当我们遇到后台返回的是一串html'字符串，这个字符串中包含的有imgURL标签和文字，而需要是把文字和图片分别展示出来， 这个时候就需要先把里面的图片url提取出来，然后在使用imageView展示。现在问题的关键是如何把所有的imgURL拿出来呢？ 其实很简单， 一个正确的正则表达式 <(img|IMG)(.*?)(/>|></img>|>) 即可实现我们要的效果
顺便附上一个移除html标签的方法

具体代码如下 返回的是这串字符串里面所有的图片地址 所有是一个集合

- (NSArray *)filterImageUrlFromHTML:(NSString *)html
{
    NSMutableArray *resultArray = [NSMutableArray array];

        NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"<(img|IMG)(.*?)(/>|></img>|>)" options:NSRegularExpressionAllowCommentsAndWhitespace error:nil];
        NSArray *result = [regex matchesInString:html options:NSMatchingReportCompletion range:NSMakeRange(0, html.length)];
        
        for (NSTextCheckingResult *item in result) {
            NSString *imgHtml = [html substringWithRange:[item rangeAtIndex:0]];
            
            NSArray *tmpArray = nil;
            if ([imgHtml rangeOfString:@"src=\""].location != NSNotFound) {
                tmpArray = [imgHtml componentsSeparatedByString:@"src=\""];
            } else if ([imgHtml rangeOfString:@"src="].location != NSNotFound) {
                tmpArray = [imgHtml componentsSeparatedByString:@"src="];
            }
            
            if (tmpArray.count >= 2) {
                NSString *src = tmpArray[1];
                
                NSUInteger loc = [src rangeOfString:@"\""].location;
                if (loc != NSNotFound) {
                    src = [src substringToIndex:loc];
                    [resultArray addObject:src];
                }
            }
        }

    return resultArray;
}

移除html字符串中的标签

- (NSString *)removeHTMLFromStr:(NSString *)html{

    NSArray *components = [html componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@"<>"]];

    

    NSMutableArray *componentsToKeep = [NSMutableArray array];

    for (int i = 0; i < [components count]; i = i + 2) {

        [componentsToKeep addObject:[components objectAtIndex:i]];

    }

    

    NSString *plainText = [componentsToKeep componentsJoinedByString:@""];

    return plainText;

}