gdi+

问题 I get as Generic GDI Error with the following code. Usually it complies and executes just fine but sometimes fails with a Generic GDI+ Error. Is there some way to solve the issue, or a way to take a screenshot without using inter-op? Public Function CopyImageFromScreen(region as Int32Rect) As BitmapSource Dim img As New System.Drawing.Bitmap(region.Width, region.Height) Dim gfx As System.Drawing.Graphics = System.Drawing.Graphics.FromImage(img) gfx.CopyFromScreen(region.X, region.Y, 0, 0, New

问题 I'm building an Image upload tool that resizes an image to fit a fixed size but it's adding a black background instead of a transparent one to the filler space around the image. I've read that the Bitmap needs to be set to a PixelFormat with an Alpha layer and that I can set the Graphics clear colour to transparent but I'm still getting the same problem. My images are mostly jpegs. Here is the code: private void ResizeImage(Image Original, Int32 newWidth, Int32 newHeight, String pathToSave) {

问题 I have a Circle and a Line control. Circle control's OnPaint draws a circle and Line control's one draws a line. These two controls are contained in another control (DrawingControl). I need to put a Line over a Circle, but Circle's background deletes the Line. I tried enabling transparency and overriding Circle's OnPaintBackground method, but it doesn't seem to work. Do you have any ideas? Thanks. 回答1: Does this tutorial help? It consists of three steps: Enabling transparency, overriding

问题 I've been trying to figure out a way to resize a PNG image without losing color data from pixels that are completely transparent. Here is the code that I'm using to achieve this: //sourceImage is also a bitmap read in earlier using (var scaledBitmap = new Bitmap(desiredWidth, desiredHeight, PixelFormat.Format32bppArgb)){ using (var g = Graphics.FromImage(scaledBitmap)){ var attr = new ImageAttributes(); attr.SetWrapMode(WrapMode.TileFlipXY); g.CompositingQuality = CompositingQuality

问题 i have a png file which must be converted to a gif file. There is a transparent part in it, and when i save it the transparent part is black in stead of transparent. here's my code: FileStream imgStream = new FileStream(outputFile, FileMode.Create, FileAccess.Write); Image.FromFile(imageInput).Save(imgStream, ImageFormat.Gif); here, imageinput is the fullpath to my png, and output file is the filefullpath with .gif extension. can you see what is wrong here? michel 回答1: PNG uses alpha

问题 How can I rotate the hue of an image using GDI+'s ImageAttributes (and presumably ColorMatrix )? Note that I want to rotate the hue, not tint the image. EDIT : By rotating the hue, I mean that each color in the image should be shifted to a different color, as opposed to making the entire image a shade of one color. For example, Original:http://www.codeguru.com/img/legacy/gdi/Tinter03.jpg Rotated: http://www.codeguru.com/img/legacy/gdi/Tinter15.jpg or http://www.codeguru.com/img/legacy/gdi

问题 I have a multi-page TIFF that I'm splitting up page by page using Leadtools, and changing the compression on them to be compatible with a third party. When I try to save the image to a memoryStream, I get a Parameter is not valid exception. However, this only happens on their machine, or my test machine running Server 2008. I cannot reproduce this on my development machine (Win 7 using VS2008). Here is the code: RasterImage image = codecs.Load( file, 0, CodecsLoadByteOrder.RgbOrGray,

问题 I have some code like this: public void SaveImage(int Counter) { var task = Task.Factory.StartNew(() => { var image = FinalImage; if (image != null) { image.Save(FinalImageSaveLocation + "test" + Counter + ".bmp"); } }, TaskCreationOptions.PreferFairness); } I have a for loop creating x amount of images using similar code below: for(int i = 0; i < 100; i++) { Pencil.DrawImage(image, x, y); //Pencil is created at a initialisation stage SaveImage(i); //by Pencil = Graphics.FromImage(FinalImage)

问题 I have put this simple code together to draw a line. Now I want to apply a ScaleTransform to it by a factor of 10; but the code below doesn't work. var bitmap = new Bitmap(pictureBox1.Size.Width, pictureBox1.Size.Height); var g = Graphics.FromImage(bitmap); pictureBox1.Image = bitmap; var pn = new Pen(Color.Wheat, -1); g.DrawLine(pn, 0, 0, 10, 10); pn.Dispose(); // I'm trying to scaletransform here! g.ScaleTransform(10, 10); Update: What is the correct way to update the changes? I'm not

问题 I have function which takes a bitmap, copies part of it and saves it as 8bpp tiff. Filename of the result image is unique and file doesn't exist, program has permission to write to the target folder. void CropImage(Bitmap map) { Bitmap croped = new Bitmap(200, 50); using (Graphics g = Graphics.FromImage(croped)) { g.DrawImage(map, new Rectangle(0, 0, 200, 50), ...); } var encoderParams = new EncoderParameters(2); encoderParams.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder