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Question

I have a small program that upon form load runs against an object model and pre-loads a combobox with companycodes from all of our clients in the system.

I'm wondering if i can make it so that instead of choosing from one of the dropdown companies the user can just start typing in the company code and have the box autofill or match what they type based on the company codes pre-loaded into the dropown.

Here is a sample of the code that i currently have.

Imports System.IO

Public Class MainForm

    Dim g_System As MILLSYSTEMLib.System

    Public Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'On Error Resume Next
        Try
            Dim Approved As Integer

            ' Create a Millennium system obects
            g_System = CreateObject("MillSystem.System")

            Dim User As Object = g_System.Login()

            ' See if login worked
            If User Is Nothing Then
                MsgBox("Login failed!")
                Approved = 0
            Else
                'MsgBox("Login successful")
                'if approved=1 then the user is able to access M3
                Approved = 1
            End If

            'populate combo box
            For Each Company In g_System.Companies
                cb_COID.Items.Add(Company.Field("co").ToString)
            Next

        Catch ex As Exception
            Me.Close()
        End Try


    End Sub

    Public Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Try
            'get value of combo boxes

            Dim COID, Year As String
            If cb_COID.SelectedItem = True Then
                COID = cb_COID.SelectedItem
            Else
                COID = cb_COID.Text
            End If

            If cb_Year.SelectedItem = True Then
                Year = cb_Year.SelectedItem
            Else
                Year = cb_Year.Text
            End If

            If IsNothing(COID) Then
                MessageBox.Show("Select a Company Code")
            ElseIf IsNothing(Year) Then
                MessageBox.Show("Select a Year")
                Exit Sub
            End If

            If rb_Storeroom.Checked = True Then
                ofd_Storeroom.InitialDirectory = "\\site\M3\Storeroom\" + COID + "\" + Year + "\"
                ofd_Storeroom.Filter = "Employer W2 Files | *ER_W2.mdoc"
                ofd_Storeroom.ShowDialog()

            ElseIf rb_Archive.Checked = True Then
                ofd_Storeroom.InitialDirectory = "\\site\M3\Archive\Storeroom\" + Year + "\" + COID + "\" + Year + "\"
                ofd_Storeroom.Filter = "Employer W2 Files | *ER_W2.mdoc"
                ofd_Storeroom.ShowDialog()

            Else
                MessageBox.Show("Select a Directory")
                Exit Sub
            End If

        Catch ex As Exception
            MessageBox.Show(ex.Message)

        End Try


    End Sub

    Private Sub ofd_Storeroom_FileOk(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles ofd_Storeroom.FileOk
        If rb_Storeroom.Checked = True Then
            tb_Storeroom.Text = ofd_Storeroom.FileName
        ElseIf rb_Archive.Checked = True Then
            tb_Archive.Text = ofd_Storeroom.FileName
        End If

        ofd_Storeroom.FileName = ""

    End Sub

    Private Sub btn_ViewFile_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btn_ViewFile.Click
        Dim StoreSource As String = tb_Storeroom.Text
        Dim ArchSource As String = tb_Archive.Text
        Dim Temp As String = "\\site\M3\Test\W2\"
        Dim fName As String = Path.GetFileName(StoreSource)
        Dim fName2 As String = Path.GetFileName(ArchSource)

        If rb_Storeroom.Checked = True Then
            File.Copy(StoreSource, Path.Combine(Temp, fName), True)
        ElseIf rb_Archive.Checked = True Then
            File.Copy(ArchSource, Path.Combine(Temp, fName2), True)
        End If

        Dim p As New Process
        Dim psi As New ProcessStartInfo("C:\program files\7-zip\7z", "x" & " " & Temp & " " & "-o" & "-y" & Temp)
        p.StartInfo = psi
        p.Start()
        p.WaitForExit()

        If rb_Storeroom.Checked = True Then
            Process.Start(Temp + fName + ".pdf")
        ElseIf rb_Archive.Checked = True Then
            Process.Start(Temp + fName2 + ".pdf")
        End If

        fName = ""
        fName2 = ""

    End Sub
    Private Sub btn_nwsrch_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btn_nwsrch.Click
        Dim Temp As String = "\\site\M3\Test\W2"
        Try
            For Each tb In Me.Controls.OfType(Of TextBox)()
                tb.Text = String.Empty
            Next tb

            For Each rb In Me.Controls.OfType(Of RadioButton)()
                rb.Checked = False
            Next rb

            For Each cb In Me.Controls.OfType(Of ComboBox)()
                cb.Text = String.Empty
            Next cb

            For Each filename As String In IO.Directory.GetFiles(Temp)
                IO.File.Delete(filename)
            Next
        Catch ex As Exception
            MessageBox.Show("You must close the PDF first")
            Exit Sub
        End Try
    End Sub
    Sub frmMain_FormClosing(ByVal sender As System.Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
        Dim Temp As String = "\\site\M3\Test\W2"
        Try
            For Each filename As String In IO.Directory.GetFiles(Temp)
                IO.File.Delete(filename)
            Next
        Catch ex As Exception
            MessageBox.Show("You must close the PDF first")
            Exit Sub
        End Try
    End Sub
End Class

Answer 1

Change the AutoCompleteMode to Suggest . This is a property of the ComboBox. Also make sure to change the AutoCompleteSource to ListItems , that will use its own list of items as the AutoComplete source.

http://msdn.microsoft.com/en-us/library/system.windows.forms.autocompletemode.aspx