Question

我想在textfield中输入字母数字值。如果用户只输入字符或数字，则发送按摩。即使没有特殊字符可以接受。

        NSString *str = askIdTxt.text;
        NSCharacterSet *alphanumericSet = [NSCharacterSet alphanumericCharacterSet];
        NSCharacterSet *numberSet = [NSCharacterSet decimalDigitCharacterSet];
        BOOL isAlphaNumericOnly = [[str stringByTrimmingCharactersInSet:alphanumericSet] isEqualToString:@""] && ! [[str stringByTrimmingCharactersInSet:numberSet] isEqualToString:@""];
        if (isAlphaNumericOnly) {
             NSLog(@"isAplhaNumericOnly: %@",(isAlphaNumericOnly? @"Yes":@"No"));
        }

这总是回归真实。我没有弄错。

Answer 1

如何使用正则表达式：

-(BOOL)isAlphaNumericOnly:(NSString *)input 
{
    NSString *alphaNum = @"[a-zA-Z0-9]+";
    NSPredicate *regexTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", alphaNum];

    return [regexTest evaluateWithObject:input];
}

然后使用它

if([self isAlphaNumeric:str])
{
    NSLog(@"IT IS ALPHA NUMERIC STRING");

}

修改相同的技术可用于验证密码，您只需要更好的正则表达式：

-(BOOL)isPasswordStrong:(NSString *)password { /* 8-20 chars at least one letter at least one number OR special character no more than 3 repeated characters */ NSString *strongPass= @"^(?!.*(.)\\1{3})((?=.*[\\d])(?=.*[A-Za-z])|(?=.*[^\\w\\d\\s])(?=.*[A-Za-z])).{8,20}$";; NSPredicate *regexTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", strongPass]; return [regexTest evaluateWithObject:password]; }

使用正则表达式可以创建不同的规则，但这可以为您提供一个先机，

Answer 2

 Call this Method and modify it accordingly .....


   -(BOOL) isPasswordValid:(NSString *)pwd 
     {

       if ( [pwd length]<4 || [pwd length]>20 ) return NO;  // too long or too short
       NSRange rang;
       rang = [pwd rangeOfCharacterFromSet:[NSCharacterSet letterCharacterSet]];
       if ( !rang.length ) return NO;  // no letter
       rang = [pwd rangeOfCharacterFromSet:[NSCharacterSet decimalDigitCharacterSet]];
       if ( !rang.length )  return NO;  // no number;
       return YES;

     }

Answer 3

我想问题出在alphanumericCharacterSet，这里是a part from doc：

非正式地，此集合是用作基本单位的所有字符的集合字母，音节，表意文字和数字。

所以，我希望它会允许你不想要的角色。

您也可以尝试使用Regex：

NSError *error = nil;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"^[a-z\\d]+$" options:NSRegularExpressionCaseInsensitive error:&error];
NSUInteger matches = [regex numberOfMatchesInString:str options:NSMatchingReportCompletion range:NSMakeRange(0, [str length])];

BOOL hasMatches = (matches > 0) && !error;

Answer 4

试试这个

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{

        NSCharacterSet *charactersToBlock = [[NSCharacterSet alphanumericCharacterSet] invertedSet];
        return ([string rangeOfCharacterFromSet:charactersToBlock].location == NSNotFound);
}

Answer 5

试试这个：

NSCharacterSet *blockedCharacters = [[[NSCharacterSet alphanumericCharacterSet] invertedSet] retain];

- (BOOL)textField:(UITextField *)field shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)characters
{
    return ([characters rangeOfCharacterFromSet:blockedCharacters].location == NSNotFound);
}

验证UITextField中的字母数字值

5 个答案: