Problem with DataGridViewComboBoxCell and Structured Data

I'm using a DataGridViewComboBoxCell in my program, and I'm trying to fill it with choices that are structs. The problem I'm facing is that whenever I select an item in the list, no matter what I choose, the name displayed in the cell defaults to the first item in the list. I've debugged my program, and it's actually using the correct information for what I select, but the cell just displays the wrong name. It will only ever show the first name in the list no matter what I pick.

Here's my structure:

<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Ansi, Pack:=1)> _
    Structure TFm
        <VBFixedString(31), MarshalAs(UnmanagedType.ByValTStr, SizeConst:=31)> Public Name As String
        <VBFixedString(61), MarshalAs(UnmanagedType.ByValTStr, SizeConst:=61)> Public Desc As String
        <VBFixedString(9), MarshalAs(UnmanagedType.ByValTStr, SizeConst:=9)> Public source As String
        Dim Depth As Double '{ Z }
        Dim Symbol As Integer
        <VBFixedString(9), MarshalAs(UnmanagedType.ByValTStr, SizeConst:=9)> Public Quality As String
        <VBFixedString(4097), MarshalAs(UnmanagedType.ByValTStr, SizeConst:=4097)> Public Remarks As String

        'Override ToString Method
        Public Overrides Function ToString() As String
            Return Name
        End Function
    End Structure

Open in new window


I want to see a list of the Name members of my struct data, so as you can see, I've overridden the ToString method for the struct to show the name. I've added items to the list like so:

If Fm.Depth <> 1.0E+30 Then
     cbTopsCell.Items.Add(Fm)
     cbBottomsCell.Items.Add(Fm)
End If

Open in new window


1.0E+30 is just the null value in my data set, so if the Depth value of the structure Fm is not null, then add the structure to the items list. cbTopsCell and cbBottomsCell are both DataGridViewComboBoxCell's.

The reasoning behind adding the structure is that it has other members that I'd like to use for comparisons/data checks later in my program. I'd like to be able to access those other members when a certain item(structure) is selected from the list.

The combobox list gets populated with the Name member of each structure added to the list. So for example, if I have 5 names in the list, and I select Name#3, once I move to a different column, for some reason the value displayed in my combobox is Name#1.
diablo089Asked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

alexey_gusevCommented:
have you set DisplayMember and ValueMember for the combobox?
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
diablo089Author Commented:
I tried this to see if I could get any results:

If e.RowIndex >= 0 AndAlso e.ColumnIndex = 3 Then
      Dim cbTopsCell As DataGridViewComboBoxCell = DataGridView1.Rows(e.RowIndex).Cells("Top")
      i = 2
      cbTopsCell.DisplayMember = cbTopsCell.Items.Item(i).Name
      cbTopsCell.ValueMember = cbTopsCell.DisplayMember
End If

Where column index of 3 is my "Top" column. This just makes the cell go blank after I select an item from the list.
0
alexey_gusevCommented:
no no, I meant that you have to define 2 public properties in your struct which you then set as Display and Value Member for the combobox
0
diablo089Author Commented:
Can you give an example?
0
diablo089Author Commented:
Fixed it.

This article describes the method you suggested of setting DisplayMember and ValueMember for the DataGridViewComboBoxColumn:

http://msdn.microsoft.com/en-us/library/ms404353.aspx

Thanks!
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Visual Basic.NET

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.