⚡ C# Asynchronous Programming

Asynchronous programming allows the program to execute tasks without blocking the main thread. In C#, this is done using async and await keywords.

📂 Example: Async Method with Delay

using System;
using System.Threading.Tasks;

class Program {
    static async Task Main(string[] args) {
        Console.WriteLine("Starting operation...");
        await LongRunningOperation();
        Console.WriteLine("Operation completed!");
    }

    static async Task LongRunningOperation() {
        Console.WriteLine("Task is running...");
        await Task.Delay(3000); // Simulates 3-second delay
        Console.WriteLine("Task finished after 3 seconds.");
    }
}

🔑 Pro Tip: The await keyword pauses the method execution until the awaited task completes, without blocking the main thread.

📂 Example: Asynchronous File Reading

using System;
using System.IO;
using System.Threading.Tasks;

class Program {
    static async Task Main(string[] args) {
        string filePath = "example.txt";
        string content = await ReadFileAsync(filePath);
        Console.WriteLine(content);
    }

    static async Task<string> ReadFileAsync(string path) {
        using (StreamReader reader = new StreamReader(path)) {
            string content = await reader.ReadToEndAsync();
            return content;
        }
    }
}

💡 Async file operations prevent freezing of the main thread while I/O tasks are in progress.

🚀 Why Use Async Programming?

Non-blocking: Keeps UI/apps responsive during long tasks.
Improves performance: Other tasks can run while waiting.
Better UX: Smooth, lag-free experiences in GUI apps.

🧠 Quiz: Test Your Knowledge

1. What does the async keyword indicate in a method?

The method will be executed asynchronously and can use await.
The method will block the main thread until it completes.
The method will not return any value.

2. What is the purpose of the await keyword?

It waits for the asynchronous task to complete before continuing execution.
It makes the task execute in parallel with other tasks.
It pauses the execution of the program until the task finishes.

3. How does asynchronous programming improve performance?

It allows other tasks to run while waiting for a long-running operation to complete.
It prevents the program from executing any code until all tasks are completed.
It makes the program execute more tasks in a linear fashion.

4. Which is a benefit of async programming in GUI apps?

The UI remains responsive while performing time-consuming operations.
It prevents any errors from occurring in the program.
It forces the program to run in a sequential manner.

5. In the async file reading example, what does ReadFileAsync return?

The content of the file as a string.
The file path.
An error message if the file is not found.

Quiz results will appear here...

⚡ Async/await is a must-have for modern C# applications that deal with files, APIs, or anything that takes time.