Question

Is there any way in C# that I can take an empty image and for example draw lines onto it? If possible can you show me an example on how to do this? I’ve seen something like this before but I don’t know to much on how to do it and everywhere online I found was doing it from a pre existing image, then drawing over it. I don’t want to have to load anything, just a nice little thing for an interface I’m working on. I know it sounds like I’m asking for code, but all I’m asking for is how to draw an image without loading anything.

Answer 1

You could use GDI+ (and more specifically the Graphics class):

// Load an existing image into a Graphics object
using (var image = Image.FromFile(@"c:\work\input.png"))
using (var gfx = Graphics.FromImage(image))
{
    // Draw a line on this image from (0x0) to (50x50)
    gfx.DrawLine(new Pen(Color.Red), 0, 0, 50, 50);

    // save the resulting Graphics object to a new file
    using (var output = File.OpenWrite(@"c:\work\output.png"))
    {
        image.Save(output, ImageFormat.Png);
    }
}

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UPDATE:

And if you want to create a new image:

// Create a new image 50x50 in size
using (var image = new Bitmap(50, 50))
using (var gfx = Graphics.FromImage(image))
{
    // Draw a line on this image from (0x0) to (50x50)
    gfx.DrawLine(new Pen(Color.Red), 0, 0, 50, 50);

    // save the resulting Graphics object to a new file
    using (var output = File.OpenWrite(@"c:\work\output.png"))
    {
        image.Save(output, ImageFormat.Png);
    }
}