C#如何触发回调？

Question

这是我的代码片段的一部分。我想将回调函数传递给 test()。因此，在调用“del”委托(delegate)后，是否可以自动触发回调()？

函数:

butOK_Click()  //when click the button, disable it
test()  //a wrapper function calling updateUI function
updateUI() // a long process function
callback() // a callback function enabling the button back

我该怎么做？谢谢

public delegate void updateUIDelegate(bool refresh);
public delegate void asyncCallback();            
//...
void butOK_Click(object sender, EventArgs e) {
    butOK.Enabled = false;
    test();
} 
public void updateUI() {
    // long function....doing 10s
}
public void callback() {
    butOK.Enabled = true;
}
public void test() {
    updateUIDelegate del = new updateUIDelegate(updateUI);
    del.BeginInvoke(null,null);
    //??????????
}

Answer 1

请尝试以下操作:

void button1_Click(object sender, EventArgs e) {
    button1.Enabled = false;
    BeginAsyncOperation(updateUI);
}
void BeginAsyncOperation(Action operation) {
    operation.BeginInvoke(OnAsyncCallback, null);
}
void OnAsyncCallback(IAsyncResult result) {
    if(result.IsCompleted) {
        if(!InvokeRequired)
            callback();
        else BeginInvoke(new Action(callback));
    }
}
//
public void callback() {
    button1.Enabled = true;
    // something else
}
public void updateUI() {
    // long function....doing 10s
    System.Threading.Thread.Sleep(10000);
}

另请参阅以下文章:Calling Synchronous Methods Asynchronously