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

In this blog you will learn how to use 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.