Can I combine a Type with a variable?

[sinnatra]

Hi,

I am taking a beginning VB.Net class and I have a project where I need to check the text of 16 buttons. I can easily do this with If Then statements but I am curious if I could do this by running a For Next loop. Here is the code I have tried:

Dim btn As Integer
Dim x As String
 
        For btn = 1 To 16
            x = btn
            If Button(x).text = "" Then
                MsgBox("Everything appears correct except you still have blanks in the puzzle.")
            End If
        Next btn

Unfortunately, I get the following error: 'Button' is a type and cannot be used as an expression.

Can anyone please help a noob and guide me in the right direction? Thanks!

[Killer42]

Hi sinnatra.

This is one case where M$ appear to have taken a big step backward (though presumably they had their reasons).

In VB6 (pre-.Net version, about 9-10 years old) you can just define the controls as a control array. So if your control name was called Button1, for instance, you could refer to the elements of the array as Button1(x).

In VB.Net apparently they have removed this capability. But there are ways to simulate it, or work around the limitation. There is a Controls collection, which I think exists in both VB6 and later versions. You reference the members by name. For example Form1.Controls("Button1"). The implication of this is that you can get close to the functionality of a control array by dynamically building the name in the string. For example, to access a bunch of buttons called Button1 through Button10, you might do something like this (keeping in mind I only know VB6 syntax)...

Dim I As Long
Dim CtlName As String
For I = 1 to 10
  CtlName = "Button" & Format(I)
  Debug.Print CtlName ; " : "; Form1.Controls(CtlName).Caption
Next
 

If you search through the discussions which have taken place on this topic at TheScripts, you'll also find that I proposed an alternative method some months back, involving the creation of an array in code to represent the controls on the form. I haven't had a chance yet to flesh it out and write it up in the Articles section (assuming it works out). I'm hoping to do so within the next week or two, but things are pretty busy.

Ahah! Found it. Just in case you're interested, here is a link to the original discussion during which I proposed the alternative method.