Como: Acoplar uma Fonte de Dados ADO.NET

Este exemplo mostra como ligar um Windows Presentation Foundation (WPF) ListBox o controle para um ADO.NET DataSet.

Exemplo

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 OleDbDataAdpater object is created. The OleDbDataAdpater 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. O exemplo define o DataContext propriedade da ListBox para o DataSet objeto.

    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

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;
}

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.

Consulte também

Referência

BindingListCollectionView

Conceitos

Revisão de Associação de Dados

Outros recursos

Data Binding How-to Topics