WinForm用户自定义控件，在主窗体加载时出现闪烁；调用用户控件出现闪烁，需要鼠标才能够显示

protected override CreateParams CreateParams
{
    get
    {
        CreateParams cp = base.CreateParams;
        cp.ExStyle |= 0x02000000;  // Turn on WS_EX_COMPOSITED
        return cp;
    }
}

protected override CreateParams CreateParams
{
    get
    {
        var parms = base.CreateParams;
        parms.Style &= ~0x02000000;  // Turn off WS_CLIPCHILDREN
        return parms;
    }
}