在代理方法中, 判断UITextField/UITextView字数总是不正确
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
通过对TextField/View监听事件能准确获取字数, 在回调方法中处理按钮考虑、是否可点等动作
[self.mobileTextField addTarget:self action:@selector(textValueDidChanged) forControlEvents:UIControlEventEditingChanged];
//Action方法
- (void)textValidChanged
{
self.verificationCodeButton.enabled = NO;
self.submitButton.enabled = NO;
self.submitButton.enabled = (self.mobileTextField.text.length >= 11) && (self.VerificationCodeTextField.text.length > 0);
self.verificationCodeButton.enabled = self.mobileTextField.text.length >= 11;
self.verificationCodeButton.backgroundColor = self.verificationCodeButton.enabled ? QDYellowColor : ButtonGrayColor;
}
