- (NSUInteger)analyseRX:(NSString *)string withPatternString:(NSString *)patternString {     //     \\[[^\\]]+\\]  用以匹配字符串中所出现的 [*] 的个数     //     <[^>]+>        用以匹配字符串中所出现的 <*> 的个数     if (string == nil)     {         return 0;     }     // 正则表达式     NSRegularExpression *regex = \         [NSRegularExpression regularExpressionWithPattern:patternString                                                   options:NSRegularExpressionCaseInsensitive                                                     error:nil];     // 执行相关匹配操作     NSRange range = NSMakeRange(0, [string length]);     NSUInteger numberOfMatches = [regex numberOfMatchesInString:string                                                         options:0                                                           range:range];     // 返回匹配的个数     return numberOfMatches; }