WPF中的Popup控件挡住了输入法解决方法

WPF中的Popup控件挡住了输入法
 
WPF中的Popup控件挡住了输入法，但我的输入焦点是在Popup里的一个TextBox上啊。大家帮忙看看怎么解决啊

[解决办法]
WPF中自带的Popup作为弹出对话框确实有这个问题，你可以自己写一个popup，让他只在应用程序上面，不要在所有窗体最上面，网上有现成的代码：

C# code

public class PopupNonTopmost : Popup{    public static DependencyProperty TopmostProperty = Window.TopmostProperty.AddOwner(        typeof( PopupNonTopmost ),        new FrameworkPropertyMetadata( false, OnTopmostChanged ) );    public bool Topmost    {        get { return (bool)GetValue( TopmostProperty ); }        set { SetValue( TopmostProperty, value ); }    }    private static void OnTopmostChanged( DependencyObject obj, DependencyPropertyChangedEventArgs e )    {        ( obj as PopupNonTopmost ).UpdateWindow();    }    protected override void OnOpened( EventArgs e )    {        UpdateWindow();    }    private void UpdateWindow()    {        var hwnd = ( (HwndSource)PresentationSource.FromVisual( this.Child ) ).Handle;        RECT rect;        if ( GetWindowRect( hwnd, out rect ) )        {            SetWindowPos( hwnd, Topmost ? -1 : -2, rect.Left, rect.Top, (int)this.Width, (int)this.Height, 0 );        }    }    #region P/Invoke imports & definitions    [StructLayout( LayoutKind.Sequential )]    public struct RECT    {        public int Left;        public int Top;        public int Right;        public int Bottom;    }    [DllImport( "user32.dll" )]    [return: MarshalAs( UnmanagedType.Bool )]    private static extern bool GetWindowRect( IntPtr hWnd, out RECT lpRect );    [DllImport( "user32", EntryPoint = "SetWindowPos" )]    private static extern int SetWindowPos( IntPtr hWnd, int hwndInsertAfter, int x, int y, int cx, int cy, int wFlags );    #endregion}