初始化 ProximityDevice 时出现 UnauthorizedAccessException (Windows Phone)

Question

我想在我的应用程序中使用ProximityDevice。如果我将其声明为字段或在构造函数中，如下所示：

public partial class MainPage : PhoneApplicationPage {
    // Constructor
    public ProximityDevice device;
    public MainPage() {
        InitializeComponent();
        device = ProximityDevice.GetDefault(); 
    }
}

或者这个：

public partial class MainPage : PhoneApplicationPage {
    // Constructor

    public MainPage() {
        InitializeComponent();
       public ProximityDevice device = ProximityDevice.GetDefault(); 
    }
}

我明白了

A first chance exception of type 'System.UnauthorizedAccessException' occurred in SecurityClient.DLL
A first chance exception of type 'System.Reflection.TargetInvocationException' occurred in mscorlib.ni.dll
A first chance exception of type 'System.Reflection.TargetInvocationException' occurred in Microsoft.Phone.ni.dll

如果我将其声明为静态代码不会导致任何问题：

 public partial class MainPage : PhoneApplicationPage {
        // Constructor
        public static  ProximityDevice device = ProximityDevice.GetDefault();
        public MainPage() {
            InitializeComponent();       
        }
    }

如何解决这个问题？

Answer 1

确保您已将 ID_CAP_PROXIMITY 功能添加到您的应用程序清单中。