There are some problem to fix here: → fadeTimer.Interval = 10;: You’re (possibly) using the wrong Timer: the System.Timers.Timer‘s Elapsed is raised in a ThreadPool Thread. Unless you have set the SynchronizingObject to a Control object, which is then used to marshal the handler calls, referencing a Control in the handler will cause trouble (cross-thread … Read more
I propose you a slightly different method, using the GraphicsPath class to both measure and draw the text on a Bitmap object. The advantage is that the GraphicsPath class reports the actual coordinates where the object(s) that it contains will be drawn and also the size of the text, in relation to a specific Font. … Read more
It is pretty rare to exceed the 10,000 object limit for GDI objects only, the garbage collector will take care of them when you don’t call their Dispose() method yourself. A much more likely failure mode is exceeding the object limit for windows. Which is very easy to do in Winforms, Controls.Clear() or Controls.Remove() will … Read more
TLTR The time it takes to do one Region.IsVisible(Point) call doesn’t depend on the number of points at all. Instead it depends on the number of rectangles it takes to fully and precisely cover the region. Which depends on..: the shapes those points describe and usually the size of the shape. Example 1: A rectangular … Read more
OK, after a lot of effort here’s the answer: int SaveJpeg(HBITMAP hBmp, LPCWSTR lpszFilename, ULONG uQuality) { ULONG *pBitmap = NULL; CLSID imageCLSID; EncoderParameters encoderParams; int iRes = 0; typedef Status (WINAPI *pGdipCreateBitmapFromHBITMAP)(HBITMAP, HPALETTE, ULONG**); pGdipCreateBitmapFromHBITMAP lGdipCreateBitmapFromHBITMAP; typedef Status (WINAPI *pGdipSaveImageToFile)(ULONG *, const WCHAR*, const CLSID*, const EncoderParameters*); pGdipSaveImageToFile lGdipSaveImageToFile; // load GdipCreateBitmapFromHBITMAP lGdipCreateBitmapFromHBITMAP = … Read more
We’ve seen this problem too. One way we’ve seen to “fix” it is to completely suspend drawing of the control until we’re ready to go. To accomplish this, we send the WM_SETREDRAW message to the control: // Note that WM_SetRedraw = 0XB // Suspend drawing. UnsafeSharedNativeMethods.SendMessage(handle, WindowMessages.WM_SETREDRAW, IntPtr.Zero, IntPtr.Zero); … // Resume drawing. UnsafeSharedNativeMethods.SendMessage(handle, WindowMessages.WM_SETREDRAW, … Read more
This is because Gdi+ Image class is not thread safe. Hovewer you can avoid InvalidOperationException by using lock every time when you need to Image access, for example for painting or getting image size: Image DummyImage; // Paint lock (DummyImage) e.Graphics.DrawImage(DummyImage, 10, 10); // Access Image properties Size ImageSize; lock (DummyImage) ImageSize = DummyImage.Size; BTW, … Read more
As a simple approach, you can just factor the RGB values: Color c1 = Color.Red; Color c2 = Color.FromArgb(c1.A, (int)(c1.R * 0.8), (int)(c1.G * 0.8), (int)(c1.B * 0.8)); (which should darken it; or, for example, * 1.25 to brighten it)
To fix the text “blockiness”, can’t you just do… g.TextRenderingHint = System.Drawing.Text.TextRenderingHint.ClearTypeGridFit; after this line… Graphics g = Graphics.FromImage( (Image) image );
You could try to save the image using this approach SaveFileDialog dialog=new SaveFileDialog(); if (dialog.ShowDialog()==DialogResult.OK) { int width = Convert.ToInt32(drawImage.Width); int height = Convert.ToInt32(drawImage.Height); using(Bitmap bmp = new Bitmap(width, height)) { drawImage.DrawToBitmap(bmp, new Rectangle(0, 0, width, height)); bmp.Save(dialog.FileName, ImageFormat.Jpeg); } }