Using private function

Question

Hi I am using following code to run a private function. I have two values in my combo box, One and Two and two private functions with the same names, Private Sub One() and Private Sub Two()

I want my application to call the function whatever value user choses in the combo box. If One is chosen in the combo box, Private function one should be called. Thanks Code is below, that does not work

Public Class Form1

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    Dim vrValue = ComboBox1.Items(1)

    Call vrValue()' In this case vrValue is Two, so Two() should be called.
End Sub
Private Sub two()
    MsgBox("Function called")
End Sub

Answer 1

Dim vrValue = ComboBox1.SelectedItem.ToString()

Select vrValue
    Case "One"
        One()
    Else
        Two()
End Select

Answer 2

Make your subs functions (the only difference is the returning of a value) and put them in their own class:

Public Class RunFunctions
    Dim oMessageBox As MessageBox
    Public Function One() As String
        'oMessageBox = MessageBox
        Return "Message One"

    End Function

    Public Function Two() As String
        Return "Message Two"

    End Function
End Class

Add Each function from the class as an item in your combo box:

Public Class Combo_Functions
    Dim oRunFunction As RunFunctions
    Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As Object _
           , ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged
        MessageBox.Show(ComboBox1.Items(ComboBox1.SelectedIndex()))

    End Sub

    Private Sub Combo_Functions_Load(ByVal sender As Object _
                                       , ByVal e As System.EventArgs) Handles Me.Load
        oRunFunction = New RunFunctions

        ComboBox1.Items.Add(oRunFunction.One())
        ComboBox1.Items.Add(oRunFunction.Two())

    End Sub
End Class

When the combo box is changed (or use the code for the button click) the messagebox for the correct function is executed.

Answer 3

It looks like what you're trying to do is to dynamically call a particular method using a string variable that contains its name. For example, the combo box would contain items "One" and "Two", and you would call the sub named "One" if the first item in the combo box is selected, or the sub named "Two" if the second item is selected. To that end, you may find this article interesting:

http://www.codeproject.com/KB/cs/CallMethodNameInString.aspx

The code in the article is in C#, which shouldn't be too difficult to convert to VB. But here's the translated version of the code for simply invoking a method without passing or returning any parameters (note: I have not tested this code). It simply uses reflection to find the appropriate method:

Public Shared Sub InvokeStringMethod(ByVal typeName As String, ByVal methodName As String)
    'Get the type of the class
    Dim calledType As Type = Type.[GetType](typeName)

    'Invoke the method itself
    calledType.InvokeMember(methodName, BindingFlags.InvokeMethod Or BindingFlags.[Public] Or BindingFlags.[Static], Nothing, Nothing, Nothing)
End Sub

You simply pass the name of the class that contains the method(s) you want to call as the typeName and the name of the method itself that you want to call as the methodName:

InvokeStringMethod("MyClass", "Two")