在实际开发过程中，经常会遇到些不能让用户随便地输入手机号码，对输入的手机号码的正确判断；有些输入框只能输入数字，不能输入字母或特殊字符；还有些如价格金额之类的就只能输入数字和小数点且小数点后面保留两位。

///// 手机号码的有效性判断  //检测是否是手机号码  - (BOOL)isMobileNumber:(NSString *)mobileNum  {      /**       * 手机号码       * 移动：134[0-8],135,136,137,138,139,150,151,157,158,159,182,187,188       * 联通：130,131,132,152,155,156,185,186       * 电信：133,1349,153,180,189       */      NSString * MOBILE = @"^1(3[0-9]|5[0-35-9]|8[025-9])\\d{8}$";      /**       10         * 中国移动：China Mobile       11         * 134[0-8],135,136,137,138,139,150,151,157,158,159,182,187,188       12         */      NSString * CM = @"^1(34[0-8]|(3[5-9]|5[017-9]|8[278])\\d)\\d{7}$";      /**       15         * 中国联通：China Unicom       16         * 130,131,132,152,155,156,185,186       17         */      NSString * CU = @"^1(3[0-2]|5[256]|8[56])\\d{8}$";      /**       20         * 中国电信：China Telecom       21         * 133,1349,153,180,189       22         */      NSString * CT = @"^1((33|53|8[09])[0-9]|349)\\d{7}$";      /**       25         * 大陆地区固话及小灵通       26         * 区号：010,020,021,022,023,024,025,027,028,029       27         * 号码：七位或八位       28         */      // NSString * PHS = @"^0(10|2[0-5789]|\\d{3})\\d{7,8}$";        NSPredicate *regextestmobile = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", MOBILE];      NSPredicate *regextestcm = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", CM];      NSPredicate *regextestcu = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", CU];      NSPredicate *regextestct = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", CT];        if (([regextestmobile evaluateWithObject:mobileNum] == YES)          || ([regextestcm evaluateWithObject:mobileNum] == YES)          || ([regextestct evaluateWithObject:mobileNum] == YES)          || ([regextestcu evaluateWithObject:mobileNum] == YES))          {          return YES;          }      else          {          return NO;          }  }    //////// 特殊字符的限制输入，价格金额的有效性判断    #define myDotNumbers     @"0123456789.\n"  #define myNumbers          @"0123456789\n"  -(void) createTextFiled {      textfield1_ = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, 20, 20)];      textfield1_.delegate = self;      [self addSubview:textfield1_];         textfield2_ = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, 20, 20)];      textfield2_.delegate = self;      [self addSubview:textfield2_];         textfield3_ = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, 20, 20)];      textfield3_.delegate = self;      [self addSubview:textfield3_];    }    -(void)showMyMessage:(NSString*)aInfo {        UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"提示" message:aInfo delegate:self cancelButtonTitle:@"确定" otherButtonTitles:nil, nil];      [alertView show];      [alertView release];    }    - (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {      NSCharacterSet *cs;      if ([textField isEqual:textfield1_]) {          cs = [[NSCharacterSet characterSetWithCharactersInString:myNumbers] invertedSet];          NSString *filtered = [[string componentsSeparatedByCharactersInSet:cs] componentsJoinedByString:@""];          BOOL basicTest = [string isEqualToString:filtered];          if (!basicTest) {              [self showMyMessage:@"只能输入数字"];              return NO;          }      }      else if ([textField isEqual:textfield2_]) {          cs = [[NSCharacterSet characterSetWithCharactersInString:myNumbers] invertedSet];          NSString *filtered = [[string componentsSeparatedByCharactersInSet:cs] componentsJoinedByString:@""];          BOOL basicTest = [string isEqualToString:filtered];          if (!basicTest) {              [self showMyMessage:@"只能输入数字"];              return NO;          }      }      else if ([textField isEqual:textfield3_]) {          NSUInteger nDotLoc = [textField.text rangeOfString:@"."].location;          if (NSNotFound == nDotLoc && 0 != range.location) {              cs = [[NSCharacterSet characterSetWithCharactersInString:myDotNumbers] invertedSet];          }          else {              cs = [[NSCharacterSet characterSetWithCharactersInString:myNumbers] invertedSet];          }          NSString *filtered = [[string componentsSeparatedByCharactersInSet:cs] componentsJoinedByString:@""];          BOOL basicTest = [string isEqualToString:filtered];          if (!basicTest) {                [self showMyMessage:@"只能输入数字和小数点"];              return NO;          }          if (NSNotFound != nDotLoc && range.location > nDotLoc + 3) {              [self showMyMessage:@"小数点后最多三位"];              return NO;          }      }      return YES;  }