I haven't written anything with GDI for a while now (and never with GDI+), and I'm just working on a fun project, but for the life of me, I can't figure out how to double buffer GDI+ void DrawStuff(HWND hWnd) { HDC hdc; HDC hdcBuffer; PAINTSTRUCT ps; hdc = BeginPaint(hWnd, &ps); hdcBuffer = CreateC...
Is there a simple way to convert a System.Drawing.Pen into its unmanaged counterpart? Like, if you had a Pen like this: Pen p = new Pen(Color.Blue, 1f); IntPtr ptr = p.ToPtr(); I know this code doesn't work, but is there a way to do it similarly? ...
Hi, I have the following code to take a screenshot of a window, and get the colour of a specific pixel in it: void ProcessScreenshot(HWND hwnd){ HDC WinDC; HDC CopyDC; HBITMAP hBitmap; RECT rt; GetClientRect (hwnd, &rt); WinDC = GetDC (hwnd); CopyDC = CreateCompatibleDC (WinDC); //Create a bitmap compatible with the DC hBitmap = Cre...
So here's my issue. I have an image that I need to shrink. The original image is a grayscale PNG, which isn't a huge issues except that when I shrink it down, the thermal label printers pickup the artifacts and print them on the label. So, what I did was change the image to black & white (Format1bppIndexed) before resizing, like this:...
What is the best way to set the RGB components of every pixel in a System.Drawing.Bitmap to a single, solid color? If possible, I'd like to avoid manually looping through each pixel to do this. Note: I want to keep the same alpha component from the original bitmap. I only want to change the RGB values. I looked into using a ColorMatrix...
My VB.NET program currently takes a 4BPP TIFF as an Bitmap, converts it to a Graphic, adds some text strings and then saves it out again as a TIFF file. The output Bitmap.Save() TIFF file by default seems to be 24BPP (regardless of the input) and is a lot larger than the original TIFF. Is it possible to keep the same 4BPP palette encodi...
I am creating screenshots under Windows and using the LockBits function from GDI+ to extract the pixel data, which will then be written to a file. To maximise performance I am also: Using the same PixelFormat as the source bitmap, to avoid format conversion Using the ImageLockModeUserInputBuf flag to extract the pixel data into a pre-...
Hello everybody. I'm trying to create a WinForms app that takes a screenshot on a set interval. I think my code is correct, but when I try to run it, I get the error message "System.Runtime.InteropServices.ExternalException was unhandled, A generic error occurred in GDI+." System.Windows.Forms.Timer t = new System.Windows.Forms.Time...
When I attempt to save an image file to a virtual directory I get "A generic error occurred in GDI+." This seems to be a permission issue, because during the debug process, I changed the file path to my local hard drive and was able to save the file. The virtual directory is running under a specific domain account, with full control g...
I've got window on a WinForm that I want to get the bitmap representation of. For this, I use the following code (where codeEditor is the control I want a bitmap representation of): public Bitmap GetBitmap( ) { IntPtr srcDC = NativeMethods.GetDC( codeEditor.Handle ) ; var bitmap = new Bitmap( codeEditor.Width, co...
I've been told that using GDI+ from ASP.NET is dangerous and undefined. Is that because there is no guarantee of a Device Context? Can someone explain? What are some of the alternatives? Here is the MSDN source: http://msdn.microsoft.com/en-us/library/system.drawing.aspx Edit Windows and ASP.NET service! So perhaps a normal ASP.N...
Hi all, I have written the following IronPython code: import clr clr.AddReference("System.Drawing") from System import * from System.Drawing import * from System.Drawing.Imaging import * def NoWorko(bitmap): bmData = bitmap.LockBits(Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadWrite, PixelFormat.Format2...
I am storing bitmap-like data in a two-dimensional int array. To convert this array into a GDI-compatible bitmap (for use with BitBlt), I am using this function: public IntPtr GetGDIBitmap(int[,] data) { int w = data.GetLength(0); int h = data.GetLength(1); IntPtr ret = IntPtr.Zero; using (Bitmap bmp = new Bitmap(w, h)...
I'm looking for a way to speed up the drawing of my game engine, which is currently the significant bottleneck, and is causing slowdowns. I'm on the verge of converting it over to XNA, but I just noticed something. Say I have a small image that I've loaded. Image img = Image.FromFile("mypict.png"); We have a picturebox on the scr...
I have polygons of various shapes and sizes. They have a solid fill and currently a solid border. I would like to give the polygons a gradient on their edge to soften them. So far I've tried using a Pen with a LinearGradientBrush and whilst the effect it produces is very interesting it's most definitely not what I want ;) I've looked ...
hi, i'm trying to edit the pixels of a 8bpp. Since this PixelFormat is indexed i'm aware that it uses a Color Table to map the pixel values. Even though I can edit the bitmap by converting it to 24bpp, 8bpp editing is much faster (13ms vs 3ms). But, changing each value when accessing the 8bpp bitmap results in some random rgb colors even...
I have an application that works with Enhanced Metafiles. I am able to create them, save them to disk as .emf and load them again no problem. I do this by using the gdi32.dll methods and the DLLImport attribute. However, to enable Version Tolerant Serialization I want to save the metafile in an object along with other data. This esse...
After working with the .NET GDI+ Rectangle object, I've noticed that if I create a rectangle that is X:0 * Y:0 * Width:100 * Height:100, the Right and Bottom properties are set to 100, 100. Shouldn't this be 99, 99? 0 - 99 is 100 pixels. 0 - 100 is 101 pixels. FWIW, the documentation does say the right is computed by x + width and th...
The standard windows Charmap utility shows quite a few characters in the "Wingdings 2" font whose character codes are greater than 255 - for example, 0xE4E shows a hand. However, if I try to draw these characters as follows: g.DrawString(new string((char) 0xE4E, 1), new Font("Wingdings 2", 20), brush, x, y); then all I get is a stand...
I wrote something to load PNG files from a custom C++ IStream via GDI+. It worked great until I ran it on Vista machines. Crashes every time. When compiled on VS 2008, I found that inserting code into the IStream::AddRef method, such as a cout, made the problem go away. When compiling with VS 2010, it still crashes regardless of that. ...