CF TreeView - Selected Item when control loses focus

I know that "HideSelection" property is missing in CF. But i still need to handle situation when an item is selected that it remains selected (greyed) even when the control looses focus.

I have tried using this peace of code, but with no success. I get an exception in GetFocus() method and i dont know what im doing wrong.

Any help is much appreciated !

[DllImport("User32.dll")]
    static extern IntPtr GetFocus();
    [DllImport("User32.dll")]
    static extern Int32 GetWindowLong(IntPtr hwnd, Int32 integer1);
    [DllImport("User32.dll")]
    static extern IntPtr SetWindo开发者_开发知识库wLong(IntPtr hwnd, Int32 integer1, int integer2);

    private bool doneOnce;
    protected override void OnGotFocus(System.EventArgs e)
    {
        base.OnGotFocus(e);
        if (this.itemsTreeView != null)
        {
            this.itemsTreeView.Focus();
            if (doneOnce == false)
            {
                doneOnce = true;
                IntPtr hWnd = GetFocus();
                Int32 lS = GetWindowLong(hWnd, -16);
                lS = lS | 0x20;
                SetWindowLong(hWnd, -16, lS);
            }
        }
    }

I have put this code in my "code behind" view that holds TreeView control.

Windows CE uses coredll.dll instead of user32.dll.

Some functions are equal on both platforms, while some are not implemented for Compact Framework. I usually check http://www.pinvoke.net for the declares.