Refactoring event-driven code in C# with better asynchronous patterns
I'm updating my dependencies and I'm building a feature where I'm dealing with While refactoring a legacy C# WinForms application, I've come across a significant amount of event-driven code that handles complex asynchronous operations. The existing implementation relies heavily on blocking calls which negatively affects performance and responsiveness. For instance, I found pieces of code like this: ```csharp private void Button_Click(object sender, EventArgs e) { // Blocking call var result = LongRunningOperation(); MessageBox.Show(result); } private string LongRunningOperation() { Thread.Sleep(5000); // Simulating a long-running operation return "Operation Complete!"; } ``` It’s clear that this approach can be improved by utilizing asynchronous programming patterns. I've tried using `async` and `await` to make the button click event fire an asynchronous method: ```csharp private async void Button_Click(object sender, EventArgs e) { var result = await LongRunningOperationAsync(); MessageBox.Show(result); } private async Task<string> LongRunningOperationAsync() { await Task.Delay(5000); // Simulating a long-running operation return "Operation Complete!"; } ``` However, this led to issues where the UI thread was not updating correctly when the operation completed. I suspect that something in my event wiring may not be properly synchronized with the UI thread. Additionally, in some parts of the application, there are nested event handlers that also call blocking methods, which complicates the flow. One solution I considered was to implement `IProgress<T>` to report progress back to the UI without needing to manually invoke the UI thread. Still, I'm unsure how to integrate that seamlessly into the existing event-driven model. Has anyone tackled similar issues while refactoring legacy event-driven C# code? What strategies did you find effective for maintaining responsiveness during async operations, and how did you handle event handlers in this context? This issue appeared after updating to C# 3.10. Cheers for any assistance! My development environment is Windows 10. What's the correct way to implement this?