public partial class MainWindow : Window { public MainWindow() { InitializeComponent(); } Form1 f1; IntPtr intptrChild = IntPtr.Zero; private void btnOPen_Click(object sender, RoutedEventArgs e) { IntPtr intptrParent = myUCParent.PanlParent.Handle; // f1 = new Form1(); f1.Show(); intptrChild = f1.Handle; // Thread tt = new Thread(() => { while (true) { if (intptrChild != IntPtr.Zero) { this.Dispatcher.Invoke(new Action(() => { EmbeddedApp.SetParent(intptrChild, intptrParent); EmbeddedApp.MoveWindow(intptrChild, 0, 0, myUCParent.PanlParent.Width, myUCParent.PanlParent.Height, true); EmbeddedApp.ShowWindow(intptrChild, 5); })); break; } } }); tt.IsBackground = true; tt.Start(); } private void windowsFormsHost1_SizeChanged(object sender, SizeChangedEventArgs e) { if (f1 == null) return; EmbeddedApp.MoveWindow(f1.Handle, 0, 0, myUCParent.PanlParent.Width, myUCParent.PanlParent.Height, true); } }