[VB.NET]下拉列的问题

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下拉列的问题
怎么设置可以用一个快捷键调出DropDownList的下拉列表框
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Private Sub Form1_KeyDown( _
ByVal sender As System.Object, _
ByVal e As System.Windows.Forms.KeyEventArgs _
) Handles MyBase.KeyDown

If e.KeyCode = Keys.A AndAlso e.Alt Then
Me.ComboBox1.Focus()
Me.ComboBox1.DroppedDown = True
End If

End Sub

Private Sub Form1_Load( _
ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles MyBase.Load

Me.KeyPreview = True

End Sub
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