后台返回的字符串中包含了Html标签，逐个处理实在太麻烦，也不提倡。
以下是项目中使用的过滤Html标签方法。

+ (NSString *)filterHTML:(NSString *)html {

    NSScanner *theScanner;
    NSString *text = nil;

    theScanner = [NSScanner scannerWithString:html];

    while ([theScanner isAtEnd] == NO) {
       
        [theScanner scanUpToString:@"<" intoString:NULL] ;
        
        [theScanner scanUpToString:@">" intoString:&text] ;
       
        html = [html stringByReplacingOccurrencesOfString:
                [NSString stringWithFormat:@"%@>", text]
                                               withString:@""];
    }
    return html;
}