窗体启动时:
Control.HandleCreated
Control.BindingContextChanged
Form.Load
Control.VisibleChanged
Form.Activated
Form.Shown
窗体关闭时:
Form.Closing
Form.FormClosing
Form.Closed
Form.FormClosed
Form.Deactivate
控件焦点与验证事件:
Enter
GotFocus
Leave
Validating
Validated
LostFocus
使用鼠标:
Enter
GotFocus
LostFocus
Leave
Validating
Validated