes 2nd constructor
           Product p2 = new Product("Pen");    
           
           // Invokes 3rd constructor
           Product p3 = new Product("Book", 50.5); 
           
           p1.Display();
           p2.Display();
           p3.Display();
       }
   }

---

(1) Describe: ComboBox.
--> A ComboBox is a Windows Forms control that combines the features of a TextBox and a ListBox. It displays a drop-down list of items from which the user can select one, and depending on its style, it may also allow the user to type in a custom value.

---

(2) Describe: ListBox.
--> A ListBox is a Windows Forms control used to display a vertical list of items. Unlike a ComboBox, the list is generally always visible (or scrollable). It can be configured to allow the user to select a single item or multiple items simultaneously.

---

(3) Describe: ScrollBar.
--> A ScrollBar control (available as HScrollBar for horizontal and VScrollBar for vertical) allows users to scroll through content, large images, or data that extends beyond the visible viewing area of a container. It uses a sliding thumb box to indicate position.

(1) Explain: MenuStrip & ContextMenuStrip.
--> MenuStrip: It is the standard control used to create a top-level menu system for a Windows Form (e.g., File, Edit, View, Help). It sits at the top of the form and provides access to application commands.
--> ContextMenuStrip: It is used to create shortcut menus (pop-up menus) that appear only when the user right-clicks on a specific control or the form itself. It provides context-specific options.

---

(2) Write Steps to Create Windows Application.
--> To create a standard Windows Forms Application in Visual Studio:
1. Open Visual Studio.
2. Click on Create a new project.
3. Search for and select Windows Forms App (.NET Framework) for C# or VB.NET, then click Next.
4. Enter a Project Name and choose a location to save it, then click Create.
5. A blank Form (Form1) will appear in the designer. You can now drag and drop controls from the Toolbox onto the form and double-click them to write code.

---

(1) List and Explain All DialogBoxes.
--> * EXPLANATION:

Dialog Boxes are standard pre-built forms provided by Windows to perform common tasks, ensuring a consistent user experience. The main standard dialog boxes in .NET are:

1. OpenFileDialog: Prompts the user to browse their computer and select one or more existing files to open.
2. SaveFileDialog: Prompts the user to select a location and specify a file name to save a file.
3. FontDialog: Allows the user to select a font face, style (bold/italic), size, and color for text.
4. ColorDialog: Displays a color palette allowing the user to pick a standard color or define a custom color.
5. FolderBrowserDialog: Prompts the user to browse and select a directory/folder rather than a specific file.
(Note: These dialogs do not perform the actual opening/saving/coloring themselves; they just return the user's selection to your code.)

---

(2) List and explain any 3 Events with Example.
--> * EXPLANATION:

An Event is an action or occurrence (like a mouse click or key press) that the application can detect and respond to by executing a block of code (an Event Handler).

1. Click Event: Triggered when the user clicks on a control (most commonly used with Buttons).
2. TextChanged Event: Triggered whenever the text inside a control (like a TextBox) changes.
3. Load Event: Triggered when a Form is loaded into memory before it is displayed on the screen. Good for initialization.

 * EXPLANATION & EXAMPLE (C#):
   
   using System;
   using System.Windows.Forms;
   
   public partial class Form1 : Form {
       
       public Form1() {
           InitializeComponent();
       }
       
       // 1. Load Event Example
       private void Form1_Load(object sender, EventArgs e) {
           // Sets default text when form opens
           textBox1.Text = "Welcome"; 
       }
       
       // 2. Click Event Example
       private void button1_Click(object sender, EventArgs e) {
           // Shows a message when button is clicked
           MessageBox.Show("Button was clicked!"); 
       }
       
       // 3. TextChanged Event Example
       private void textBox1_TextChanged(object sender, EventArgs e) {
           // Copies text from textBox1 to label1 as the user types
           label1.Text = textBox1.Text; 
       }
   }

---

---

(1) Explain: DataRow.
--> A DataRow object represents a single row (record) of data within a DataTable in ADO.NET. It contains the actual data values corresponding to the columns defined in the table. You use it to add, extract, or update data in a disconnected architecture.

