webview_capturepreviewtostreamasync_1169189879.md

-api-id	-api-type
M:Windows.UI.Xaml.Controls.WebView.CapturePreviewToStreamAsync(Windows.Storage.Streams.IRandomAccessStream)	winrt method

Windows.UI.Xaml.Controls.WebView.CapturePreviewToStreamAsync

-description

Creates an image of the current WebView contents and writes it to the specified stream.

-parameters

-param stream

The stream to write the image to.

-returns

An asynchronous action to await the capture operation.

-remarks

-examples

This example shows how to use this method to create a thumbnail image of the current content. For the complete example, see the WebView control sample.

private async void bookmarkBtn_Click(object sender, RoutedEventArgs e)
{
    InMemoryRandomAccessStream ms = new InMemoryRandomAccessStream();
    await webView8.CapturePreviewToStreamAsync(ms);
            
    // Create a small thumbnail.
    int longlength = 180, width = 0, height = 0;
    double srcwidth = webView8.ActualWidth, srcheight = webView8.ActualHeight;
    double factor = srcwidth / srcheight;
    if (factor < 1)
    {
        height = longlength;
        width = (int)(longlength * factor);
    }
    else
    {
        width = longlength;
        height = (int)(longlength / factor);
    }
    BitmapSource small = await resize(width, height, ms);
            
    BookmarkItem item = new BookmarkItem();
    item.Title = webView8.DocumentTitle;
    item.PageUrl = webView8.Source;
    item.Preview = small;

    bookmarks.Add(item);
}

-see-also

XAML WebView control sample