private async void OnDeferredImageRequestedHandler(DataProviderRequest request, DataPackage dp)
{
DataProviderDeferral deferral = request.GetDeferral();
try
{
StorageFile img = await PictureHandler.AsStorageFile(Items.SelectedItem.Pixels, "ToShare.jpg");
if (img != null)
{
List <IStorageFile> imageItems = new List <IStorageFile>
{
img
};
dp.SetStorageItems(imageItems);
RandomAccessStreamReference imageStreamRef = RandomAccessStreamReference.CreateFromFile(img);
dp.Properties.Thumbnail = imageStreamRef;
dp.SetBitmap(imageStreamRef);
}
}
catch (Exception e)
{
throw e;
}
deferral.Complete();
}
private async void OnDeferredImageRequestedHandler(DataProviderRequest providerRequest, StorageFile imageFile)
{
// In this delegate we provide updated Bitmap data using delayed rendering.
if (imageFile != null)
{
// If the delegate is calling any asynchronous operations it needs to acquire the deferral first. This lets the
// system know that you are performing some operations that might take a little longer and that the call to
// SetData could happen after the delegate returns. Once you acquired the deferral object you must call Complete
// on it after your final call to SetData.
DataProviderDeferral deferral = providerRequest.GetDeferral();
InMemoryRandomAccessStream inMemoryStream = new InMemoryRandomAccessStream();
// Make sure to always call Complete when done with the deferral.
try
{
// Decode the image and re-encode it at 50% width and height.
IRandomAccessStream imageStream = await imageFile.OpenAsync(FileAccessMode.Read);
BitmapDecoder imageDecoder = await BitmapDecoder.CreateAsync(imageStream);
BitmapEncoder imageEncoder = await BitmapEncoder.CreateForTranscodingAsync(inMemoryStream, imageDecoder);
imageEncoder.BitmapTransform.ScaledWidth = (uint)(imageDecoder.OrientedPixelWidth * 0.5);
imageEncoder.BitmapTransform.ScaledHeight = (uint)(imageDecoder.OrientedPixelHeight * 0.5);
await imageEncoder.FlushAsync();
providerRequest.SetData(RandomAccessStreamReference.CreateFromStream(inMemoryStream));
}
finally
{
deferral.Complete();
}
}
}
// 用户点击了分享目标后会调用此方法
private async void OnDeferredImageRequestedHandler(DataProviderRequest providerRequest, StorageFile imageFile)
{
// 获取 DataProviderDeferral，以开始异步处理
DataProviderDeferral deferral = providerRequest.GetDeferral();
InMemoryRandomAccessStream inMemoryStream = new InMemoryRandomAccessStream();
try
{
// 将用户选中的图片缩小一倍，然后再分享
IRandomAccessStream imageStream = await imageFile.OpenAsync(FileAccessMode.Read);
BitmapDecoder imageDecoder = await BitmapDecoder.CreateAsync(imageStream);
BitmapEncoder imageEncoder = await BitmapEncoder.CreateForTranscodingAsync(inMemoryStream, imageDecoder);
imageEncoder.BitmapTransform.ScaledWidth = (uint)(imageDecoder.OrientedPixelWidth * 0.5);
imageEncoder.BitmapTransform.ScaledHeight = (uint)(imageDecoder.OrientedPixelHeight * 0.5);
await imageEncoder.FlushAsync();
// 停 3 秒，以模拟长时间任务
await Task.Delay(3000);
providerRequest.SetData(RandomAccessStreamReference.CreateFromStream(inMemoryStream));
}
finally
{
// 完成异步操作
deferral.Complete();
}
}
private async void ProvideData(DataProviderRequest request)
{
DataProviderDeferral deferral = request.GetDeferral();
var stream = new InMemoryRandomAccessStream();
await Graph.SaveImageAsync(stream);
request.SetData(RandomAccessStreamReference.CreateFromStream(stream));
deferral.Complete();
}
//<SnippetShareFileFunction_CS>
//<SnippetShareFileFunction>
async void OnDeferredImageRequestedHandler(DataProviderRequest request)
{
// Here we provide updated Bitmap data using delayed rendering
if (this.imageStream != null)
{
//<SnippetGetDefferal_CS>
//<SnippetGetDefferal>
DataProviderDeferral deferral = request.GetDeferral();
//</SnippetGetDefferal>
//</SnippetGetDefferal_CS>
try
{
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));
}
catch (Exception ex)
{
// Handle the exception
}
finally
{
deferral.Complete();
}
}
}
// <SnippetShareFileFunction_CS>
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();
}
}
private void OnDeferredImageRequestedHandler(DataProviderRequest request)
{
if (_url != null)
{
// If the delegate is calling any asynchronous operations it needs to acquire
// the deferral first. This lets the system know that you are performing some
// operations that might take a little longer and that the call to SetData
// could happen after the delegate returns. Once you acquired the deferral object
// you must call Complete on it after your final call to SetData.
DataProviderDeferral deferral = request.GetDeferral();
// Make sure to always call Complete when finished with the deferral.
try
{
request.SetData(_url);
}
finally
{
deferral.Complete();
}
}
}
private async void OnDeferredImageRequestedHandler(DataProviderRequest request)
{
// Request deferral to wait for async calls
DataProviderDeferral deferral = request.GetDeferral();
// XAML objects can only be accessed on the UI thread, and the call may come in on a background thread
await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, async() =>
{
try
{
RenderTargetBitmap renderTargetBitmap = new RenderTargetBitmap();
InMemoryRandomAccessStream stream = new InMemoryRandomAccessStream();
// Render to an image at the current system scale and retrieve pixel contents
await renderTargetBitmap.RenderAsync(collageCanvas);
var pixelBuffer = await renderTargetBitmap.GetPixelsAsync();
// Encode image to an in-memory stream
var encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.PngEncoderId, stream);
encoder.SetPixelData(
BitmapPixelFormat.Bgra8,
BitmapAlphaMode.Ignore,
(uint)renderTargetBitmap.PixelWidth,
(uint)renderTargetBitmap.PixelHeight,
DisplayInformation.GetForCurrentView().LogicalDpi,
DisplayInformation.GetForCurrentView().LogicalDpi,
pixelBuffer.ToArray());
await encoder.FlushAsync();
// Set content of the DataProviderRequest to the encoded image in memory
request.SetData(RandomAccessStreamReference.CreateFromStream(stream));
}
finally
{
deferral.Complete();
}
});
}
