ListBox.SetSelected-Methode
Wählt ein angegebenes Element in einer ListBox aus oder hebt dessen Auswahl auf.
Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in system.windows.forms.dll)
Syntax
'Declaration
Public Sub SetSelected ( _
index As Integer, _
value As Boolean _
)
'Usage
Dim instance As ListBox
Dim index As Integer
Dim value As Boolean
instance.SetSelected(index, value)
public void SetSelected (
int index,
bool value
)
public:
void SetSelected (
int index,
bool value
)
public void SetSelected (
int index,
boolean value
)
public function SetSelected (
index : int,
value : boolean
)
Parameter
- index
Der nullbasierte Index des Elements in einer ListBox, das ausgewählt oder dessen Auswahl aufgehoben werden soll.
- value
true, um das angegebene Element auszuwählen, andernfalls false.
Ausnahmen
Ausnahmetyp | Bedingung |
---|---|
Der angegebene Index lag außerhalb des gültigen Wertebereichs. |
|
Die SelectionMode-Eigenschaft wurde auf None festgelegt. |
Hinweise
Mit dieser Eigenschaft können Sie die Auswahl der Elemente in einer ListBox mit Mehrfachauswahl festlegen. Wenn Sie ein Element in einer ListBox mit einfacher Auswahl auswählen möchten, verwenden Sie die SelectedIndex-Eigenschaft.
Beispiel
Im folgenden Codebeispiel wird veranschaulicht, wie ein ListBox-Steuerelement erstellt wird, das mehrere Elemente in Spalten anzeigt und in dessen Liste mehrere Elemente ausgewählt werden können. Im Code für das Beispiel werden der ListBox 50 Elemente mithilfe der Add-Methode der ListBox.ObjectCollection-Klasse hinzugefügt. Anschließend werden drei Elemente aus der Liste mithilfe der SetSelected-Methode ausgewählt. Im Code werden dann über die SelectedItems-Eigenschaft Werte aus der ListBox.SelectedObjectCollection-Auflistung sowie über die SelectedIndices-Eigenschaft Werte aus ListBox.SelectedIndexCollection angezeigt. In diesem Beispiel muss sich der Code in einem Form befinden und aus diesem aufgerufen werden.
Private Sub button1_Click(sender As Object, e As System.EventArgs)
' Create an instance of the ListBox.
Dim listBox1 As New ListBox()
' Set the size and location of the ListBox.
listBox1.Size = New System.Drawing.Size(200, 100)
listBox1.Location = New System.Drawing.Point(10, 10)
' Add the ListBox to the form.
Me.Controls.Add(listBox1)
' Set the ListBox to display items in multiple columns.
listBox1.MultiColumn = True
' Set the selection mode to multiple and extended.
listBox1.SelectionMode = SelectionMode.MultiExtended
' Shutdown the painting of the ListBox as items are added.
listBox1.BeginUpdate()
' Loop through and add 50 items to the ListBox.
Dim x As Integer
For x = 1 To 50
listBox1.Items.Add("Item " & x.ToString())
Next x
' Allow the ListBox to repaint and display the new items.
listBox1.EndUpdate()
' Select three items from the ListBox.
listBox1.SetSelected(1, True)
listBox1.SetSelected(3, True)
listBox1.SetSelected(5, True)
' Display the second selected item in the ListBox to the console.
System.Diagnostics.Debug.WriteLine(listBox1.SelectedItems(1).ToString())
' Display the index of the first selected item in the ListBox.
System.Diagnostics.Debug.WriteLine(listBox1.SelectedIndices(0).ToString())
End Sub
private void button1_Click(object sender, System.EventArgs e)
{
// Create an instance of the ListBox.
ListBox listBox1 = new ListBox();
// Set the size and location of the ListBox.
listBox1.Size = new System.Drawing.Size(200, 100);
listBox1.Location = new System.Drawing.Point(10,10);
// Add the ListBox to the form.
this.Controls.Add(listBox1);
// Set the ListBox to display items in multiple columns.
listBox1.MultiColumn = true;
// Set the selection mode to multiple and extended.
listBox1.SelectionMode = SelectionMode.MultiExtended;
// Shutdown the painting of the ListBox as items are added.
listBox1.BeginUpdate();
// Loop through and add 50 items to the ListBox.
for (int x = 1; x <= 50; x++)
{
listBox1.Items.Add("Item " + x.ToString());
}
// Allow the ListBox to repaint and display the new items.
listBox1.EndUpdate();
// Select three items from the ListBox.
listBox1.SetSelected(1, true);
listBox1.SetSelected(3, true);
listBox1.SetSelected(5, true);
// Display the second selected item in the ListBox to the console.
