CODEWITHSUNDEEP
vb.netcombobox
Doug Sholly
Doug Sholly

Reputation: 121

How to iterate display values in a combobox

I have a combobox whose values (displayvalue) are formatted (from a database query):

John Doe (11111)

where 11111 is the userID. The UserID is the login name for their machine and I want to default the selected value to the login UserID.

Since combobox.findstring(UserID) only matches if the entry begins with that string, I need to iterate through the values to look for the substring of UserID in the entries.

I've searched around here, but solutions seems to land all around this specific example. I can't seem to find a method that returns the display value at a specific index. What am I missing?

EDIT: This is how I am populating my combobox:

Private Sub PopulateDropdown(strSQl As String, objControl As ComboBox, strTextField As String, strDataField As String)

    Dim objdatareader As New DataTable
    objdatareader = DataAccess.GetDataTable(strSQl)
    objControl.DataSource = objdatareader
    objControl.DisplayMember = strTextField
    objControl.ValueMember = strDataField

End Sub

Upvotes: 1

Views: 1783

Answers (1)

Doug Sholly
Doug Sholly

Reputation: 121

This may actually help folks trying to find the ValueMember of a combobox as well.

I am populating my combobox from a datatable, so this solution may only be valid from that. I am not really sure why this works. I just stumbled upon it.

First, I started by doing a for each item in combobox.items. According to intelisense, there is no property of .value, .text, .DisplayMember, or anything related to that. I did notice that the return type on combobox.items is a DataRowView. I am not sure why that is, but I went with it. One of the members of DataRowView is Row. It turns out, each column from the DataTable is added to the Row collection in 'item's' DataRowView. Rows(0) is the first column, Row(1) is the second, etc. I was then able to look in the Row's full text to find my userid, and then select that row by using the FindExactString of the combobox. The below code works (I built the datatable manually in this example):

dim UserID As String="12345"
dim MyTable as New Datatable
MyTable.Columns.Add("Value", Type.GetType("System.String"))
MyTable.Columns.Add("Text", Type.GetType("System.String"))
MyTable.rows.add("1","Bob Smith(11223)"
MyTable.rows.add("2","George Brown(12345)"
cboAssignedID.datasource=MyTable
cboAssignedID.DisplayMember="Text"
cboAssignedID.ValueMember="Value"

For Each item In cboAssignedID.Items
    If InStr(item.Row(1).ToString, UserID) > 0 Then
        cboAssignedID.SelectedIndex = cboAssignedID.FindStringExact(item.Row(1).ToString)
    End If
Next

Upvotes: 1

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