mike mcintyre's

Source Code: Create Simple Database From DataSet And XML File Visual Basic 2005

This article provides the steps necessary to create a simple database from a DataSet and an XML file. It will explain how to use a DataSet and an XML file to implement the database and how to perform CRUD (Create, Retrieve, Update, and Delete) operations on the data stored in the XML file.

The source code uses the DataSet created in the tutorial located at Create Data Table And Columns With DataSet Designer Visual Basic 2005  To follow along with this article download that source code.

Open the solution created in the previous article.

Open the solution's 'ExampleOneForm' in the form designer.

From the Visual Studio menu select Data -> Show Data Sources.

The Data Sources panel shows the 'MyDataSet' DataSet and the 'Customer' table created in the previous article.

Drag and drop the 'Customer' table from the DataSources panel to the surface of 'ExampleOneForm' in the form designer.

A DataGridView and a BindingNavigator will be added to the form. Resize the DataGridView and the form to approximately the size shown in the image below.

Click the BindingNavigator.

A drop down list for adding controls to the BindingNavigator will appear. Select a Label control from the drop down list.

A ToolStripLabel control will be added to the BindingNavigator.

Click the ToolStripLabel control to select it and use the Properties panel to set its Text property to 'Load'.

Finally, replace the code behind the 'ExampleOneForm' with the code below.

 

Imports System.IO

Imports System.Data

 

Public Class ExampleOneForm

 

    Private Sub DemoOneForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        ' Make this form a MDI child of MainForm.

        Me.MdiParent = My.Forms.MainForm

 

        ' Do not allow users to add new rows by clicking the

        ' new row at the end of the DataGridView.

        Me.CustomerDataGridView.AllowUserToAddRows = False

 

        ' Set the CustomerDataGridView's Dock property.

        Me.CustomerDataGridView.Dock = DockStyle.Fill

        ' Maximize the size of this form.

        Me.WindowState = FormWindowState.Maximized

 

        ' If the MyDataSet.XML file already exists enable

        ' the Load label else disable it.

        Me.ToolStripLabel1.Enabled = File.Exists("MyDataSet.xml")

 

        ' Disable the Delete button.

        Me.BindingNavigatorDeleteItem.Enabled = False

    End Sub

 

    ' Load ToolStripLabel.

    Private Sub ToolStripLabel1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ToolStripLabel1.Click

        ' Clear the MyDataSet in memory.

        Me.MyDataSet.Clear()

        ' Read the MyDataSet.xml file into the MyDataSet in memory.

        Me.MyDataSet.ReadXml("MyDataSet.xml")

        ' Disable the Load label and Save Button.

        Me.ToolStripLabel1.Enabled = False

        Me.CustomerBindingNavigatorSaveItem.Enabled = False

    End Sub

 

    Private Sub BindingNavigatorAddNewItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BindingNavigatorAddNewItem.Click

        ' Enable the Save button.

        Me.CustomerBindingNavigatorSaveItem.Enabled = True

    End Sub

 

    Private Sub BindingNavigatorDeleteItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BindingNavigatorDeleteItem.Click

        ' If, after a delete, the Customer DataTable does not have any changes

        ' disable the Save button.

        If Me.MyDataSet.Customer.GetChanges() IsNot Nothing Then

            Me.CustomerBindingNavigatorSaveItem.Enabled = True

        Else

            Me.CustomerBindingNavigatorSaveItem.Enabled = False

        End If

    End Sub

 

    Private Sub CustomerBindingNavigatorSaveItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CustomerBindingNavigatorSaveItem.Click

        ' End editing to prepare for a save.

        Me.CustomerBindingSource.EndEdit()

        Me.CustomerDataGridView.EndEdit()

 

        Try

            Me.MyDataSet.WriteXml("MyDataSet.xml", XmlWriteMode.DiffGram)

            Me.CustomerBindingNavigatorSaveItem.Enabled = False

        Catch ex As Exception

            MessageBox.Show("Exception occured: " & ex.Message, "Save Exception", MessageBoxButtons.OK)

        End Try

    End Sub

 

    Private Sub CustomerDataGridView_CellEndEdit(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles CustomerDataGridView.CellEndEdit

        ' Enable the Save button.

        Me.CustomerBindingNavigatorSaveItem.Enabled = True

    End Sub

End Class

Click the link above to download Visual Basic source code in a Visual Studio 2005 solution which demonstrates how to use a DataSet and an XML file to implement a simple database.