Combining controls to print in WinForms

[SuperDaveOsbourne]

If you try and print a container control with SkiaSharp controls WinForms, you will find all you get is the image of the control as it is in the design state. To create an image with all them "stitched together" as one image rendered this code might help. Maybe something that should be part of the API, done better of course.

Code Example

` // Stitch images together for one image

    private void BtnStitchControls_Click(object sender, EventArgs e)
    {
        var skChart1 = new SKCartesianChart(CandleStickChart)
        {
            Width = 900,
            Height = 500
        };

        var cartesianChart1Image = skChart1.GetImage();

        var skChart2 = new SKCartesianChart(VolumeBarsChart)
        {
            Width = 900,
            Height = 200
        };

        var cartesianChart2Image = skChart2.GetImage();

        var images = new List<SKImage>
        {
            cartesianChart1Image,
            cartesianChart2Image
        };

        var finalImage = CombineControlImages(images);
        var finalImagePng = finalImage?.Encode(SKEncodedImageFormat.Png, 80);
        using var stream2 = File.OpenWrite(Path.Combine(@"C:\downloads", "FinalImage.png"));
        finalImagePng?.SaveTo(stream2);
    }

    private static SKImage? CombineControlImages(List<SKImage> images)
    {
        //Stitch together images
        //https://github.com/mattleibow/SkiaSharpImageMerger/blob/master/SkiaSharpImageMerger/Program.cs

        try
        {
            var width = 900;
            var height = 700;

            SKImage? finalImage = null;

            //get a surface so we can draw an image
            using var tempSurface = SKSurface.Create(new SKImageInfo(width, height));
            //get the drawing canvas of the surface
            var canvas = tempSurface.Canvas;

            //set background color
            canvas.Clear(SKColors.Transparent);

            //go through each image and draw it on the final image
            int offset = 0; // If you are thinking about going sideways
            int offsetTop = 0;

            foreach (var image in images)
            {
                canvas.DrawImage(image, offset, offsetTop);
                offsetTop = offsetTop + image.Height;
            }

            // return the surface as a manageable image
            finalImage = tempSurface.Snapshot();

            //return the image that was just drawn
            return finalImage;
        }
        finally
        {
            //clean up memory
            foreach (SKImage image in images)
            {
                image.Dispose();
            }
        }`