JS代码和OC代码的相互调用

JS调用OC

很多应用里面或多或少的调用了网页，来达到绚丽的效果，所谓的JS调用OC.....举个例子吧，网页上有个按钮

点击按钮跳转界面，跳转的动作由OC的代码实现。

OC调用JS

还是举个例子，我们OC代码创建了输入框比如输入用户名，输入完成后显示在网页上，显示用户的用户名

一.利用webView的代理方法实现OC和JS的相互调用

创建属性

@property(nonatomic,strong)UIWebView * webView;

遵守webView的协议UIWebViewDelegate

-(void)webViewLoad{

    NSURL * url = [[NSURL alloc]initWithString:@"http://www.baidu.com"];
    self.webView = [[UIWebView alloc]initWithFrame:self.view.bounds];
    NSURLRequest * request = [[NSURLRequest alloc]initWithURL:url];
    self.webView.delegate = self;
    [self.webView loadRequest:request];

    [self.view addSubview:self.webView];

}

//JS调用OC
-(BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType{
    NSString * str = request.URL.relativeString;
    if ([str isEqualToString:@"http://www.baidu.com/"]) {
       NSLog(@"来找度娘");
    }
    return YES;
}
//OC调用JS
-(void)webViewDidFinishLoad:(UIWebView *)webView{
   NSString * str = [self.webView stringByEvaluatingJavaScriptFromString:@"document.getElementById(""\"index-kw""\").value=""\"li""\""];
    NSLog(@"webViewDidFinishLoad=%@",str);

}

二.利用第三方的框架实现(需要你和html端的人统一方法的名称)

-(void)webViewBridge{
    self.webView = [[UIWebView alloc]initWithFrame:[UIScreen mainScreen].bounds];

    NSString * path = [[NSBundle mainBundle]pathForResource:@"ExampleApp.html" ofType:nil];
    NSURL * url = [[NSURL alloc]initFileURLWithPath:path];

    [self.webView loadRequest:[NSURLRequest requestWithURL:url]];
    self.webView.delegate = self;
    [self.view addSubview:self.webView];
    //设置能够桥接
    [WebViewJavascriptBridge enableLogging];
    //设置桥接
     self.bridge  =   [WebViewJavascriptBridge bridgeForWebView:self.webView];
    //设置代理
    [self.bridge setWebViewDelegate:self];
    //JS调用OC（testObjcCallback是和html统一的方法名字）
    [self.bridge registerHandler:@"testObjcCallback" handler:^(id data, WVJBResponseCallback responseCallback) {
        NSLog(@"按钮点击了");
        self.view.backgroundColor= [UIColor blackColor];
        responseCallback(@"按钮点击了");
    }];

}

//OC调用JS

-(void)webViewDidFinishLoad:(UIWebView *)webView{
    NSLog(@"webViewDidFinishLoad");
    [self.bridge callHandler:@"registerHandler"];
}