Addressing a series of textboxes in a loop?

[oldmainframehack]

Hi again!
Having defined a series of textboxes on a form which are logically related, I'd like to assign text to each one in a loop.... The textboxes are numbered TextBox1 through TextBox15, and I'd like to assign each one in turn from a string I'll be parsing out character by character.... Something like this:

        Public letters As String = "ABCDEFGHIJKLMN"
        for I = 0 to (letters.length) -1
           Textbox(I+1).text = letters.substring(I,1)
        next

With the hoped-for result being that TextBox1 contains an "A", TextBox2 contains a "B", and so on.....

Can anybody point me at a more-elegant way to accomplish this? Even a not-so-elegant way that will actually work?

Admittedly it COULD be done (I think) with something dumb like

                Public letters As String = "ABCDEFGHIJKLMN"
        for I = 0 to (letters.length) -1
           if I == 0 then TextBox1.text =  letters.substring(I,1)
           if I == 1 then TextBox2.text =  letters.substring(I,1)
           if I == 2 then TextBox3.text =  letters.substring(I,1)
                    ... Etc....
       next

But that's just Sooooo brute-force!

Suggestions, anybody?

Thanks for any help you gurus (& gurettes!) can offer!

JoeP

[Flashbond]

There are two ways to achieve this. One way is addressing the real control names:

Dim str As String = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
        For i As Integer = 1 To 15 'Assuming having 15 TextBoxes
            For Each c As Char In str
                If c = CType(Me.Controls("Textbox" & i), TextBox).Text Then
                    MsgBox("Textbox" & i & " is " & c.ToString)
                End If
            Next
        Next

Another way is addressing each textbox in fom:

 Dim str As String = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
        For Each Control As TextBox In Me.Controls.OfType(Of TextBox)() 'For each TextBox
            For Each c As Char In str
                If c = Control.Text Then
                    MsgBox(Control.Name & " is " & c.ToString)
                End If
            Next
        Next

[oldmainframehack]

Thanks, Flashbond!
Close, but no cigar.... I want to write the values to the textboxes, not check the values in the textboxes.... I'm liking your first method better than the second, because I won't actually want to address ALL the textboxes..... Just 2-15... So, how would I go about ASSIGNING values to these puppies? Maybe something like

      Me.Controls("Textbox" & I).text = "A"

?

[Shaggy Hiker]

Yes, almost exactly something like that, with one caveat: Every control is in the Controls collection of some container. That code assumes that all of the textboxes are all on the main form (Me). If they are in a groupbox, on a panel, on a tab, or in any other container, they will be in the Controls collection for the container, not the controls collection for the main form.

One other point is that Me.Controls("whatever") will always return an object of type Control. That should be fine for Text, but if you want to do more, you may have to cast it to the proper control:

DirectCast(Me.Controls("whatever"),Textbox).Text

Without the cast, you have a Control, and can only access the properties that are common to the Control class. To access properties specific to some class derived from control, you have to cast it to the appropriate type.

[Flashbond]

Yeah, Shaggy Hiker is right. With his correction:

Dim str As String = "ABCDEFGHIJKLMN"
        For i As Integer = 2 To 15
            DirectCast(Me.Controls("Textbox" & i), TextBox).Text = str.Substring(i - 2, 1)
        Next

[oldmainframehack]

Thanks, Shaggy! All the textboxes I'm needing to stuff stuff in are on the main form(Me.) or on form2, which will have the same textbox numbers as form1... the only other thing on the forms is a couple of pictureboxes that I'm using as "dividers", so nothing fancy.... I'll give it a try without casting anything and see how it goes...

Thanks again!!

Joep

[Shaggy Hiker]

The casting shouldn't be necessary if all you want to access is the .Text property, since that is a member of the control class.

[dday9]

Personally the way that I would do it is by adding all the TextBoxes that you're wanting to assign the text to into a List(Of TextBox). Then rather then iterating through a control's Controls property, you'd iterate through the list. This way the collection you're iterating through is indeed a TextBox and not some other control, plus you get the added benefit of not having to cast the control because it's t value is a TextBox.

[ident]

Personally the way that I would do it is by adding all the TextBoxes that you're wanting to assign the text to into a List(Of TextBox). Then rather then iterating through a control's Controls property, you'd iterate through the list. This way the collection you're iterating through is indeed a TextBox and not some other control, plus you get the added benefit of not having to cast the control because it's t value is a TextBox.

Agreed other then the collection will not change so an array is more suited.

[Evil_Giraffe]

An array is a fixed size mass of mutable state. If the collection isn't changing, an array seems unsuitable as well.

[kleinma]

Yes, almost exactly something like that, with one caveat: Every control is in the Controls collection of some container. That code assumes that all of the textboxes are all on the main form (Me). If they are in a groupbox, on a panel, on a tab, or in any other container, they will be in the Controls collection for the container, not the controls collection for the main form.

One other point is that Me.Controls("whatever") will always return an object of type Control. That should be fine for Text, but if you want to do more, you may have to cast it to the proper control:

DirectCast(Me.Controls("whatever"),Textbox).Text

Without the cast, you have a Control, and can only access the properties that are common to the Control class. To access properties specific to some class derived from control, you have to cast it to the appropriate type.

They added a method to make it easier to find nested controls.

The controls collection of a container (so form, panel, etc..) has a find() method now that takes a control name string and a Boolean you can pass true in to search all child containers.