Saving System.Drawing.Graphics to a png or bmp

Question

I have a Graphics object that I've drawn on the screen and I need to save it to a png or bmp file. Graphics doesn't seem to support that directly, but it must be possible somehow.

What are the steps?

Answer 1

Here is the code:

Bitmap bitmap = new Bitmap(Convert.ToInt32(1024), Convert.ToInt32(1024), System.Drawing.Imaging.PixelFormat.Format32bppArgb); Graphics g = Graphics.FromImage(bitmap);  // Add drawing commands here g.Clear(Color.Green);  bitmap.Save(@"C:\Users\johndoe\test.png", ImageFormat.Png); 

If your Graphics is on a form, you can use this:

private void DrawImagePointF(PaintEventArgs e) {    ... Above code goes here ...     e.Graphics.DrawImage(bitmap, 0, 0); } 

In addition, to save on a web page, you could use this:

MemoryStream memoryStream = new MemoryStream(); bitmap.Save(memoryStream, ImageFormat.Png); var pngData = memoryStream.ToArray();  <img src="data:image/png;base64,@(Convert.ToBase64String(pngData))"/> 

Graphics objects are a GDI+ drawing surface. They must have an attached device context to draw on ie either a form or an image.