在输入文本框时自动从组合框填充

我有一个小程序，它在表单加载时运行对象模型，并在系统中预先加载来自我们所有客户端的公司代码的组合框。在输入文本框时自动从组合框填充

我想知道如果我可以做到这一点，而不是选择从下拉公司之一，用户可以开始输入公司代码，并有框自动填充或匹配他们键入什么基于公司代码前被装入dropown。

这是我目前有的代码示例。

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

来源

2013-08-26 BSanders