تحرير

مشاركة عبر

How to: Bind to an ADO.NET Data Source

  • مقالة

This example shows how to bind a Windows Presentation Foundation (WPF) ListBox control to an ADO.NET DataSet.

Example

In this example, an OleDbConnection object is used to connect to the data source which is an Access MDB file that is specified in the connection string. After the connection is established, an OleDbDataAdapter object is created. The OleDbDataAdapter object executes a select Structured Query Language (SQL) statement to retrieve the recordset from the database. The results from the SQL command are stored in a DataTable of the DataSet by calling the Fill method of the OleDbDataAdapter. The DataTable in this example is named BookTable. The example then sets the DataContext property of the ListBox to the DataSet object.

DataSet myDataSet;

private void OnInit(object sender, EventArgs e)
{
  string mdbFile = Path.Combine(AppDataPath, "BookData.mdb");
  string connString = string.Format(
      "Provider=Microsoft.Jet.OLEDB.4.0; Data Source={0}", mdbFile);
  OleDbConnection conn = new OleDbConnection(connString);
  OleDbDataAdapter adapter = new OleDbDataAdapter("SELECT * FROM BookTable;", conn);

  myDataSet = new DataSet();
  adapter.Fill(myDataSet, "BookTable");

  // myListBox is a ListBox control.
  // Set the DataContext of the ListBox to myDataSet
  myListBox.DataContext = myDataSet;
}

Private myDataSet As DataSet

Private Sub OnInit(ByVal sender As Object, ByVal e As EventArgs)
  Dim mdbFile As String = Path.Combine(AppDataPath, "BookData.mdb")
  Dim connString As String = String.Format("Provider=Microsoft.Jet.OLEDB.4.0; Data Source={0}", mdbFile)
  Dim conn As New OleDbConnection(connString)
  Dim adapter As New OleDbDataAdapter("SELECT * FROM BookTable;", conn)

  myDataSet = New DataSet()
  adapter.Fill(myDataSet, "BookTable")

  ' myListBox is a ListBox control.
  ' Set the DataContext of the ListBox to myDataSet
  myListBox.DataContext = myDataSet
End Sub

We can then bind the ItemsSource property of the ListBox to BookTable of the DataSet:

<ListBox Name="myListBox" Height="200"
  ItemsSource="{Binding Path=BookTable}"
  ItemTemplate  ="{StaticResource BookItemTemplate}"/>

BookItemTemplate is the DataTemplate that defines how the data appears:

<StackPanel.Resources>
  <c:IntColorConverter x:Key="MyConverter"/>

  <DataTemplate x:Key="BookItemTemplate">
    <Grid>
      <Grid.ColumnDefinitions>
        <ColumnDefinition Width="250" />
        <ColumnDefinition Width="100" />
        <ColumnDefinition Width="*"/>
      </Grid.ColumnDefinitions>
      <TextBlock Text="{Binding Path=Title}" Grid.Column="0"
        FontWeight="Bold" />
      <TextBlock Text="{Binding Path=ISBN}" Grid.Column="1" />
      <TextBlock Grid.Column="2" Text="{Binding Path=NumPages}"
                 Background="{Binding Path=NumPages,
          Converter={StaticResource MyConverter}}"/>
    </Grid>
  </DataTemplate>
</StackPanel.Resources>

The IntColorConverter converts an int to a color. With the use of this converter, the Background color of the third TextBlock appears green if the value of NumPages is less than 350 and red otherwise. The implementation of the converter is not shown here.

See also