我们可以在请假事件中得到控制吗？

Question

When i want to get an control, i can type like this (exp listview):

ListView lst = (ListView)this.ActiveControl;

But in Leave event, I can't write like that.
So can somebody help me how to get a control at Leave event? In Leave event it say that control is no longer active. How can we get a control by the way above?

Answer 1

Error occurs because when a control has lost the focus, then it is not active any more. If you want to use your last active control, you can save it using Enter event and use it in Leave :

Define a variable inside class:

Control ctlActive = null;

Inside Enter event:

ctlActive = this.ActiveControl;
// OR:
ctlActive = sender as Control;

Inside Leave event:

if (ctlActive != null && ctlActive is ListView)
{
    var lst = ctlActive as ListView;
    // do something...
}
//...
ctlActive = null;