Using TreeView to Display Records from MDB File in VB.NET 2010

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:

• TreeView: tvData
• Four TextBoxes

txtCompany for Company Name, txtAddress for Address, txtCity for City and , txtCountry for Country.

Two Buttons: For load data and exit application.

Code

There is five procedures:

Private Sub LoadCustomerData()
' for open the database file
        MyDataFile = Application.StartupPath & "\DataFile\Northwind.mdb"
        Dim MyCon As String = "provider=microsoft.jet.oledb.4.0;Password="""";data source=" & MyDataFile
        datCon = New OleDbConnection()
        datCon.ConnectionString = MyCon
        Dim cmdSelect As OleDbCommand = New OleDbCommand()
        Dim datAdp As OleDbDataAdapter = New OleDbDataAdapter()
        datSet = New DataSet()
        Try
            MyTable = "Customers"
            ' Select all fields
            Dim strSql As String = "SELECT * FROM " + MyTable + " ORDER BY ContactName"
            cmdSelect.CommandText = strSql
            cmdSelect.CommandType = CommandType.Text
            datCon.Open()  ' open connection
            cmdSelect.Connection = datCon
            datAdp.SelectCommand = cmdSelect
            datAdp.Fill(datSet, MyTable)  ' fill dataset
            datCon.Close()
            ' if no records then exit:
            Dim RecCount As Integer = Me.BindingContext(datSet, MyTable).Count
            If RecCount = 0 Then
                MessageBox.Show("No records in Customer table file!")
                Exit Sub
            End If
        Catch ex As Exception
            MessageBox.Show(ex.ToString())
        End Try
        SetRootNode()
    End Sub

    Private Sub SetRootNode()
        ' set root node of TreeView:
        tvData.Nodes.Add("Phone Index")
        tvData.Nodes(0).Tag = "RootDB"
        tvData.Nodes(0).ImageIndex = 0
        tvData.Nodes(0).SelectedImageIndex = 0
        ' Set Contact Name
        SetContactName()
        'Set Customer Phone
        SetCustPhone()
    End Sub

Private Sub SetContactName()
'set ContactName field as node
        itmNumber = datSet.Tables(MyTable).Rows.Count
        For i As Integer = 0 To itmNumber - 1
tvData.Nodes(0).Nodes.Add(datSet.Tables(MyTable).Rows(i).ItemArray(2).ToString())
            tvData.Nodes(0).Nodes(i).Tag = "Name"
            tvData.Nodes(0).Nodes(i).ImageIndex = 2
            tvData.Nodes(0).Nodes(i).SelectedImageIndex = 2
        Next
    End Sub

Private Sub SetCustPhone()
'set Phone field as node
        For i As Integer = 0 To itmNumber - 1
tvData.Nodes(0).Nodes(i).Nodes.Add(datSet.Tables(MyTable).Rows(i).ItemArray(9).ToString())
            tvData.Nodes(0).Nodes(i).Nodes(0).Tag = "Phone"
            tvData.Nodes(0).Nodes(i).Nodes(0).ImageIndex = 4
            tvData.Nodes(0).Nodes(i).Nodes(0).SelectedImageIndex = 4
        Next
    End Sub

    Private Sub DisplayRecord(ByVal EmployeeName As String)
        ' Show some data about customer:
        Try
            ' using DataView to find record:
            Dim dv As DataView = New DataView(datSet.Tables(MyTable))
            dv.Sort = "ContactName"
            Dim i As Integer = dv.Find(EmployeeName)
            Me.BindingContext(datSet, MyTable).Position = i
            txtCompany.Text = datSet.Tables(MyTable).Rows(i).ItemArray(1).ToString()
            txtAddress.Text = datSet.Tables(MyTable).Rows(i).ItemArray(4).ToString()
            txtCity.Text = datSet.Tables(MyTable).Rows(i).ItemArray(5).ToString()
            txtCountry.Text = datSet.Tables(MyTable).Rows(i).ItemArray(8).ToString()
        Catch ex As Exception
            MessageBox.Show(ex.ToString())
        End Try
    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.