---

(2) Explain: DataColumn.
--> A DataColumn object represents the schema or structure of a single column within a DataTable. It defines the name of the column, its data type (e.g., integer, string), and rules or constraints (such as whether it allows null values, is read-only, or is unique).

---

(3) Explain: DataRelation.
--> A DataRelation represents a parent-child relationship between two DataTable objects within a DataSet. It acts similarly to a Foreign Key in a relational database, allowing you to navigate from a parent record to its related child records directly in memory.

(1) Explain Data Providers in ADO.Net.
--> .NET Data Providers are sets of components designed for data manipulation and fast, forward-only, read-only access to data. They act as a bridge between your application and the database.
Core objects included in a provider are:
1. Connection: Establishes a connection to a specific data source.
2. Command: Executes queries or stored procedures.
3. DataReader: Reads a forward-only stream of data from the database.
4. DataAdapter: Populates a disconnected DataSet and resolves updates with the database.
(Examples: System.Data.SqlClient for SQL Server, System.Data.OleDb for Access/Excel).

---

(2) Explain Connection object With Example.
--> The Connection Object is used to establish a physical connection to a specific data source (like a SQL Server database). It requires a connection string that contains information like the server name, database name, and authentication details. You must open the connection before performing operations and close it immediately after.

 * EXPLANATION & EXAMPLE:
   
   using System.Data.SqlClient;
   
   // Create connection string
   string conString = "Data Source=ServerName;Initial Catalog=DbName;Integrated Security=True";
   
   // Instantiate Connection object
   SqlConnection con = new SqlConnection(conString);
   
   try {
       con.Open(); // Open the connection
       // Perform database operations here...
   } finally {
       con.Close(); // Always close to release resources
   }

---

(1) Write Code to Insert Records using Disconnected Architecture.
--> * EXPLANATION:

In a Disconnected Architecture, we use a DataSet, SqlDataAdapter, and SqlCommandBuilder. The application downloads a copy of the data into memory (DataSet), adds a new DataRow, and then the DataAdapter pushes the changes back to the database.

 * CODE EXAMPLE:
   
   using System;
   using System.Data;
   using System.Data.SqlClient;
   
   class Program {
       static void Main() {
           string conStr = "Data Source=ServerName;Initial Catalog=DbName;Integrated Security=True";
           string query = "SELECT * FROM Employees";
           
           using (SqlConnection con = new SqlConnection(conStr)) {
               // 1. Create DataAdapter
               SqlDataAdapter da = new SqlDataAdapter(query, con);
               
               // 2. Automatically generate Insert/Update/Delete commands
               SqlCommandBuilder builder = new SqlCommandBuilder(da);
               
               // 3. Create and fill the DataSet
               DataSet ds = new DataSet();
               da.Fill(ds, "Employees");
               
               // 4. Create a new DataRow matching the table structure
               DataTable dt = ds.Tables["Employees"];
               DataRow newRow = dt.NewRow();
               newRow["EmpName"] = "John Doe";
               newRow["Salary"] = 50000;
               
               // 5. Add row to the disconnected DataTable
               dt.Rows.Add(newRow);
               
               // 6. Update the physical database with the new changes
               da.Update(ds, "Employees");
               
               Console.WriteLine("Record inserted successfully!");
           }
       }
   }

---

(2) Write Code to Delete Records using Connected Architecture.
--> * EXPLANATION:

In a Connected Architecture, we use the SqlConnection and SqlCommand objects. The connection is explicitly opened, a DELETE query is executed directly against the database using ExecuteNonQuery(), and the connection is closed immediately.

 * CODE EXAMPLE:
   
   using System;
   using System.Data.SqlClient;
   
   class Program {
       static void Main() {
           string conStr = "Data Source=ServerName;Initial Catalog=DbName;Integrated Security=True";
           
           // The DELETE query with a parameter to prevent SQL Injection
           string query = "DELETE FROM Employees WHERE EmpId = @Id";
           
           using (SqlConnection con = new SqlConnection(conStr)) {
               // 1. Create the Command object
               using (SqlCommand cmd = new SqlCommand(query, con)) {
                   
                   // 2. Supply the parameter value
                   cmd.Parameters.AddWithValue("@Id", 101); // Deletes employee with ID 101
                   
                   // 3. Open connection, execute, and close
                   con.Open();
                   int rowsAffected = cmd.ExecuteNonQuery();
                   con.Close();
                   
                   if (rowsAffected > 0)
                       Console.WriteLine("Record deleted successfully!");
                   else
                       Console.WriteLine("No record found with that ID.");
               }
           }
       }
   }

---

---

(1) What is File System Editor?
--> The File System Editor is a deployment tool in Visual Studio used to manage and map the folder structure of the target machine. It allows developers to specify exactly where the application's files (like .exe, .dll, and resource files) should be placed when the application is installed on a user's computer.

