public bool PreFilterMessage(ref System.Windows.Forms.Message message)
        {
            int hwnd = 0;
            StringBuilder winText = new StringBuilder();
            StringBuilder clsName = new StringBuilder();
            StringBuilder pText = new StringBuilder();
 
//获取鼠标所在位置获取窗体或控件的信息，包括Handle，窗体（控件）的标题，窗体（控件）的类名，父容器的标题
            APImouse.GetWindowFromPoint(ref hwnd, ref winText, ref clsName, ref pText);
 
            // 鼠标左键消息
            if (message.Msg >= 513 && message.Msg <= 515)
            {
                if (hwnd != (int)listBox1.Handle && hwnd != (int)tbBrand.Handle)
                    pnlBrandList.Visible = false;
            }
 
            return false;
        }
 
 
public struct POINT
    {
        public int x;
        public int y;
    }
 
    public class APImouse
    {
        [DllImport("user32.dll", EntryPoint = "GetCursorPos")]
        public static extern int GetCursorPos(ref POINT lpPoint);
        [DllImport("user32.dll", EntryPoint = "WindowFromPoint")]//指定坐标处窗体句柄
        public static extern int WindowFromPoint(int xPoint, int yPoint);
        [DllImport("user32.dll", EntryPoint = "GetWindowText")]//指定坐标处窗体标题
        public static extern int GetWindowText(int hwnd, string lpString, int cch);
 
        [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
        static extern int GetClassName(int hWnd, StringBuilder lpClassName, int nMaxCount);
        [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
        static extern int GetParent(int hWnd);
 
 
        public static void GetWindowFromPoint(ref int hwnd, ref StringBuilder winText, ref StringBuilder clsName, ref StringBuilder pText)
        {
 
            int parentHandle = 0;
            int maxLen = 128;
 
            POINT pnt = new POINT();
 
            parentHandle = GetCursorPos(ref pnt);
 
            hwnd = WindowFromPoint(pnt.x, pnt.y);
 
            winText = new StringBuilder(maxLen);
 
            parentHandle = GetWindowText(hwnd, winText.ToString(), maxLen);
 
            clsName = new StringBuilder(maxLen);
 
            parentHandle = GetClassName(hwnd, clsName, maxLen);
 
            pText = new StringBuilder(maxLen);
 
            parentHandle = GetParent(hwnd);
 
            parentHandle = GetWindowText(parentHandle, pText.ToString(), maxLen);
        }
    }