During my .Net journey, I had to face the transistion to asynchronous programming with c# async/await keywords, at first sight, it looks like realy easy, but when digging a bit further, some concernes have to be carified. Let’s start with the basics.
c# async/await : understanding asynchronous programming in .Net
Asynchronous programming in C# is a crucial skill for writing efficient and responsive applications. The async and await keywords in C# simplify working with asynchronous operations, making code easier to read and maintain.
c# async/await, why to use that ?
Before async / await asynchronous programming in C# relied on callbacks or the task based Asynchronous Pattern (TAP), which often resulted in complex and hard-to-follow code. async / await provides a more readable and structured way to handle asynchronous execution, reducing callback nesting and improving maintainability.
Basic Usage of async and await
To define an asynchronous method, use the async keyword before the method’s return type. The await keyword is then used inside the method to asynchronously wait for a task to complete without blocking the main thread.
Example
|
1 2 3 4 5 6 7 8 |
public async Task<int> FetchDataAsync() { HttpClient client = new HttpClient(); string result = await client.GetStringAsync("https://api.example.com/data"); return result.Length; } |
Here, GetStringAsync is awaited, allowing the method to pause execution until the HTTP request completes while freeing up the thread for other tasks.
Handling asynchronous execution
When using async / await, consider the following best practices, they are more rules that advice :
- Use ConfigureAwait(false) : This avoids unnecessary context capturing and improves performance.
- Avoid async void except for event handlers : Use Task or Task<T> for better error handling.
- Be mindful of exceptions : Wrap
calls in try/catch blocks to handle errors properly.123await
Example
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 |
public async Task ProcessDataAsync() { try { int length = await FetchDataAsync(); Console.WriteLine($"Data length: {length}"); } catch (Exception ex) { Console.WriteLine($"Error: {ex.Message}"); } } |
Conclusion
Using C# async/await correctly helps build more scalable and responsive applications. By following best practices and understanding its behavior, you can efficiently manage asynchronous operations while maintaining clean and readable code.
For more information, you can refer to Stephen Cleary’s blog post. I’ll post some other topics about asynchronous programming in .Net sooner with some concepts like transforming an app to an async one, fire and forget, etc.