App Extensions 打开 app

App Extensions里不能直接调用openurl的方式去打开app，sdk提供了一种方法:

// Asks the host to open an URL on the extension's behalf- (void)openURL:(NSURL *)URL completionHandler:(void (^ __nullable)(BOOL success))completionHandler;

但是这种方法目前只能适用于today extension（其他的extension暂时不可用）。

通过网上查找资料，目前搜集到两个方法：

第一种，sdk版本要8.3以上（包括8.3，9.2测试还可以用）

    // Prepare the URL request    // this will use the custom url scheme of your app    // and the paths to the photos you want to share:    NSString * urlString = [ NSString stringWithFormat: @"%@://%@", APP_SHARE_URL_SCHEME, ( NULL == invokeArgs ? @"" : invokeArgs ) ];    NSURL * url = [ NSURL URLWithString: urlString ];     NSString *className = @"UIApplication";    if ( NSClassFromString( className ) )    {        id object = [ NSClassFromString( className ) performSelector: @selector( sharedApplication ) ];        [ object performSelector: @selector( openURL: ) withObject: url ];    }

第二种，sdk版本低于8.3的

        // openURL doesn't work for any extension, but the Today one,        // so we'll use a workaround:        // 1. Instantiate a UIWebView that's so tiny it won't show on the screen:        UIWebView * webView = [ [ UIWebView alloc ] initWithFrame: CGRectMake( 0, 0, 0, 0 ) ];         // 2. Prepare the URL request for the UIWebView:        // this will use the custom url scheme of your app        // and the paths to the photos you want to share:        NSString * urlString = [ NSString stringWithFormat: @"%@://%@", APP_SHARE_URL_SCHEME, ( NULL == invokeArgs ? @"" : invokeArgs ) ];        NSURL * url = [ NSURL URLWithString: urlString ];        NSURLRequest * request = [ NSURLRequest requestWithURL: url ];         // 3. Now get the UIWebView to load the request, which will launch the app:        [ webView loadRequest: request ];        [ self.view addSubview: webView ];         // 4. And finally, say bye to the UIWebView.        // The delay is important here, otherwise the UIWebView won't have time        // to invoke your app before it's dismissed:        [ webView performSelector: @selector( removeFromSuperview ) withObject: NULL afterDelay: 2.0 ];

以上主要方法来自http://easynativeextensions.com/how-to-launch-your-app-from-the-ios-8-share-menu/ 这篇文章