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:(
control ,change focus:(使用 tab ,shift + tab等等，或是调用Select,SelectNextControl，或是使用当前form的ActiveControl))
Enter
GotFocus
Leave
Validating
Validated
LostFocus
鼠标周期:(control ,change focus:(使用鼠标，或是通过调用Focus方法))
Enter
GotFocus
LostFocus
Leave
Validating
Validated