在IOS开发中有时会用到Object和javaScript相互调用,具体步骤如下:
1. Object中执行javascript代码,这个比较简单,苹果提供了很好的方法
- (NSString *)stringByEvaluatingJavaScriptFromString:(NSString *)script
2. javascript执行过程中返回给Object的数据或者调用Object方法,这个时候就需要用到UIWebView的地址重定向功能,主要代码如下:
(1)创建UIWebView
webView = [[UIWebView alloc] initWithFrame:self.view.bounds]; webView.delegate = self; [self.view addSubview:webView]; [self loadWebPageWithString:_url]; - (void)loadWebPageWithString:(NSString*)urlString { NSURL *url =[NSURL URLWithString:urlString]; NSURLRequest *request =[NSURLRequest requestWithURL:url]; [webView loadRequest:request]; }
#pragma mark - UIWebViewDelegate - (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType { NSString *urlString = [[request URL] absoluteString]; debuglog(@"urlString = %@",urlString); NSString *prefix = @"myvideo"; if ([urlString hasPrefix:prefix]) { NSString *endString = [urlString substringFromIndex:7]; debuglog(@"last urlString = %@",endString); return NO; } return YES; } - (void)webViewDidStartLoad:(UIWebView *)webView { } - (void)webViewDidFinishLoad:(UIWebView *)webView { [self excuteJavaScript]; } - (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error { } - (void)excuteJavaScript { NSString *js = @"var video = document.getElementsByTagName(‘video‘)[0];setTimeout(getVideo,1000); function getVideo(){ video = document.getElementsByTagName(‘video‘)[0];if(video==undefined){setTimeout(getVideo,1000);}else{ video.pause();if(video.src==‘‘){var video = document.getElementsByTagName(‘source‘)[0];}document.location = ‘myvideo‘+ video.getAttribute(‘src‘);injectedObject.playVideo(video.getAttribute(‘src‘));}}"; [webView stringByEvaluatingJavaScriptFromString:js]; }
说明如下:
(1)在UIWebView加载完网页的时候,即执行到webViewDidFinishLoad代理的时候,执行一段javascript代码,这段代码的作用是获取网页中的视频地址,代码中“ document.location = ‘myvideo‘+ video.getAttribute(‘src‘); ”这段特别重要,document.location是为了做地址重定向用的,执行完这段javascript代码,接着就会执行
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType 这个代理方法,其中就会捕获到document.location给出的地址即‘myvideo‘+ video.getAttribute(‘src‘); 。你可以去掉‘myvideo‘头,就可以得到你需要的东西了,其中‘myvideo‘是你自己定义的一个头,是为了便于解析后面的数据。
原文地址:http://blog.csdn.net/chchong1234/article/details/24656257