combo box click event problem

[IsaiahMatz]

Hey guys! I'm having trouble with my code. I want it to calculate the weight of the user on other planets. I want it to calculate as soon as they click the planet from the drop-down-list. The kicker is i have to go through and select it from the list twice to get the correct calculation. Ive been looking around to no avail. Please help. thanks!

Public Class frmMain
    Private Sub CalcMerc(PLANET_GRAV)

        Dim strEarthWeight As String
        Dim dblEarthWeight As Double
        Dim dblPlanetWeight As Double

        strEarthWeight = txtEarth.Text
        Double.TryParse(strEarthWeight, dblEarthWeight)
        dblPlanetWeight = dblEarthWeight * PLANET_GRAV
        txtConverted.Text = dblPlanetWeight.ToString

    End Sub
    Private Sub frmMain_Load(sender As Object, e As EventArgs) Handles MyBase.Load

        cboBox.Items.Add("Mercury")
        cboBox.Items.Add("Venus")
        cboBox.Items.Add("Mars")
        cboBox.Items.Add("Jupiter")
        cboBox.Items.Add("Saturn")
        cboBox.Items.Add("Uranus")
        cboBox.Items.Add("Neptune")
        cboBox.Items.Add("Pluto")
        cboBox.SelectedIndex = 3

    End Sub
    Private Sub cboBox_MouseClick(sender As Object, e As MouseEventArgs) Handles cboBox.MouseClick

        Const MERCURY_GRAV As Double = 0.38
        Const VENUS_GRAV As Double = 0.9
        Const MARS_GRAV As Double = 0.38
        Const JUPITER_GRAV As Double = 2.5
        Const SATURN_GRAV As Double = 0.91
        Const URANUS_GRAV As Double = 0.89
        Const NEPTUNE_GRAV As Double = 1.14
        Const PLUTO_GRAV As Double = 0.08

        If cboBox.SelectedIndex = 0 Then
            CalcMerc(MERCURY_GRAV)
        ElseIf cboBox.SelectedIndex = 1 Then
            CalcMerc(VENUS_GRAV)
        ElseIf cboBox.SelectedIndex = 2 Then
            CalcMerc(MARS_GRAV)
        ElseIf cboBox.SelectedIndex = 3 Then
            CalcMerc(JUPITER_GRAV)
        ElseIf cboBox.SelectedIndex = 4 Then
            CalcMerc(SATURN_GRAV)
        ElseIf cboBox.SelectedIndex = 5 Then
            CalcMerc(URANUS_GRAV)
        ElseIf cboBox.SelectedIndex = 6 Then
            CalcMerc(NEPTUNE_GRAV)
        ElseIf cboBox.SelectedIndex = 7 Then
            CalcMerc(PLUTO_GRAV)
        End If

    End Sub
End Class

[mcupito]

To re-cap: you say it works, but you have to select the option twice in the drop down?

Did you try a different handler? Instead of MouseClick, maybe KeyDown or something else?

[IsaiahMatz]

Yes i had to use the drop down and select it twice. I fixed it! KeyDown did the same thing. But SelectedIndexCh anged works perfectly! Im guessing because its really just an index value. Anywho, thanks a bunch!

[mcupito]

Good - Glad you got it. Whenever you encounter something goofy like that, just remember - it's the handler that is actually trying to use it. So play around with them. You'll learn a lot more that way also.