无论如何缩短它？

Question

嗨，我是编程新手。有没有办法缩短我的计划？

Private Sub ComboBox10_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox10.SelectedIndexChanged

        If ComboBox9.Text = "Power" Then

            If ComboBox8.Text = "Cable" Then
                ComboBox11.Items.Add("Black")
                ComboBox11.Items.Add("Brown")
                ComboBox11.Items.Add("Red")
                ComboBox11.Items.Add("White")
                ComboBox11.Items.Add("Grey")
                ComboBox11.Items.Add("Vio")
            End If
End If

Private Sub ComboBox11_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox11.SelectedIndexChanged

        If ComboBox9.Text = "Power" Then

            If ComboBox8.Text = "Cable" Then
                ComboBox11.Items.Add("Black")
                ComboBox11.Items.Add("Brown")
                ComboBox11.Items.Add("Red")
                ComboBox11.Items.Add("White")
                ComboBox11.Items.Add("Grey")
                ComboBox11.Items.Add("Vio")
            End If
End If

Private Sub ComboBox12_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox12.SelectedIndexChanged

        If ComboBox9.Text = "Power" Then

            If ComboBox8.Text = "Cable" Then
                ComboBox11.Items.Add("Black")
                ComboBox11.Items.Add("Brown")
                ComboBox11.Items.Add("Red")
                ComboBox11.Items.Add("White")
                ComboBox11.Items.Add("Grey")
                ComboBox11.Items.Add("Vio")
            End If
End If

Private Sub ComboBox13_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox13.SelectedIndexChanged

        If ComboBox9.Text = "Power" Then

            If ComboBox8.Text = "Cable" Then
                ComboBox11.Items.Add("Black")
                ComboBox11.Items.Add("Brown")
                ComboBox11.Items.Add("Red")
                ComboBox11.Items.Add("White")
                ComboBox11.Items.Add("Grey")
                ComboBox11.Items.Add("Vio")
            End If
End If

Answer 1

Private Sub ComboBox10_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox10.SelectedIndexChanged, ComboBox11.SelectedIndexChanged, ComboBox12.SelectedIndexChanged, ComboBox13.SelectedIndexChanged
    If ComboBox9.Text = "Power" AndAlso ComboBox8.Text = "Cable" Then
        ComboBox11.Items.Add(New String() {"Black", "Brown", "Red", "White", "Grey", "Vio"})
    End If
End Sub