IOS Webview JS交互之事件拦截获取

   最近项目中用到了webvVew，webView加载的网页中有两个按钮，要在app里面响应这两个按钮的点击事件，并接受JS传过来的参数。

  ios7 的时候，出来了一个新的类库叫JavaScriptCore.framework

- (void)setupJsContent
{
    //获取当前JS环境
    _content = [_webView valueForKeyPath:@"documentView.webView.mainFrame.javaScriptContext"];
    // 打印异常
    _content.exceptionHandler =
    ^(JSContext *context, JSValue *exceptionValue)
    {
        context.exception = exceptionValue;
        LogInfo(@"%@", exceptionValue);
    };
    //获取JS事件
    WS(bself);
    _content[@"showtag"] = ^(int num,NSString *tag){
        LogInfo(@"num = %d   \n tag = %@",num,tag);
        if (num == 1) {     //查看项目所在地
            //获取经纬度
            NSArray *locationArray = [tag componentsSeparatedByString:@","];
            ProjectLocationViewController *locationCtrl = [[ProjectLocationViewController alloc]init];
            locationCtrl.longitude = [locationArray[0] floatValue];
            locationCtrl.latitude = [locationArray[1] floatValue];
            [bself.navigationController pushViewController:locationCtrl animated:YES];
        }else if(num == 2){
            UIAlertView *alter = [[UIAlertView alloc]initWithTitle:@"标题" message:@"内容" delegate:nil cancelButtonTitle:@"取消" otherButtonTitles:@"确定", nil];
            alter.alertViewStyle = UIAlertViewStylePlainTextInput;
            
            [alter show];
        }
    };
}