iphone - 如何使用 MPMoviePlayerController 播放视频？

Question

我正在使用以下代码使用 MPMoviePlayerController 播放视频，但视频未播放。谁能告诉我为什么？

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:@"/one.mp4"];

NSString *mediaPath = [[[NSBundle mainBundle]resourcePath] stringByAppendingPathComponent:filePath];

    MPMoviePlayerController *moviePlayer = [[MPMoviePlayerController alloc] initWithContentURL:[NSURL fileURLWithPath:mediaPath]];

    [[moviePlayer view] setFrame:[[self view] bounds]];
    [[self view] addSubview: [moviePlayer view]];


    moviePlayer.scalingMode = MPMovieScalingModeAspectFit;

    [moviePlayer play];

Answer 1

这很奇怪，但如果您将 MPMoviePlayerController 设为属性而不是局部变量，它似乎工作正常。似乎在幕后发生了什么。我认为这与ARC有关。你在使用 ARC 吗？

这也是您过度附加路径的问题:

// You've already got the full path to the documents directory here.
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:@"/one.mp4"];
// Now you're appending the full path to the documents directory to your bundle path
NSString *mediaPath = [[[NSBundle mainBundle]resourcePath] stringByAppendingPathComponent:filePath];

当我在模拟器中运行你的代码时，路径如下所示:

/Users/mlong/Library/Application Support/iPhone Simulator/5.1/Applications/8CFB9B94-BD6A-442C-A525-573FE343506D/VidoePlayer.app/Users/mlong/Library/Application Support/iPhone Simulator/5.1/Applications/8CFB9B94-BD6A-442C-A525-573FE343506D/Documents/one.mp4

应该是这样的:

/Users/mlong/Library/Application Support/iPhone Simulator/5.1/Applications/8CFB9B94-BD6A-442C-A525-573FE343506D/Documents/one.mp4

所以只需删除这一行:

NSString *mediaPath = [[[NSBundle mainBundle]resourcePath] stringByAppendingPathComponent:filePath];

然后将您的播放器实例化为:

_moviePlayer = [[MPMoviePlayerController alloc] initWithContentURL:[NSURL fileURLWithPath:filePath]];

[[_moviePlayer view] setFrame:[[self view] bounds]];
[[self view] addSubview: [_moviePlayer view]];

_moviePlayer.scalingMode = MPMovieScalingModeAspectFit;

[_moviePlayer play];

因此您应该将 MPMoviePlayerController 添加为包含 View Controller 的属性。