msdn上的一段代码
// This method demonstrates a pattern for making thread-safe
// calls on a Windows Forms control.
//
// If the calling thread is different from the thread that
// created the TextBox control, this method creates a
// SetTextCallback and calls itself asynchronously using the
// Invoke method.
//
// If the calling thread is the same as the thread that created
// the TextBox control, the Text property is set directly.
delegate void SetTextCallback(string text);//内部线程委托
private void SetText(string text)
{
// InvokeRequired required compares the thread ID of the
// calling thread to the thread ID of the creating thread.
// If these threads are different, it returns true.
if (this.textBox1.InvokeRequired)//判断是否是内部线程调用
{
SetTextCallback d = new SetTextCallback(SetText);//外部线程创建委托
this.Invoke(d, new object[] { text });//使用委托进行递归调用
}
else
{
this.textBox1.Text = text;//内部线程设置文本内容
}
}
