在 WatchKit OS2 中播放音频文件

Question

从手机发送 MP3：

NSArray *pathArray = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES);  
NSString *documentsDirectory = [pathArray objectAtIndex:0];  

NSString *yourSoundPath = [documentsDirectory stringByAppendingPathComponent:@"MyMusic.mp3"];  
NSURL *url = [NSURL fileURLWithPath:yourSoundPath isDirectory:NO];  
[self.session transferFile:url metadata:nil];  

我如何尝试在手表上接收和播放文件：

-(void)session:(WCSession *)session didReceiveFile:(WCSessionFile *)file {  
    dispatch_async(dispatch_get_main_queue(), ^{  

        NSLog(@"URL%@" , file.fileURL.filePathURL);  

        NSDictionary *options = @{  
                                  WKMediaPlayerControllerOptionsAutoplayKey : @YES  
                                  };  

        [self presentMediaPlayerControllerWithURL:file.fileURL.filePathURL options:options completion:^(BOOL didPlayToEnd, NSTimeInterval endTime, NSError * __nullable error) {  
            if (!didPlayToEnd) {  
                NSLog(@"The player did not play all the way to the end. The player only played until time - %.2f.", endTime);  
            }  

            if (error) {  
                NSLog(@"There was an error with playback: %@.", error);  
            }  
        }];  
    });  
} 

这是文件的 URL：

file:///var/mobile/Containers/Data/PluginKitPlugin/-------/Documents/Inbox/com.apple.watchconnectivity/------/Files/----/我的音乐.mp3

这是错误：

播放出错：Error Domain=com.apple.watchkit.errors Code=4“在此服务器上找不到请求的 URL。” UserInfo={NSUnderlyingError=0x16d4fa10 {Error Domain=NSPOSIXErrorDomain Code=2 "No such file or directory"}, NSLocalizedDescription=在此服务器上找不到请求的 URL。}。

如何在 watchOS 2 中播放这个文件？

Answer 1

要使手表应用能够播放音频文件，您必须将其移动到共享应用组容器中。

您需要在WatchKit 扩展和WatchKit 应用之间启用共享应用组。

如果您没有将文件放在共享容器中，则预计音频播放会失败。在移动文件之前，您也不应该从回调队列中分派出去，因为 WCSession 将在回调返回时删除文件。

这里有一个 tutorial 解释了如何做到这一点，还有一个来自 Apple 的 some information 关于这个主题。

编辑：添加示例

一旦您为 WatchKit 应用和扩展启用了应用组容器，这样的事情应该可以工作：

- (void)session:(WCSession * __nonnull)session didReceiveFile:(WCSessionFile * __nonnull)file
{
    NSLog(@"received file %@, metadata: %@", file, file.metadata);

    NSFileManager *fm = [NSFileManager defaultManager];
    NSError *error = nil;
    NSURL *containerURL = [fm containerURLForSecurityApplicationGroupIdentifier:@"<YOUR APP GROUP HERE>"];
    NSString *documentsPath = [containerURL path];
    NSString *dateString = [[[NSDate date] description] stringByAppendingString:@"-"];
    NSString *fileNameWithDate = [dateString stringByAppendingString:file.fileURL.lastPathComponent];
    documentsPath = [documentsPath stringByAppendingPathComponent:fileNameWithDate];
    if ([fm moveItemAtPath:[file.fileURL.path stringByExpandingTildeInPath] toPath:documentsPath error:&error]) {
        if ([fm fileExistsAtPath:documentsPath isDirectory:nil]) {
            NSLog(@"moved file %@ to %@", file.fileURL.path, documentsPath);
            dispatch_async(dispatch_get_main_queue(), ^{
                NSDictionary *options = @{ WKMediaPlayerControllerOptionsAutoplayKey : @YES };
                [self presentMediaPlayerControllerWithURL:[NSURL fileURLWithPath:documentsPath] options:options completion:^(BOOL didPlayToEnd, NSTimeInterval endTime, NSError * __nullable playAudioError) {
                    if (!didPlayToEnd) {
                        NSLog(@"The player did not play all the way to the end. The player only played until time - %.2f.", endTime);
                    }

                    if (playAudioError) {
                        NSLog(@"There was an error with playback: %@.", playAudioError);
                    }
                }];
             });


        } else {
            NSLog(@"failed to confirm move of file %@ to %@ (%@)", file.fileURL.path, documentsPath, error);
        }
    } else {
        NSLog(@"failed to move file %@ to %@ (%@)", file.fileURL.path, documentsPath, error);
    }
}