UIWebView

self.webView = [[UIWebView alloc]initWithFrame:self.view.bounds];

    self.webView.autoresizingMask = UIViewAutoresizingFlexibleHeight;

    [self.view addSubview:self.webView];

    self.webView.userInteractionEnabled = YES;

    self.webView.delegate = self;

    self.webView.scalesPageToFit =  YES;webView大小适配屏幕

NSURL *url = [NSURL URLWithString:_requstUrl];

    NSURLRequest *request = [NSURLRequest requestWithURL:url];

NSURLRequest *request = [NSURLRequest requestWithURL:url cachePolicy: NSURLRequestReloadIgnoringCacheData timeoutInterval:10];

可以自己进行网络请求 也可停止 是异步的

[self.webView loadRequest:request];