UITextView 如何禁用选取,copy,cut

继承UITextView重写canPerformAction:withSender:方法.
-(BOOL)canPerformAction:(SEL)action withSender:(id)sender
{
[UIMenuController sharedMenuController].menuVisible = NO;  //donot display the menu
[self resignFirstResponder];                      //do not allow the user to selected anything
return NO;
}