這個系統對象指針代碼是否可以在Swift中使用？

Question

我被指出這個objc片段from WWDC 14，但我在一個Swift項目上工作。

CMIOObjectPropertyAddress prop = { 
    kCMIOHardwarePropertyAllowScreenCaptureDevices, 
    kCMIOObjectPropertyScopeGlobal, 
    kCMIOObjectPropertyElementMaster 
}; 
UInt32      allow = 1; 

CMIOObjectSetPropertyData(kCMIOObjectSystemObject, &prop, 0, NULL, sizeof(allow), &allow); 

我又試圖改寫斯威夫特：

var prop : CMIOObjectPropertyAddress { 
    kCMIOHardwarePropertyAllowScreenCaptureDevices 
    kCMIOObjectPropertyScopeGlobal 
    kCMIOObjectPropertyElementMaster 
} 

var allow:UInt32 = 1 
CMIOObjectSetPropertyData(kCMIOObjectSystemObject, &prop, 0, nil, sizeof(UInt32), &allow) 

但它甚至不進行驗證。我不知道如何翻譯CMIOObjectPropertyAddress結構。 Xcode中說

/Users/mortenjust/Dropbox/hack/learning/screenrec/screenrec/deleteme.swift:32:61： 不能分配給GET-唯一的財產 '託'

Answer 1

AC結構翻譯爲Swift結構。使用隱按成員初始化：

var prop = CMIOObjectPropertyAddress(
     mSelector: UInt32(kCMIOHardwarePropertyAllowScreenCaptureDevices), 
     mScope: UInt32(kCMIOObjectPropertyScopeGlobal), 
     mElement: UInt32(kCMIOObjectPropertyElementMaster)) 

涼爽的部分是，當你鍵入CMIOObjectPropertyAddress(，代碼完成給你休息。

Answer 2

你是對的，剛剛得到它跑在這一秒。原來，我也必須糾正一些類型。這裏是完整的翻譯：

 var prop = CMIOObjectPropertyAddress(
     mSelector: CMIOObjectPropertySelector(kCMIOHardwarePropertyAllowScreenCaptureDevices), 
     mScope: CMIOObjectPropertyScope(kCMIOObjectPropertyScopeGlobal), 
     mElement: CMIOObjectPropertyElement(kCMIOObjectPropertyElementMaster)) 

    var allow : UInt32 = 1 
    var dataSize : UInt32 = 4 
    var zero : UInt32 = 0 
    CMIOObjectSetPropertyData(CMIOObjectID(kCMIOObjectSystemObject), &prop, zero, nil, dataSize, &allow) 

    var session = AVCaptureSession() 
    session.sessionPreset = AVCaptureSessionPresetHigh 

    var devices = AVCaptureDevice.devices() 
    for device in AVCaptureDevice.devices() { 
     println(device) 
    }