BindingSource.RemoveAt(Int32) Methode

Definition

Entfernt das Element am angegebenen Index aus dieser Liste.Removes the item at the specified index in the list.

public:
 virtual void RemoveAt(int index);
public virtual void RemoveAt (int index);
abstract member RemoveAt : int -> unit
override this.RemoveAt : int -> unit
Public Overridable Sub RemoveAt (index As Integer)

Parameter

index
Int32

Der nullbasierte Index des zu entfernenden Elements.The zero-based index of the item to remove.

Implementiert

Ausnahmen

index ist kleiner als 0 (null) oder größer als der Wert der Count-Eigenschaft.index is less than zero or greater than the value of the Count property.

Die durch die List-Eigenschaft dargestellte zugrunde liegende Liste ist schreibgeschützt oder hat eine feste Größe.The underlying list represented by the List property is read-only or has a fixed size.

Beispiele

Im folgenden Codebeispiel werden die Elemente List, RemoveAtund Count veranschaulicht.The following code example demonstrates the List, RemoveAt, and Count members. Fügen Sie zum Ausführen dieses Beispiels den Code in ein Formular ein, das eine BindingSource mit dem Namen BindingSource1, zwei Bezeichnungen namens label1 und label2und eine Schaltfläche mit dem Namen button1enthält.To run this example, paste the code into a form that contains a BindingSource named BindingSource1, two labels named label1 and label2, and a button named button1. Ordnen Sie die button1_Click-Methode dem Click-Ereignis für button1zu.Associate the button1_Click method with the Click event for button1. Visual Basic Benutzer müssen einen Verweis auf "System. Data. dll" hinzufügen.Visual Basic users will need to add a reference to System.Data.dll.

private void button1_Click(object sender, EventArgs e)
{
    // Create the connection string, data adapter and data table.
    SqlConnection connectionString =
         new SqlConnection("Initial Catalog=Northwind;" +
         "Data Source=localhost;Integrated Security=SSPI;");
    SqlDataAdapter customersTableAdapter =
        new SqlDataAdapter("Select * from Customers", connectionString);
    DataTable customerTable = new DataTable();

    // Fill the adapter with the contents of the customer table.
    customersTableAdapter.Fill(customerTable);

    // Set data source for BindingSource1.
    BindingSource1.DataSource = customerTable;

    // Set the label text to the number of items in the collection before
    // an item is removed.
    label1.Text = "Starting count: " + BindingSource1.Count.ToString();

    // Access the List property and remove an item.
    BindingSource1.List.RemoveAt(4);

    // Remove an item directly from the BindingSource. 
    // This is equivalent to the previous line of code.
    BindingSource1.RemoveAt(4);

    // Show the new count.
    label2.Text = "Count after removal: " + BindingSource1.Count.ToString();
}
    Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) _
        Handles button1.Click

        ' Create the connection string, data adapter and data table.
        Dim connectionString As New SqlConnection("Initial Catalog=Northwind;" & _
            "Data Source=localhost;Integrated Security=SSPI;")
        Dim customersTableAdapter As New SqlDataAdapter("Select * from Customers", _
            connectionString)
        Dim customerTable As New DataTable()

        ' Fill the adapter with the contents of the customer table.
        customersTableAdapter.Fill(customerTable)

        ' Set data source for BindingSource1.
        BindingSource1.DataSource = customerTable

        ' Set the label text to the number of items in the collection before
        ' an item is removed.
        label1.Text = "Starting count: " + BindingSource1.Count.ToString()

        ' Access the List property and remove an item.
        BindingSource1.List.RemoveAt(4)

        ' Remove an item directly from the BindingSource. 
        ' This is equivalent to the previous line of code.
        BindingSource1.RemoveAt(4)

        ' Show the new count.
        label2.Text = "Count after removal: " + BindingSource1.Count.ToString()

    End Sub
End Class

Hinweise

Diese beiden Bedingungen getestet werden können, mit der IsFixedSize und IsReadOnly Eigenschaften bzw.These two conditions can be tested with the IsFixedSize and IsReadOnly properties, respectively.

Diese Methode löst das ListChanged-Ereignis aus.This method raises the ListChanged event.

Gilt für:

Siehe auch