phone index

This is a trial to read records from MDB database file using TreeView control. My project is a phone index to display some fields from Customers table in Northwind database file:

CompanyName, ContactName, Address, City, Country and Phone.

My project has one form (frmPhone), this form has following controls:

txtField(0) for Company Name, txtField(1) for Address, txtField(2) for City and , txtField(3) for Country.

Two Buttons: for load data and exit application.

Code

There is three procedures:

  1. Private Sub LoadCustomerData()
  2. ' for open the database file
  3. Dim strCon As String
  4. Dim strSql As String
  5. On Error GoTo LoadDataErr
  6. MyDataFile = App.Path & "\DataFile\" & "Northwind.mdb"
  7. strCon = "PROVIDER=Microsoft.Jet.OLEDB.4.0;Data Source=" & MyDataFile & ";"
  8. strSql = "SELECT * FROM Customers ORDER BY ContactName"
  9. Set cn = New ADODB.Connection
  10. cn.CursorLocation = adUseClient
  11. cn.Open strCon
  12. Set oCmd = New ADODB.Command
  13. Set oCmd.ActiveConnection = cn
  14. oCmd.CommandType = adCmdText
  15. Set rs = New ADODB.Recordset
  16. rs.Open strSql, cn, adOpenStatic, adLockOptimistic
  17. ' if no records then exit
  18. If rs.RecordCount = 0 Then
  19. MsgBox "No records in Customer table file!"
  20. Exit Sub
  21. End If
  22. SetTreeViewNodes
  23. Exit Sub
  24. LoadDataErr:
  25. MsgBox Err.Description
  26. End Sub
  28. Private Sub SetTreeViewNodes()
  29. 'set two fields (ContactName and Phone) as nodes
  30. Dim cName As String
  31. Dim cPhone As String
  32. Dim NameKey As String
  33. Dim PhoneKey As String
  34. Dim i As Integer
  35. ' set root node of TreeView, (image index = 3)
  36. Set dbNode = tvData.Nodes.Add(, , "RootDB", "Phone Index", 3)
  37. dbNode.Tag = "RootDB"
  38. rs.MoveFirst
  39. i = 0
  40. Do Until rs.EOF
  41. i = i + 1
  42. ' Set Contact Name, (image index = 1)
  43. cName = rs.Fields("ContactName").Value
  44. NameKey = "N" & Str(i)
  45. Set fldNameNode = tvData.Nodes.Add("RootDB", tvwChild, NameKey, cName, 1)
  46. fldNameNode.Tag = "Name"
  47. ' Set Customer Phone, (image index = 5)
  48. PhoneKey = "P" & Str(i)
  49. cPhone = rs.Fields("Phone").Value
  50. Set fldPhoneNode = tvData.Nodes.Add(NameKey, tvwChild, PhoneKey, cPhone, 5)
  51. rs.MoveNext
  52. Loop
  53. rs.MoveFirst
  54. End Sub
  56. Private Sub DisplayRecord(ByVal EmployeeName As String)
  57. 'Show some data about customer in TextBoxes:
  58. rs.MoveFirst
  59. 'find record:
  60. rs.Find ("ContactName = " & "'" & EmployeeName & "'")
  61. 'put the fields in TextBoxes:
  62. txtField(0).Text = rs.Fields(1).Value
  63. txtField(1).Text = rs.Fields(4).Value
  64. txtField(2).Text = rs.Fields(5).Value
  65. txtField(3).Text = rs.Fields(8).Value
  66. End Sub
Summary

I hope that this article be useful in case of use TreeView control, so I invite you to go to source file to read the code about TreeView events. If you have any idea about this code, please tell me. Thanks for C# Corner team and thanks for all.