---

(2) What is User Interface Editor?
--> The User Interface Editor is used to customize the series of dialog boxes that the end-user sees during the installation process. Developers can add, remove, or reorder screens such as the Welcome screen, License Agreement, Installation Folder selection, and the Finished dialog.

---

(3) What is Launch Condition Editor?
--> The Launch Condition Editor is used to define prerequisites that must be met on the target machine before the installation can proceed. For example, it can check if a specific version of the .NET Framework, a certain operating system, or a required database component is installed, and abort the setup if conditions are not met.

(1) Explain Types of Reports.
--> In reporting tools (like Crystal Reports or SSRS), data can be presented in several formats. Common types include:
1. Tabular Reports: The most basic format, displaying data in simple rows and columns (like a spreadsheet).
2. Matrix/Cross-Tab Reports: Displays grouped data in a grid format, summarizing data at the intersections of rows and columns (similar to a pivot table).
3. Chart Reports: Represents data graphically using bar charts, pie charts, line graphs, etc., for quick visual analysis.
4. Drill-Down Reports: Interactive reports that allow users to click on summary data to reveal the detailed, hidden data underneath.

---

(2) Explain Setup Project.
--> A Setup Project in Visual Studio is a special type of project used to create an installer package (usually a .msi or setup.exe file) for a completed application. It bundles the compiled code, dependencies, registry keys, and necessary resources into a single distributable file, making it easy to deploy and install the software safely on end-user machines.

---

(1) Write a Program to Create and use User Control.
--> * EXPLANATION:

A User Control is a custom, reusable GUI component created by grouping together one or more existing standard Windows Forms controls. This is useful when you need the same combination of controls (like a Label paired with a TextBox) in multiple places.

 * EXPLANATION & EXAMPLE:
   
   // Part 1: Creating the User Control (Named "MyUserControl")
   // Assume you added a UserControl to your project and dragged 
   // a Label and a TextBox onto it.
   using System.Windows.Forms;
   
   public partial class MyUserControl : UserControl {
       public MyUserControl() {
           InitializeComponent(); 
       }
       
       // Creating a property to easily get/set the TextBox text
       public string InputText {
           get { return textBox1.Text; }
           set { textBox1.Text = value; }
       }
   }
   
   // Part 2: Using the User Control in a Windows Form
   using System.Drawing;
   using System.Windows.Forms;
   
   public partial class Form1 : Form {
       public Form1() {
           InitializeComponent();
           
           // Instantiate the custom User Control
           MyUserControl customControl = new MyUserControl();
           
           // Set its properties
           customControl.Location = new Point(20, 20);
           customControl.InputText = "Hello User!";
           
           // Add it to the Form's Controls collection
           this.Controls.Add(customControl);
       }
   }

---

(2) List out and Explain Types of Setup Projects.
--> * EXPLANATION:

Visual Studio provides several types of deployment projects to handle different application scenarios. The main types include:

1. Setup Project: Used to create a standard Windows Installer (.msi) for deploying desktop applications (like Windows Forms or WPF apps) to client machines.

2. Web Setup Project: Used specifically to deploy web applications, web services, and web content to an IIS (Internet Information Services) web server.

3. Merge Module Project: Creates a reusable package (.msm file) that contains components, DLLs, or files that are shared across multiple applications. These modules cannot be installed on their own; they must be merged into a standard Setup Project.

4. Setup Wizard: Not a separate project type, but rather a guided, step-by-step wizard that asks you questions about your application and automatically generates the correct type of Setup Project based on your answers.

5. CAB Project: Used to create Cabinet (.cab) files. These are primarily used for packaging components that need to be downloaded from a web browser over the internet (mostly legacy).

---