Panel1双击事件无法使用呀解决方法

    Public Declare Function SendMessage Lib "user32.dll" Alias "SendMessageA" (ByVal hwnd As Integer, ByVal wMsg As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As Integer
    Public Declare Function ReleaseCapture Lib "user32.dll" Alias "ReleaseCapture" () As Integer
    Private Const WM_SYSCOMMAND = &H112
    Private Const SC_MOVE = &HF010&
    Private Const WM_NCLBUTTONDOWN = &HA1
    Private Const HTCAPTION = 2

    Private Sub Panel1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Panel1.MouseDown
        If e.Button = MouseButtons.Left Then
            ReleaseCapture()
            SendMessage(Me.Handle.ToInt32, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0)
        End If
    End Sub