网页去广告

2016/01/06 45624
webView加载网页的时候，有的时候会有广告，去除网页中的广告
// 方法一：
 - (void)showNews:(NSDictionary *)news
 {
 // 1.取出网页内容
 NSString *body = news[@"body"];

 // 2.取出图片
 NSDictionary *img = [news[@"img"] lastObject];
 NSString *imgHTML = [NSString stringWithFormat:@"<img src=\"%@\" width=\"300\" height=\"171\">", img[@"src"]];

 // 2.创建一个webView，显示网页
 UIWebView *webView = [[UIWebView alloc] init];
 webView.frame = self.view.bounds;
 [self.view addSubview:webView];

 // 3.拼接网页内容
 NSString *html = [body stringByReplacingOccurrencesOfString:img[@"ref"] withString:imgHTML];

 // 4.取出新闻标题
 NSString *title = news[@"title"];
 // 5.取出新闻的时间
 NSString *time = news[@"ptime"];

 // 头部内容
 NSString *header = [NSString stringWithFormat:@"<div class=\"title\">%@</div><div class=\"time\">%@</div>", title, time];
 html = [NSString stringWithFormat:@"%@%@", header, html];

 // 链接mainBundle中的CSS文件
 NSURL *cssURL = [[NSBundle mainBundle] URLForResource:@"news" withExtension:@"css"];
 html = [NSString stringWithFormat:@"%@<link rel=\"stylesheet\" href=\"%@\">", html, cssURL];

 // 5.加载网页内容
 [webView loadHTMLString:html baseURL:nil];
 }

// 方法二：火狐浏览器：在要去掉的广告上，右键”查看元素“，将代码粘贴到要替换的字符串处
 NSString *url = @"http://ibaby.ipadown.com/api/food/food.show.detail.php?id=";
    NSString *webSite = [url stringByAppendingString:self.Idtext];
    NSURL *siteURL= [NSURL URLWithString:webSite];
    NSURLRequest *request = [NSURLRequest requestWithURL:siteURL];
    // 加载请求
//    [self.webView.web loadRequest:request];
    dispatch_async(dispatch_get_global_queue(0, 0), ^{
        NSURLSessionDataTask *dataTask = [[NSURLSession sharedSession]dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {

            self.htmlAbosluteString = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
            self.htmlAbosluteString = [self.htmlAbosluteString stringByReplacingOccurrencesOfString:@"<img width=\"0\" height=\"0\" style=\"width: 803px; height: 121px;\" src=\"http://ubmcmm.baidustatic.com/media/v1/0f0007y3CMO4YsUwoxXbB6.jpg\"></img>" withString:@""];
// 这是要去掉广告的第二个地方
self.htmlAbosluteString = [self.htmlAbosluteString stringByReplacingOccurrencesOfString:str9 withString:@""];
            dispatch_async(dispatch_get_main_queue(), ^{
                [self.webView.web loadHTMLString:self.htmlAbosluteString baseURL:nil];
            });
        }];
        [dataTask resume];
        CGRect tmpFrame = self.webView.web.frame;
        CGFloat h = self.navigationController.navigationBar.frame.size.height + 20;
        tmpFrame.origin.y -= h;
        self.webView.web.frame = tmpFrame;
    });
// 方法三：
 NSString *str = @".jpg\" height=\"200\" width=\"340\"/>";
- (NSString *)transformMessage:(NSString *)message withString:(NSString *)string
{
    NSString *messageCopy = message;
    NSScanner *theScanner;
    NSString *text = nil;
    theScanner = [NSScanner scannerWithString:messageCopy];
    while ([theScanner isAtEnd] == NO)
    {
         // find start of tag
        [theScanner scanUpToString:@".jpg" intoString:NULL] ;
         // find end of tag
        if ([theScanner scanUpToString:@">" intoString:&text] || [theScanner scanUpToString:@"/>" intoString:&text]) {
            // .jpg" height="200" width="340"/>
            // 如果不需要第二个参数 ：
            // 可以将string替换为 [NSString stringWithFormat:@".jpg\" height=\\\"200\" width=\"340\"/>"]
            if (text != nil) {
                messageCopy = [messageCopy stringByReplacingOccurrencesOfString:[NSString stringWithFormat:@"%@>", text] withString:string];
                NSLog(@"%@",messageCopy);
                break;
            }
        }
    }
    return messageCopy;
}
作用是把start tag和end tag 之间替换成string的值
代码片段
