脚本桥不工作（KVO，零值）

Question

我目前正在为 Spotify 编写一个应用程序扩展，允许我控制播放。我将 Spotify AppleScript API 与 Objective-C 中的脚本桥结合使用。首先我想问一下，Scripting API 支持Key Value Observing吗？因为当我添加观察者时，我没有从 API 收到任何通知，而当我尝试从脚本 API 手动获取数据时，我总是得到 nil 值，为什么？我有以下代码：

    -(id)init
    {
        self=[super init];
        if(self)
        {
            spotify=[SBApplication applicationWithBundleIdentifier:@"com.spotify.client"];
            //Not sure if KVO is implemented,so I use this to get data from the API
            timer=[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(observeValueForKeyPath) userInfo:nil repeats:YES];
            if([self isSpotifyRunning])
            {
                //Useless?
                [spotify addObserver:self forKeyPath:@"currentTrack" options:NSKeyValueObservingOptionNew context:nil];
                [spotify addObserver:self forKeyPath:@"playerPosition" options:NSKeyValueObservingOptionNew context:nil];
                [spotify addObserver:self forKeyPath:@"playerState" options:NSKeyValueObservingOptionNew context:nil];
                [self.playBackSlider setTarget:self];
                [self.playBackSlider setAction:@selector(sliderDidMove:)];
                if(spotify.playerState==SpotifyEPlSPaused||spotify.playerState==SpotifyEPlSStopped)
                {
                    [self.playButton setStringValue:@"Play"];
                }
                else
                {
                    [self.playButton setStringValue:@"Stop"];
                }
            }

        }
        return self;
    }
    -(void)observeValueForKeyPath
    {
            [self.titleTextField setStringValue:spotify.currentTrack.name];
            [self.artistTextField setStringValue:spotify.currentTrack.artist];
            [self.currentPlayBackPositionTextField setStringValue:[self formatTime:spotify.playerPosition]];
            [self.remainingTimeTextField setStringValue:[self formatTime:spotify.currentTrack.duration]];
            [self.playBackSlider setMaxValue:spotify.currentTrack.duration];
            [self.playBackSlider setDoubleValue:spotify.playerPosition];
            [self.playBackSlider setDoubleValue:spotify.playerPosition];
            [self.currentPlayBackPositionTextField setStringValue:[self formatTime:spotify.playerPosition]];
        if(spotify.playerState==SpotifyEPlSPaused||spotify.playerState==SpotifyEPlSStopped)
        {
            [self.playButton setStringValue:@"Play"];
        }
        else
        {
            [self.playButton setStringValue:@"Stop"];
        }
    }
-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSString *,id> *)change context:(void *)context
{
    if([keyPath isEqualToString:@"currentTrack"])
    {
        [self.titleTextField setStringValue:spotify.currentTrack.name];
        [self.artistTextField setStringValue:spotify.currentTrack.artist];
        [self.currentPlayBackPositionTextField setStringValue:[self formatTime:spotify.playerPosition]];
        [self.remainingTimeTextField setStringValue:[self formatTime:spotify.currentTrack.duration]];
        [self.playBackSlider setMaxValue:spotify.currentTrack.duration];
        [self.playBackSlider setDoubleValue:spotify.playerPosition];
    }
    else if([keyPath isEqualToString:@"playerPosition"])
    {
        [self.playBackSlider setDoubleValue:spotify.playerPosition];
        [self.currentPlayBackPositionTextField setStringValue:[self formatTime:spotify.playerPosition]];
    }
    else if([keyPath isEqualToString:@"playerState"])
    {
        if(spotify.playerState==SpotifyEPlSPaused||spotify.playerState==SpotifyEPlSStopped)
        {
            [self.playButton setStringValue:@"Stop"];
        }
        else
        {
           [self.playButton setStringValue:@"Play"];
        }
    }
}

编辑：我为 SBApplication 对象设置了委托，但出现以下错误：

Error Domain=NSOSStatusErrorDomain Code=-600 "procNotFound: no eligible process with specified descriptor" UserInfo={ErrorNumber=-600}

这到底是什么意思？ Spotify 在创建 SBApplication 时启动，那么为什么 SBApplication 告诉我它没有找到进程？我还查看了 Spotify Bundle 中的 Info.plist，它是可编写脚本的，那么为什么它不起作用？

提前感谢您的帮助！

Answer 1

任何应用程序的 AppleScript 脚本字典——你所说的 AppleScript API——不支持 KVO。

关于在 Cocoa 应用程序中使用脚本字典忘记 ScriptingBridge。

AppleScriptObjC（在 10.6 Snow Leopard 中引入）提供了一种与 AppleScript 交互的更简单的方法。您甚至可以在同一文件中使用 AppleScript 和类似 Objective-C 的术语完全在 AppleScriptObjC 中编写 Cocoa 应用程序。

脚本桥不工作（KVO，零值）

Scripting Bridge does not work(KVO,nil values)

macos

objective-c

spotify

scripting-bridge