应用被其他程序打开时，如何切换至根视图

[hhh_hao]

- (BOOL)application:(UIApplication *)application
openURL:(NSURL *)url
sourceApplication:(NSString *)sourceApplication
annotation:(id)annotation {}

应用被其他程序打开，并回调上面的函数时， 想将当前的应用切换至主屏幕， 怎么实现？ 谢谢高手指点

[测试NULL]

- (BOOL)application:(UIApplication *)application
            openURL:(NSURL *)url
  sourceApplication:(NSString *)sourceApplication
         annotation:(id)annotation
{
    if ([sourceApplication isEqualToString:@"com.yourapp.AppName"])  //com.yourapp.AppName为调用者应用的bundle id
    {
        self.window.rootViewController = self.viewController;
        [self.window makeKeyAndVisible];
/*这两句和这个里面一样
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
    // Override point for customization after application launch.
    if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) {
        self.viewController = [[[ViewController alloc] initWithNibName:@"ViewController_iPhone" bundle:nil] autorelease];
    } else {
        self.viewController = [[[ViewController alloc] initWithNibName:@"ViewController_iPad" bundle:nil] autorelease];
    }
    self.window.rootViewController = self.viewController;
    [self.window makeKeyAndVisible];
    return YES;
}
*/
    }
    
    return YES;
}

[测试NULL]

    ALAssetsLibrary* alLibrary = [[ALAssetsLibrary alloc] init];
    NSURL *urlstr = [NSURL URLWithString:@"http://......"];
    [alLibrary assetForURL:urlstr resultBlock:^(ALAsset *asset) {
        
    } failureBlock:^(NSError *error) {
        
    }];

[hhh_hao]

引用 1 楼 wangliangffaflgh 的回复:

- (BOOL)application:(UIApplication *)application
            openURL:(NSURL *)url
  sourceApplication:(NSString *)sourceApplication
         annotation:(id)annotation
{
    if ([sourceApplication isEqualToString:@"com.yourapp.AppName"])  //com.yourapp.AppName为调用者应用的bundle id
    {
        self.window.rootViewController = self.viewController;
        [self.window makeKeyAndVisible];
/*这两句和这个里面一样
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
    // Override point for customization after application launch.
    if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) {
        self.viewController = [[[ViewController alloc] initWithNibName:@"ViewController_iPhone" bundle:nil] autorelease];
    } else {
        self.viewController = [[[ViewController alloc] initWithNibName:@"ViewController_iPad" bundle:nil] autorelease];
    }
    self.window.rootViewController = self.viewController;
    [self.window makeKeyAndVisible];
    return YES;
}
*/
    }
    
    return YES;
}

调用了没有效果

[hhh_hao]

引用 3 楼 wangliangffaflgh 的回复:

    ALAssetsLibrary* alLibrary = [[ALAssetsLibrary alloc] init];
    NSURL *urlstr = [NSURL URLWithString:@"http://......"];
    [alLibrary assetForURL:urlstr resultBlock:^(ALAsset *asset) {
        
    } failureBlock:^(NSError *error) {
        
    }];

asset的值为nil, 传过来的url 为 @“file:///private/var/mobile/.../Documents/inbox/...jpg”

[hhh_hao]

多谢楼上的回答， 如果上述的url是个媒体文件 的路径，我如果根据这个路径生成ALAsset? 或者如何获取这个媒体文件的信息