How to Render a Wpf Usercontrol to a Bitmap Without Creating a Window

How to render a WPF UserControl to a bitmap without creating a window

Ended up using an HwndHost with no actual window.

void cwind()
    {
        Application myapp = new Application();
        mrenderer = new WPFRenderer();
        mrenderer.Width = 256;
        mrenderer.Height = 256;

        HwndSourceParameters myparms = new HwndSourceParameters();
        HwndSource msrc = new HwndSource(myparms);
        myparms.HwndSourceHook = new HwndSourceHook(ApplicationMessageFilter);

        msrc.RootVisual = mrenderer;
        myapp.Run();
    }
    static IntPtr ApplicationMessageFilter(
IntPtr hwnd, int message, IntPtr wParam, IntPtr lParam, ref bool handled)
    {
        return IntPtr.Zero;
    }

WPF rendering control to Bitmap without Window

Oké I am not sure why. As said before I am not very familiar with WPF's internal rendering mechanism and what triggers it, but the solution is to wrap the Chart in a Viewbox. The following code does the trick:

        var viewbox = new Viewbox();
        viewbox.Child = chart;
        viewbox.Measure(chart.RenderSize);
        viewbox.Arrange(new Rect(new Point(0, 0), chart.RenderSize));
        chart.Update(true, true); //force chart redraw
        viewbox.UpdateLayout();

        // RenderTargetBitmap rtb = new RenderTargetBitmap((int)chart.DesiredSize.Width, (int)chart.DesiredSize.Height, 96, 96, PixelFormats.Pbgra32);
        var rtb = new RenderTargetBitmap(500, 500, 96, 96, PixelFormats.Default);
        rtb.Render(chart);

        var encoder = new PngBitmapEncoder();
        encoder.Frames.Add(BitmapFrame.Create(rtb));

        using (var stream = File.OpenWrite(@"D:\bitmap.png")) {
            encoder.Save(stream);
        }

render WPF user control in memory, not on screen

In your case the solution would be something like this:

 public static System.Windows.Controls.Image fromControlToImage(System.Windows.FrameworkElement control)
 {
    Size size = new Size(100, 100); // Or what ever size you want...
    control.Measure(size);
    control.Arrange(new Rect(size));
    control.UpdateLayout();
    ...
 }

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Rending WPF in Memory is quite often asked here at SO:

Drawing Control to Memory

As the control has no parent container, you need to call Measure and Arrange in order to do a proper layout.

WPF Get Size of UIElement in Memory

You need to force a render of the item, or wait for the item to be rendered. You can then use the ActualHeight and ActualWidth properties.

An additional for your purpose:

Force Rendering of a WPF Control in Memory

Propably you can use a ViewBox to render in memory

Generating a PNG from WPF Control in a Windows Service

I'm not sure if you are allowed to create new Windows from a Service. but i can solve your timer problem.

If you want to create one of these timers, the typically need be executed in a STAT-Thread.Why is STAThread required?

Thread timer = new Thread(() =>
{
    while (true)
    {
        //do stuff...

        Thread.Sleep(5000); //wait 5 seconds
    }
 });
 timer.SetApartmentState(ApartmentState.STA); //creates a new Thread for UIs
 timer.IsBackground = true; //if you main Thread exits this will also shutdown.
 timer.Start();

If you don't want to use Lambda

private void MyTimerMethode()
{
    while (true)
    {
        // do stuff...

        Thread.Sleep(5000); //wait 5 seconds
    }
}

    Thread timer = new Thread(MyTimerMethode);
    timer.SetApartmentState(ApartmentState.STA); //creates a new Thread for UIs
    timer.IsBackground = true;
    timer.Start();

If you want to kill it you can use

timer.Abort();

But i recommend using a field like bool isAlive = true; and using it as while loop condition. now if you want to end it you can end it without killing it and throwing any exceptions.

This is what i found after a quick google search for rendering a controls as an image. How to render a WPF UserControl to a bitmap without creating a window

Edit:
I've tried using the code from 'How to render a WPF UserControl to a bitmap without creating a window' and it is working even with a Service.

Render image from UserControl that has LiveChart

For me this works fine for only the chart as well as for the whole user control:
(Note: be sure your usercontrol has a visible background color, if the background is transparent it will be rendered transparent which most image viewer show as black)

EDIT: ok, I guess my solution won't work if the chart isn't visible. But if you can't get it to work otherwise, why not show the usercontrol in a new window, save it and close that window again?

    public static BitmapSource RenderChartAsImage(FrameworkElement chart)
    {
        RenderTargetBitmap image = new RenderTargetBitmap((int)chart.ActualWidth, (int)chart.ActualHeight,
                                                            96, 96, PixelFormats.Pbgra32);
        image.Render(chart);
        return image;
    }

    public static void SaveChartImage(FrameworkElement chart)
    {
        System.Windows.Media.Imaging.BitmapSource bitmap = RenderChartAsImage(chart);

        Microsoft.Win32.SaveFileDialog saveDialog = new Microsoft.Win32.SaveFileDialog();
        saveDialog.FileName += "mychart";
        saveDialog.DefaultExt = ".png";
        saveDialog.Filter = "Image (*.png)|*.png";

        if (saveDialog.ShowDialog() == true)
        {
            using (FileStream stream = File.Create(saveDialog.FileName))
            {
                System.Windows.Media.Imaging.PngBitmapEncoder encoder = new System.Windows.Media.Imaging.PngBitmapEncoder();
                encoder.Frames.Add(System.Windows.Media.Imaging.BitmapFrame.Create(bitmap));
                encoder.Save(stream);
            }
        }
    }

How to create an image of a WPF UserControl at runtime

You can render a WPF control to a bitmap using RenderTargetBitmap, then this image can be copied to the clipboard, saved to a file, or used as part of your GUI

Check out Get a bitmap image from a Control view

Beware with this that you can hit problems when parts of the control you are trying to render are not visible (within a scroll viewer perhaps)

WPF Copy image of control to bitmap

Here is what I ended up with...

        tempWidth = myControl.ActualWidth;
        tempHeight = myControl.ActualHeight;

        myControl.Width = double.NaN;
        myControl.Height = double.NaN;

        myControl.UpdateLayout();

        RenderTargetBitmap rtb = new RenderTargetBitmap((int)myControl.ActualWidth, (int)myControl.ActualHeight, 96, 96, PixelFormats.Pbgra32);

        rtb.Render(myControl);

        PngBitmapEncoder pbe = new PngBitmapEncoder();
        pbe.Frames.Add(BitmapFrame.Create(rtb));
        MemoryStream stream = new MemoryStream();
        pbe.Save(stream);
        image = (System.Drawing.Bitmap)System.Drawing.Image.FromStream(stream);

        CEGrid.Width = tempWidth;
        CEGrid.Height = tempHeight;

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