Swift 和 ScriptingBridge.framework

Question

在我的 Swift 项目中，我需要通过 ScriptingBridge 框架与 iTunes 进行通信。根据Apple文档，我使用sdef /Applications/iTunes.app | sdp -fh --basename iTunes创建iTunes.h文件，然后将ScriptingBridge.framework链接到项目并使用#import "iTunes.h"创建AppName-Bridging-Header.h文件。

但是当我尝试获取任何 iTunes 应用程序属性时，例如

var iTunesApp: iTunesApplication? = SBApplication.applicationWithBundleIdentifier("com.apple.iTunes") as? iTunesApplication
let currentTrack: iTunesTrack? = iTunesApp?.currentTrack

我得到类似的链接器错误

Undefined symbols for architecture x86_64:
"_OBJC_CLASS_$_iTunesApplication", referenced from:
  __TFC5NowP_14iTunesWorker21fetchCurrentTrackInfofS0_FT_T_ in iTunesWorker.o
  __TFC5NowP_14iTunesWorkercfMS0_FT_S0_ in iTunesWorker.o
  _get_field_types_iTunesWorker in iTunesWorker.o
"_OBJC_CLASS_$_iTunesTrack", referenced from:
  __TFC5NowP_14iTunesWorker21fetchCurrentTrackInfofS0_FT_T_ in iTunesWorker.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

我使用 Xcode 6 beta 4。有什么想法吗？

Answer 1

检查一下，它使用 Swift 并且可以正常工作（我测试过）

https://gist.github.com/bjhomer/fe8b3b05388b71ba0ab9

import ScriptingBridge

@objc protocol iTunesTrack {
    optional var name: String {get}
    optional var album: String {get}
}

@objc protocol iTunesApplication {
    optional var soundVolume: Int {get}
    optional var currentTrack: iTunesTrack? {get}
}

extension SBApplication : iTunesApplication {}

let app: iTunesApplication = SBApplication(bundleIdentifier: "com.apple.iTunes")

// Because these are all optional properties (to avoid providing an implementation), we have 
// to use '!' to indicate we know the implementation exists.
let track: iTunesTrack? = app.currentTrack!
let album = track?.album!
let trackName = track?.name!


println("Current track: \(trackName) - \(album)")

Answer 2

当我使用valueForKey(key: String?) 获取属性时，我发现链接器错误消失了。所以这个问题看起来像是 Swift 测试版的不完美。