iOS 手机号码344格式的TextField

1、首先给TextField注册通知

    [_mobileTextFeild addTarget:self action:@selector(textFieldChange:) forControlEvents:UIControlEventEditingChanged];

2、定义成员变量

    NSString *previousTextFieldContent;
    UITextRange *previousSelection;

3、实现

- (void)textFieldChange:(TsaaTextField *)sender{
    
    if (sender == self.mobileTextFeild) {
        
        UITextField *textField = (UITextField *)sender;
          //限制手机账号长度13位（有两个空格）
        NSUInteger targetCursorPosition = [textField offsetFromPosition:textField.beginningOfDocument toPosition:textField.selectedTextRange.start];

          if (textField.text.length > 13) {
              textField.text = self.oldMobile;
              UITextPosition *targetPosition = [textField positionFromPosition:[textField beginningOfDocument] offset:targetCursorPosition - 1];
              [textField setSelectedTextRange:[textField textRangeFromPosition:targetPosition toPosition :targetPosition]];
              return;
          }


          NSString *currentStr = [textField.text stringByReplacingOccurrencesOfString:@" " withString:@""];
          NSString *preStr = [previousTextFieldContent stringByReplacingOccurrencesOfString:@" " withString:@""];

          //正在执行删除操作时为0，否则为1
          char editFlag = 0;
          if (currentStr.length <= preStr.length) {
              editFlag = 0;
          }else{
              editFlag = 1;
          }


          NSMutableString *tempStr = [NSMutableString new];

          int spaceCount = 0;
          if (currentStr.length < 3 && currentStr.length > -1) {
              spaceCount = 0;
          }else if (currentStr.length < 7 && currentStr.length > 2) {
              spaceCount = 1;
          }else if (currentStr.length < 12 && currentStr.length > 6) {
              spaceCount = 2;
          }

          for (int i = 0; i < spaceCount; i++) {
              if (i == 0) {
                  [tempStr appendFormat:@"%@%@", [currentStr substringWithRange:NSMakeRange(0, 3)], @" "];
              }else if (i == 1) {
                  [tempStr appendFormat:@"%@%@", [currentStr substringWithRange:NSMakeRange(3, 4)], @" "];
              }else if (i == 2) {
                  [tempStr appendFormat:@"%@%@", [currentStr substringWithRange:NSMakeRange(7, 4)], @" "];
              }
          }

          if (currentStr.length == 11) {
              [tempStr appendFormat:@"%@%@", [currentStr substringWithRange:NSMakeRange(7, 4)], @" "];
          }
          if (currentStr.length < 4) {
              [tempStr appendString:[currentStr substringWithRange:NSMakeRange(currentStr.length - currentStr.length % 3, currentStr.length % 3)]];
          }else if(currentStr.length > 3 && currentStr.length <12) {
              NSString *str = [currentStr substringFromIndex:3];
              [tempStr appendString:[str substringWithRange:NSMakeRange(str.length - str.length % 4, str.length % 4)]];
              if (currentStr.length == 11) {
                  [tempStr deleteCharactersInRange:NSMakeRange(13, 1)];
              }
          }
          textField.text = tempStr;
        self.oldMobile = textField.text;

          // 当前光标的偏移位置
          NSUInteger curTargetCursorPosition = targetCursorPosition;

          if (editFlag == 0) {
              //删除
              if (targetCursorPosition == 9 || targetCursorPosition == 4) {
//                  curTargetCursorPosition = targetCursorPosition - 1;
              }
          }else {
              //添加
                 if (targetCursorPosition == 8 || targetCursorPosition == 4) {
                     curTargetCursorPosition = targetCursorPosition + 1;
                 }
              if (textField.text.length > 9) {
                  if (targetCursorPosition == 9) {
                      curTargetCursorPosition = targetCursorPosition + 1;
                  }
              }
          }
          UITextPosition *targetPosition = [textField positionFromPosition:[textField beginningOfDocument] offset:curTargetCursorPosition];
          [textField setSelectedTextRange:[textField textRangeFromPosition:targetPosition toPosition :targetPosition]];
        
        if (self.mobileTextFeild.text.length >= 13) {
            self.mobileTextFeild.text = [self.mobileTextFeild.text substringToIndex:13];
            self.accountVerify = YES;
            [self changeConfirmButton];
            return;
        } else {
            self.accountVerify = NO;
            [self changeConfirmButton];
        }
    }
}

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    if (textField == self.mobileTextFeild) {
        previousTextFieldContent = textField.text;
        previousSelection = textField.selectedTextRange;
    }
    return YES;
}