iphone 注册校验正则

//校验用户名
+ (BOOL) validateUserName : (NSString *) str
{
       NSString  *patternStr  =  [NSString  stringWithFormat:@"^.{0,4}$|.{21,}|^[^A-Za-z0-
9\u4E00-\u9FA5]|[^\\w\u4E00-\u9FA5.-]|([_.-])\1"];
    NSRegularExpression *regularexpression = [[NSRegularExpression alloc] 
                                              initWithPattern:patternStr
                                              options:NSRegularExpressionCaseInsensitive 
                                              error:nil];
    NSUInteger numberofMatch = [regularexpression numberOfMatchesInString:str 
                                                                  options:NSMatchingReportProgress
                                                                    range:NSMakeRange(0, str.length)];
    
    [regularexpression release];
    
    if(numberofMatch > 0)
    {
        return YES;
    }
    return NO;
}

//校验用户密码
+ (BOOL) validateUserPasswd : (NSString *) str
{
    
    NSRegularExpression *regularexpression = [[NSRegularExpression alloc] 
                                              initWithPattern:@"^[a-zA-Z0-9]{6,16}$"
                                              options:NSRegularExpressionCaseInsensitive 
                                              error:nil];
    NSUInteger numberofMatch = [regularexpression numberOfMatchesInString:str 
                                                                  options:NSMatchingReportProgress
                                                                    range:NSMakeRange(0, str.length)];
    
    [regularexpression release];
    
    if(numberofMatch > 0)
    {