How Can I Avoid Cross-Thread Exceptions When Updating UI Controls from Background Threads?

Detailed explanation of cross -threading abnormality

When performing operations related to UI, the principle of single -threading must be obeyed: UI controls can only be accessed by thread creation. Try to access controls from other threads will cause "invalid cross -threading operation" abnormalities.

Problem solution

In the sample scenario, the data dense operation is performed in the background thread, and the error occurred when the background thread access attribute in the code 1.

The solution is to use the textbox1.text and

methods to ensure that access control on the correct thread. In Code 2, we check whether

is true, indicating that the current thread is not a thread to create a control. If so, use the method to perform necessary actions on the main thread. InvokeRequired Invoke InvokeRequired The influence of the sentence Invoke

In the first line of the code 2, check whether the attribute is true. If so, it means that the current thread is not a thread that creates a control. In this case, the method will be called, which arranges a commission to execute on the right thread. InvokeRequired Execute the statement and the subsequent

call will cause the execution to be briefly switched to the main thread, and then return to the background thread. This context switch may cause the application to seem unspeakable.

InvokeRequired Settling solution Invoke

In order to minimize the effects of thread switching and ensure efficient execution of UI -related operations, we can perform the following operations: InvokeRequired Invoke

Try to call any operation on the main thread

Before , access the control attribute in the background thread and perform all the necessary processing.

Only when necessary (for example, when the results of the background processing update UI) use the

method.

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