通过设置代理的方式来去监听文本框的改变
//是否允许开始编辑
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField{
return YES;
}
//开始编辑时调用(弹出键盘)became first responder
- (void)textFieldDidBeginEditing:(UITextField *)textField{
NSLog(@"弹出键盘");
}
//是否允许结束编辑.
- (BOOL)textFieldShouldEndEditing:(UITextField *)textField{
return YES;
}
//结束编辑时调用.
- (void)textFieldDidEndEditing:(UITextField *)textField{
NSLog(@"结束编辑时调用.");
}
//是否允许文字改变.
//拦截用户输入.
- (BOOL)textField:(UITextField *)textFieldshouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
return NO;
}