DataProviderRequest.GetDeferral 方法

定義

命名空間:

Windows.ApplicationModel.DataTransfer

會傳回 DataProviderDeferral 物件。

public:
 virtual DataProviderDeferral ^ GetDeferral() = GetDeferral;

DataProviderDeferral GetDeferral();

public DataProviderDeferral GetDeferral();

function getDeferral()

Public Function GetDeferral () As DataProviderDeferral

傳回

DataProviderDeferral

資料提供者延遲物件。

範例

async void OnDeferredImageRequestedHandler(DataProviderRequest request)
{
    // Provide updated bitmap data using delayed rendering.
    if (this.imageStream != null)
    {
        DataProviderDeferral deferral = request.GetDeferral();
        InMemoryRandomAccessStream inMemoryStream = new InMemoryRandomAccessStream();

        // Decode the image.
        BitmapDecoder imageDecoder = await BitmapDecoder.CreateAsync(this.imageStream);

        // Re-encode the image at 50% width and height.
        BitmapEncoder imageEncoder = await BitmapEncoder.CreateForTranscodingAsync(inMemoryStream, imageDecoder);
        imageEncoder.BitmapTransform.ScaledWidth = (uint)(imageDecoder.OrientedPixelHeight * 0.5);
        imageEncoder.BitmapTransform.ScaledHeight = (uint)(imageDecoder.OrientedPixelHeight * 0.5);
        await imageEncoder.FlushAsync();

        request.SetData(RandomAccessStreamReference.CreateFromStream(inMemoryStream));
        deferral.Complete();
    }
}

備註

若要深入瞭解，請參閱 如何以非同步方式產生要求的資料。