I don’t know all of these API’s but I do remember some of them (bad memories) so here’s what I can remember and find from poking around in MSDN and playing with wbemtest which I’m surprised I even remember. I recognize that this answer is probably not ALL that you were hoping for. For the … Read more
This is the most efficient: It grabs a pixel at the location of the cursor, and doesn’t rely on only having one monitor. using System; using System.Drawing; using System.Drawing.Imaging; using System.Runtime.InteropServices; using System.Windows.Forms; using System.Diagnostics; namespace FormTest { public partial class Form1 : Form { [DllImport(“user32.dll”)] static extern bool GetCursorPos(ref Point lpPoint); [DllImport(“gdi32.dll”, CharSet = … Read more
I was able to do exactly what I wanted by using the code from Part 1 and Part 2 of this series: Displaying a Splash Screen with C++ Part 1: Creating a HBITMAP archive Part 2: Displaying the window archive Those blog posts are talking about displaying a splash screen in Win32 C++, but it … Read more
The immediately usable code public class DirectBitmap : IDisposable { public Bitmap Bitmap { get; private set; } public Int32[] Bits { get; private set; } public bool Disposed { get; private set; } public int Height { get; private set; } public int Width { get; private set; } protected GCHandle BitsHandle { get; … Read more
Here is a snippet addressing the 8 orientation values. First a few notes: The EXIF id 0x0112 is for Orientation. This is a helpful EXIF id reference http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/EXIF.html 0x0112 is the hex equivalent of 274. The data type of a PropertyItem.Id is an int, meaning 274 is what is useful here. Additionally, 5029 likely was … Read more
When either a Bitmap object or an Image object is constructed from a file, the file remains locked for the lifetime of the object. As a result, you cannot change an image and save it back to the same file where it originated. http://support.microsoft.com/?id=814675 A generic error occurred in GDI+, JPEG Image to MemoryStream Image.Save(..) … Read more
This will set a single pixel: e.Graphics.FillRectangle(aBrush, x, y, 1, 1);
As it’s a MemoryStream, you really don’t need to close the stream – nothing bad will happen if you don’t, although obviously it’s good practice to dispose anything that’s disposable anyway. (See this question for more on this.) However, you should be disposing the Bitmap – and that will close the stream for you. Basically … Read more
Like this? public static void Test() { using (var image = Image.FromFile(@”c:\logo.png”)) using (var newImage = ScaleImage(image, 300, 400)) { newImage.Save(@”c:\test.png”, ImageFormat.Png); } } public static Image ScaleImage(Image image, int maxWidth, int maxHeight) { var ratioX = (double)maxWidth / image.Width; var ratioY = (double)maxHeight / image.Height; var ratio = Math.Min(ratioX, ratioY); var newWidth = (int)(image.Width … Read more
OK I seem to have found the cause just by sheer luck and its nothing wrong with that particular method, it’s further back up the call stack. Earlier I resize the image and as part of that method I return the resized object as follows. I have inserted two calls to the above method and … Read more