Hosting WPF UserControl in a transparent Windows.Form

Question

I need to insert my WPF USerControl into a Windows.Form. This is my control:

<UserControl x:Class="WpfControlLibrary1.UserControl1"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             Background="Transparent">

    <InkCanvas x:Name="Ink" Background="Transparent" />

</UserControl>

To host this control I use an ElementHost object as the only one control of my Form. I need to have the possibility to do the following: when I set the opacity of the form to 0, in order to make it invisible, I need to continue to have the opacity of all the Children and Strokes of My InkCanvas to 1 (so I can see them).

I tried using the TransparencyKey property, but it seems it doesn't work with the ElementHost. How can I solve this problem, and how can I set a different opacity between my Form and my UserControl?

score 1 · Accepted Answer · answered Nov 29 '13 at 13:04

1

AFAIK that's not possible as WPF use Subpixel alpha rendering which is not available with winform for example

Hope this help

answered Nov 29 '13 at 13:04

BRAHIM Kamel

13,492
1
36
47

take a look at this article it may be a starting point http://blogs.msdn.com/b/changov/archive/2009/01/19/webbrowser-control-on-transparent-wpf-window.aspx – BRAHIM Kamel Nov 29 '13 at 13:14
but you can immagine a work around like that one ? – BRAHIM Kamel Nov 29 '13 at 13:20

score 1 · Answer 2 · answered Mar 04 '15 at 07:31

If you want to host a WPF control that behaves transparently on Win Forms, follow these steps

Create WPF usercontrol control and set background ="transparent".

Create Win User Control with no controls on it and write following code on its back end:

public WinControl()
{
    InitializeComponent();
}
protected override CreateParams CreateParams
{
    get
    {
        CreateParams cp = base.CreateParams;

        cp.ExStyle |= 0x00000020;
        return cp;
    }
}

Now place WPF usercontrol on Win user control and dock wpfusercontrol to its parent(win user control).
Now drag win user control on the |Win Form and dock win user control to its parent(Form)

And you are done.

score 0 · Answer 3 · answered Dec 08 '13 at 09:32

0

You could possibly use Microsoft.Ink.dll to create your own WinForms-based UserControl that supports handwriting recognition if that is what you are trying to do.

answered Dec 08 '13 at 09:32

Nathan M

873
5
18

Please, can you link any reference? – Nick Dec 20 '13 at 08:33
Sure. I hosted a small example using the Microsoft.Ink DLL, go to http://nmctl.codeplex.com, go to the source tree and download the InkSample directory. The Ink dll SHOULD be found in C:\Windows\assembly ... FYI there are quite a few libraries that Visual Studio doesn't automatically find that are available in that directory and also in C:\Windows\Microsoft.NET) ... – Nathan M Dec 20 '13 at 20:27

Hosting WPF UserControl in a transparent Windows.Form

3 Answers3