ASP.NET: MVC Bitmap Image Creation and Download

Download any file type from a controller in ASP.NET MVC using FileContentResult.

This example creates a bitmap (jpeg) and sends it to the browser. The key is copying the output to a byte array.

See also: ASP.NET Core: MVC Bitmap Image Creation and Download

// Controller Method
public FileContentResult CreateBitmap()
{
	int height = 200;
	int width = 200;
	System.Random r = new System.Random();
	using (System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(width, height, System.Drawing.Imaging.PixelFormat.Format24bppRgb))
	{
		using(System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bmp))
		{
			g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
			g.Clear(System.Drawing.Color.LightGray);
			g.DrawRectangle(System.Drawing.Pens.White, 1, 1, width - 3, height - 3);
			g.DrawRectangle(System.Drawing.Pens.Gray, 2, 2, width - 3, height - 3);
			g.DrawRectangle(System.Drawing.Pens.Black, 0, 0, width, height);
			g.DrawString("Refresh Me!", new System.Drawing.Font("Arial", 10, System.Drawing.FontStyle.Bold),
				System.Drawing.SystemBrushes.WindowText, new System.Drawing.PointF(r.Next(50), r.Next(100)),
				new System.Drawing.StringFormat(System.Drawing.StringFormatFlags.DirectionVertical));
			g.FillRectangle(new System.Drawing.SolidBrush(System.Drawing.Color.FromArgb(r.Next(155), r.Next(255),
				r.Next(255), r.Next(255))), r.Next(width), r.Next(height), 100, 50);
			int x = r.Next(width);
			g.FillRectangle(new System.Drawing.Drawing2D.LinearGradientBrush(new System.Drawing.Point(x, 0),
				new System.Drawing.Point(x + 75, 100), System.Drawing.Color.FromArgb(128, 0, 0, r.Next(255)),
				System.Drawing.Color.FromArgb(255, r.Next(192, 255), r.Next(192, 255), r.Next(255))), x, r.Next(height), 75, 50);
			string filename = Server.MapPath("/") + System.Guid.NewGuid().ToString("N");
			bmp.Save(filename, System.Drawing.Imaging.ImageFormat.Jpeg);
			byte[] bytes;
			using (System.IO.FileStream stream = new System.IO.FileStream(filename, System.IO.FileMode.Open))
			{
				bytes = new byte[stream.Length];
				stream.Read(bytes, 0, bytes.Length);
			}
			System.IO.File.Delete(filename);
			return new FileContentResult(bytes, "image/jpeg");
		}
	}
}

Comment