iOS UITextField限制输入字数

关于iOS的文本框有时需要限制字数，如手机号，在UITextField的代理单纯写一个判断，在字数超过限制时，这时再想删除就删除不掉，可以在代理这样写，就解决

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{  if (!string.length)  {    return YES;  }    if (textField.keyboardType == UIKeyboardTypeNumberPad)  {    if ([string rangeOfCharacterFromSet:[[NSCharacterSet decimalDigitCharacterSet] invertedSet]].location != NSNotFound)    {      return NO;    }  }    NSString *updatedText = [textField.text stringByReplacingCharactersInRange:range withString:string];    if (updatedText.length > 11) // 4 was chosen for SSN verification  {    if (string.length > 1)    {      // BasicAlert(@"", @"This field accepts a maximum of 4 characters.");    }        return NO;  }    return YES;}

原标题：iOS UITextField限制输入字数

关键词：IOS