uitextfield 监听变化，

-(IBAction)editingChange:(id)sender

{

    UITextField *textField = (UITextField *)sender;

    if (textField.text.length == 11) {

        [self loadWinner:textField.text];

        [self.searchFieldresignFirstResponder];

    }

    if (textField.text.length > 0) {

        self.clearBtn.hidden = NO;

    }else{

        self.clearBtn.hidden = YES;

    }

 

}