rendertargetbitmap

问题 I have the following code: LinearGradientBrush linGrBrush = new LinearGradientBrush(); linGrBrush.StartPoint = new Point(0,0); linGrBrush.EndPoint = new Point(1, 0); linGrBrush.GradientStops.Add(new GradientStop(Colors.Red, 0.0)); linGrBrush.GradientStops.Add(new GradientStop(Colors.Yellow, 0.5)); linGrBrush.GradientStops.Add(new GradientStop(Colors.White, 1.0)); Rectangle rect = new Rectangle(); rect.Width = 1000; rect.Height = 1; rect.Fill = linGrBrush; rect.Arrange(new Rect(0, 0, 1, 1000))

问题 I'm trying to create a bitmap image, and have the following code: RenderTargetBitmap renderTargetBitmap = new RenderTargetBitmap(); await renderTargetBitmap.RenderAsync(uielement); IBuffer pixels = await renderTargetBitmap.GetPixelsAsync(); . . . var pixelArray = pixels.ToArray(); In order to get a ToArray() extension, I came across this question. So I added: using System.Runtime.InteropServices.WindowsRuntime; // For ToArray To my code. However, when I run, I get the following error:

问题 I am trying to implement a screenshot functionality in a WinRT app that shows Video via a MediaElement. I have the following code, it saves a screenshot that's the size of the MediaElement but the image is empty (completely black). Tried with various types of Media files. If I do a Win Key + Vol Down on Surface RT, the screen shot includes the Media frame content, but if I use the following code, it's blackness all around :( private async Task SaveCurrentFrame() { RenderTargetBitmap

问题 RenderTargetBitmap removes downgrades a RichtextBox's TextRenderingMode to GreyScale. So a captured PNG looks poor quality and doesnt match the WPF control If I use WINDOWS ALT+PRINT SCREEN, the text is captured perfectly. So how can I render the text control to the same quality as ALT+PRINT SCREEN. Any advice would seriously be appreciated All the best 回答1: You can use the same technique to render your window into the bitmap as windows using when taking a screen shot with Alt + Print Screen

问题 I'm using SVG# (http://sharpvectors.codeplex.com/), to batch convert SVG files to other formats. The SVG images being converted are black line drawings with no background. I've little experience with WPF or the System.Windows.Media namespace, so please excuse me if this is a basic question. I'm using a modified version of the ImageSvgConverter from SVG#, which accepts a System.Windows.Media.Drawing object, which is then converted using a System.Windows.Media encoder ( BmpBitmapEncoder ,

问题 am trying to render an image with RenderTargetBitmap every time i create an instance from RenderTargetBitmap to render image the memory increased and when am done the memory never released and this is the code : RenderTargetBitmap rtb = new RenderTargetBitmap((int)(renderWidth * dpiX / 96.0), (int)(renderHeight * dpiY / 96.0), dpiX, dpiY, PixelFormats.Pbgra32); DrawingVisual dv = new DrawingVisual(); using (DrawingContext ctx = dv.RenderOpen()) { VisualBrush vb = new VisualBrush(target); ctx

问题 After the RenderTargetBitmap is much too slow. I tried a different approach. Unfortunately my attempt was not successful. Hopefully some of you guys can figure out why this code is not working. var myPopup = new Popup(); var child = new Grid() { Background = new VisualBrush(myVisual)}; myPopup.StaysOpen = false; myPopup.Child = child; myPopup.IsOpen = false; myPopup.Opened += (sender, args) => { var source = ((HwndSource)PresentationSource.FromVisual(myPopup.Child)); var image = new Bitmap

问题 I want to use RenderTargetBitmap to render a UserControl to a bitmap without having to write the XAML for it. When I do this I get a blank image, am I missing a crucial step? ValTool.Controls.VideoFisheyeOverlayControl vfoc = new Controls.VideoFisheyeOverlayControl(); vfoc.Width = (int)this.VideoContainer.ActualWidth; vfoc.Height = (int)this.VideoContainer.ActualHeight; vfoc.FieldsOfView=this.FieldsOfView; vfoc.CountLines = this.CountLines; vfoc.UpdateLayout(); vfoc.InvalidateVisual();

问题 I'm trying to save an UIElement created programmatically in a JPG/PNG/BMP image in a Windows Phone 8.1 (C#) application. I'm using the class RenderTargetBitmap using the method RenderAsync() but it only works with UI elements created in the XAML code. When I use it on UI elements created directly in C# I have this exception: "System.ArgumentException (Value does not fall within the expected range.)" Am I doing something wrong or this class doesn't allow rendering of UIElement(s) created

问题 I have a RenderTargetBitmap , I need to convert it to BitmapImage . Please check the code below. RenderTargetBitmap bitMap = getRenderTargetBitmap(); Image image = new Image();// This is a Image image.Source = bitMap; In the above code I have used Image.Now I need to use a BitmapImage. How can I do this? RenderTargetBitmap bitMap = getRenderTargetBitmap(); BitmapImage image = new BitmapImage();// This is a BitmapImage // how to set bitMap as source of BitmapImage ? 回答1: Although it doesn't