我有同樣的問題,但發現在C#中呈現PNG的這個例子。我現在發現這個對https://social.msdn.microsoft.com/Forums/en-US/43295c90-43e8-4b08-8a25-958a1c3d0a0b/explanation-on-windowsuixamlmediaxamlrenderingbackgroundtask?forum=WindowsPhonePreviewSDK
using System;
using System.Threading.Tasks;
using Windows.ApplicationModel.Background;
using Windows.Storage.Streams;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Markup;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Media.Imaging;
using Windows.Graphics.Imaging;
using Windows.UI.Notifications;
using Windows.Data.Xml.Dom;
namespace BackgroundTask
{
public sealed class AppTileUpdater : XamlRenderingBackgroundTask
{
protected override void OnRun(Windows.ApplicationModel.Background.IBackgroundTaskInstance taskInstance)
{
BackgroundTaskDeferral _deferral = taskInstance.GetDeferral();
System.Diagnostics.Debug.WriteLine("OnRun called!");
UpdateTileAsync(_deferral);
}
private async Task<string> ReadFile()
{
var folder = await Windows.ApplicationModel.Package.Current.InstalledLocation.GetFolderAsync("Assets");
var file = await folder.GetFileAsync("customTile.xml");
string szCustomTileXML = await Windows.Storage.FileIO.ReadTextAsync(file);
return szCustomTileXML;
}
private async void UpdateTileAsync(BackgroundTaskDeferral deferral)
{
var folder = await Windows.ApplicationModel.Package.Current.InstalledLocation.GetFolderAsync("Assets");
var file = await folder.GetFileAsync("customTile.xml");
string szCustomTileXML = await Windows.Storage.FileIO.ReadTextAsync(file);
Border tile = XamlReader.Load(szCustomTileXML) as Border;
if (null != tile)
{
tile.Background = new SolidColorBrush(Windows.UI.Colors.Orange);
Grid grid = tile.Child as Grid;
TextBlock text = grid.FindName("Timestamp") as TextBlock;
text.Text = DateTime.Now.ToString("hh:mm:ss");
text = grid.FindName("TimeZone") as TextBlock;
text.Text = TimeZoneInfo.Local.DisplayName;
Image logo = grid.FindName("LogoImage") as Image;
var img = new BitmapImage() { CreateOptions = BitmapCreateOptions.None };
img.UriSource = new Uri("ms-appx:///Assets/acorn.png");
RenderTargetBitmap rtb = new RenderTargetBitmap();
await rtb.RenderAsync(tile, 150, 150);
IBuffer pixels = await rtb.GetPixelsAsync();
DataReader dReader = Windows.Storage.Streams.DataReader.FromBuffer(pixels);
byte[] data = new byte[pixels.Length];
dReader.ReadBytes(data);
var outputFile = await Windows.ApplicationModel.Package.Current.InstalledLocation.CreateFileAsync("UpdatedLiveTile.png", Windows.Storage.CreationCollisionOption.ReplaceExisting);
var outputStream = await outputFile.OpenAsync(Windows.Storage.FileAccessMode.ReadWrite);
BitmapEncoder enc = await BitmapEncoder.CreateAsync(BitmapEncoder.PngEncoderId, outputStream);
enc.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Premultiplied, (uint)rtb.PixelWidth, (uint)rtb.PixelHeight, 96,96, data);
await enc.FlushAsync();
}
var TileMgr = TileUpdateManager.CreateTileUpdaterForApplication();
TileMgr.Clear();
var tileTemplate = TileUpdateManager.GetTemplateContent(TileTemplateType.TileSquare150x150Image);
var tileImageAttributes = tileTemplate.GetElementsByTagName("image");
XmlElement tmp = tileImageAttributes[0] as XmlElement;
tmp.SetAttribute("src", "UpdatedLiveTile.png");
var notification = new TileNotification(tileTemplate);
TileMgr.Update(notification);
deferral.Complete();
}
public void Run(IBackgroundTaskInstance taskInstance)
{
System.Diagnostics.Debug.WriteLine("Run called!");
OnRun(taskInstance);
}
}
}
只需在C#中執行他們在C++示例中的操作。 :)我測試了它,它似乎工作正常。我不認爲內存或CPU時間是一個問題(當我測試它時,它們不是)。 – yasen