VideoDeviceController.TryAcquireExclusiveControl 方法

public:
 virtual bool TryAcquireExclusiveControl(Platform::String ^ deviceId, MediaCaptureDeviceExclusiveControlReleaseMode mode) = TryAcquireExclusiveControl;

bool TryAcquireExclusiveControl(winrt::hstring const& deviceId, MediaCaptureDeviceExclusiveControlReleaseMode const& mode);

public bool TryAcquireExclusiveControl(string deviceId, MediaCaptureDeviceExclusiveControlReleaseMode mode);

function tryAcquireExclusiveControl(deviceId, mode)

Public Function TryAcquireExclusiveControl (deviceId As String, mode As MediaCaptureDeviceExclusiveControlReleaseMode) As Boolean

參數

傳回

True 是表示 如果取得相機的獨佔控制;否則為 false。

Windows 需求

範例

此範例示範在獨佔控制項中使用相機的應用程式如何確保相機組態是在擷取開始之前設定，而且不會由另一個應用程式在前取得獨佔控制項鎖定來變更此相機的存取權。

private static System.Threading.ManualResetEvent _exclusiveLockAcquire = new System.Threading.ManualResetEvent(false);

public static void RecordVideo()
{
    MediaCapture mediacapture = new MediaCapture();
    await mediacapture.InitializeAsync();

    mediacapture.CaptureDeviceExclusiveControlStatusChanged += 
Mediacapture_CaptureDeviceExclusiveControlStatusChanged;

    _exclusiveLockAcquire.WaitOne();
    _exclusiveLockAcquire.Reset();

    // configure camera - blocking other application from changing the configuration.

    // record video
}

private static void Mediacapture_CaptureDeviceExclusiveControlStatusChanged(MediaCapture sender, MediaCaptureDeviceExclusiveControlStatusChangedEventArgs args)
{
    if (args.Status == MediaCaptureDeviceExclusiveControlStatus.ExclusiveControlAvailable)
    {
        if (sender.VideoDeviceController().TryAcquireExclusiveControl(
            args.DeviceId(),     
            MediaCaptureDeviceExclusiveControlReleaseMode.OnAllStreamsStopped))
        {
            _exclusiveLockAcquire.Set();
        }
    }
}

適用於