窗口传值Delegate

Posted 2020-11-02 stoneg

• 主窗口实现Handler

private void DisplayMessageHandler(string strmes, Color color)
        {
            label1.Text = strmes;
            label1.BackColor=color;
            label1.Refresh();
            Application.DoEvents();
        }

private void DisplayMessageDelegate(string msg, Color color)
        {
            if (this.InvokeRequired)    //are we running on a secondary thread
            {
                //Make arguments for delegate
                Object[] args = new Object[] { msg, color };

                //Make the delegate
                DisplayMessage dm = new DisplayMessage(DisplayMessageHandler);
                this.Invoke(dm,args);
            }
            else
            {
                DisplayMessageHandler(msg,color);
            }
        }

private void OnUpdateWindow(string msg, Color color)
        {
            DisplayMessageDelegate(msg, color);
        }

• 在主窗口代码中声明委托

private delegate void DisplayMessage(string msg, Color color);

• 在副窗口中声明委托

public delegate void UpdateWindowDelegate(string msg, Color color   );
        public static UpdateWindowDelegate UpdateWindow;

• 在副窗口中调用委托

private void UpdateMsg(string msg, Color color)
        {
            UpdateWindowDelegate uw = UpdateWindow;
            if (uw != null) UpdateWindow(msg, color);
        }

• 在主窗口中声明副窗口中的委托

Form2.UpdateWindow += new Form2.UpdateWindowDelegate(OnUpdateWindow);