// 自适应尺寸大小
+ (NSString *)autoWebAutoImageSize:(NSString *)html{
    
    NSString * regExpStr = @"<img\\s+.*?\\s+(style\\s*=\\s*.+?\")";
    NSRegularExpression *regex=[NSRegularExpression regularExpressionWithPattern:regExpStr options:NSRegularExpressionCaseInsensitive error:nil];
    
    NSArray *matches=[regex matchesInString:html
                                    options:0
                                      range:NSMakeRange(0, [html length])];
    
    
    NSMutableArray * mutArray = [NSMutableArray array];
    for (NSTextCheckingResult *match in matches) {
        NSString* group1 = [html substringWithRange:[match rangeAtIndex:1]];
        [mutArray addObject: group1];
    }
    
    NSUInteger len = [mutArray count];
    for (int i = 0; i < len; ++ i) {
        html = [html stringByReplacingOccurrencesOfString:mutArray[i] withString: @"style=\"width:90%; height:auto;\""];
    }
    
    return html;
}