Question

How to use a WPF user control in a windows forms application?

Answer 1

From the MSDN:

Use the ElementHost control to place a
WPF UIElement on your Windows Forms
control or form.

Example:

private void Form1_Load(object sender, EventArgs e)
{
    // Create the ElementHost control for hosting the
    // WPF UserControl.
    ElementHost host = new ElementHost();
    host.Dock = DockStyle.Fill;

    // Create the WPF UserControl.
    HostingWpfUserControlInWf.UserControl1 uc =
        new HostingWpfUserControlInWf.UserControl1();

    // Assign the WPF UserControl to the ElementHost control's
    // Child property.
    host.Child = uc;

    // Add the ElementHost control to the form's
    // collection of child controls.
    this.Controls.Add(host);
}

Here is a nice tutorial how to do that.

The control called ElementHost is for
WPF in WinForms what the
WindowsFormsHost was for WinForms in
WPF. In the designer, you can find
this control in the Toolbox underneath
“WPF Interoperability”.