Virtual Developer Workshop: Containerized Development with Docker
For example, I often have to create a form that displays a tabulated list box of information (say contacts). The form needs to know which item should be initially selected, and I want to know which item the user chose in the end.
Sharing of this information can be accomplished through the use of public variables, but that is not the best way of going about it.
Create a standard EXE project and add an extra form to it. Place a command button on the first form and a listbox with a button on the second.
Place this code in the first form:
private Sub Command1_Click() MsgBox Form2.ShowList(4) End Sub
Place this code in the second form:
Dim iSelectedIndex as Integer private Sub Command1_Click() me.Hide End Sub private Sub Form_Load() for i = 0 to 20 List1.AddItem "Item " & i next i List1.ListIndex = iSelectedIndex End Sub ' This is where the magic happens ' Note that we have to display a modal form to prevent ' the continuation of this function until we are ready. public Function ShowList(Initial as Integer) as string iSelectedIndex = Initial ' Store the parameter ' for later use me.Show 1 ' Display the form ShowList = List1.List(List1.ListIndex) ' Return Unload me End Function
Not only does this avoid using public variables for the purpose, but we also get excellent portability since now we can just copy the form to use in a different project. None of the code is affected. We have wrapped a form into a function!