System.Diagnostics.Debug.WriteLine(listBox1.SelectedItems[1].ToString());
// Display the index of the first selected item in the ListBox.
System.Diagnostics.Debug.WriteLine(listBox1.SelectedIndices[0].ToString());
}
void button1_Click( Object^ /*sender*/, System::EventArgs^ /*e*/ )
{
// Create an instance of the ListBox.
ListBox^ listBox1 = gcnew ListBox;
// Set the size and location of the ListBox.
listBox1->Size = System::Drawing::Size( 200, 100 );
listBox1->Location = System::Drawing::Point( 10, 10 );
// Add the ListBox to the form.
this->Controls->Add( listBox1 );
// Set the ListBox to display items in multiple columns.
listBox1->MultiColumn = true;
// Set the selection mode to multiple and extended.
listBox1->SelectionMode = SelectionMode::MultiExtended;
// Shutdown the painting of the ListBox as items are added.
listBox1->BeginUpdate();
// Loop through and add 50 items to the ListBox.
for ( int x = 1; x <= 50; x++ )
{
listBox1->Items->Add( String::Format( "Item {0}", x ) );
}
listBox1->EndUpdate();
// Select three items from the ListBox.
listBox1->SetSelected( 1, true );
listBox1->SetSelected( 3, true );
listBox1->SetSelected( 5, true );
// Display the second selected item in the ListBox to the console.
System::Diagnostics::Debug::WriteLine( listBox1->SelectedItems[ 1 ] );
// Display the index of the first selected item in the ListBox.
System::Diagnostics::Debug::WriteLine( listBox1->SelectedIndices[ 0 ] );
}
private void button1_Click(Object sender, System.EventArgs e)
{
// Create an instance of the ListBox.
ListBox listBox1 = new ListBox();
// Set the size and location of the ListBox.
listBox1.set_Size(new System.Drawing.Size(200,100));
listBox1.set_Location(new System.Drawing.Point(10,10));
// Add the ListBox to the form.
this.get_Controls().Add(listBox1);
// Set the ListBox to display items in multiple columns.
listBox1.set_MultiColumn(true);
// Set the selection mode to multiple and extended.
listBox1.set_SelectionMode(SelectionMode.MultiExtended);
// Shutdown the painting of the ListBox as items are added.
listBox1.BeginUpdate();
// Loop through and add 50 items to the ListBox.
for (int x = 1; x <= 50; x++) {
listBox1.get_Items().Add(("Item" + (new Integer(x)).ToString()));
}
// Allow the ListBox to repaint and display the new items.
listBox1.EndUpdate();
// Select three items from the ListBox.
listBox1.SetSelected(1,true);
listBox1.SetSelected(3,true);
listBox1.SetSelected(5,true);
// Display the second selected item in the ListBox to the console.
System.Diagnostics.Debug.WriteLine
(listBox1.get_SelectedItems().get_Item(1).ToString());
// Display the index of the first selected item in the ListBox.
System.Diagnostics.Debug.WriteLine((new Integer
(listBox1.get_SelectedIndices().get_Item(0))).ToString());
} //button1_Click
private function button1_Click(sender : Object, e : System.EventArgs)
{
// Create an instance of the ListBox.
var listBox1 : ListBox = new ListBox();
// Set the size and location of the ListBox.
listBox1.Size = new System.Drawing.Size(200, 100);
listBox1.Location = new System.Drawing.Point(10,10);
// Add the ListBox to the form.
this.Controls.Add(listBox1);
// Set the ListBox to display items in multiple columns.
listBox1.MultiColumn = true;
// Set the selection mode to multiple and extended.
listBox1.SelectionMode = SelectionMode.MultiExtended;
// Shutdown the painting of the ListBox as items are added.
listBox1.BeginUpdate();
// Loop through and add 50 items to the ListBox.
for (var x : int = 1; x <= 50; x++)
{
listBox1.Items.Add("Item " + x.ToString());
}
// Allow the ListBox to repaint and display the new items.
listBox1.EndUpdate();
// Select three items from the ListBox.
listBox1.SetSelected(1, true);
listBox1.SetSelected(3, true);
listBox1.SetSelected(5, true);
// Display the second selected item in the ListBox to the console.
System.Diagnostics.Debug.WriteLine(listBox1.SelectedItems[1].ToString());
// Display the index of the first selected item in the ListBox.
System.Diagnostics.Debug.WriteLine(listBox1.SelectedIndices[0].ToString());
}
Plattformen
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile für Pocket PC, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.
Versionsinformationen
.NET Framework
Unterstützt in: 2.0, 1.1, 1.0
Siehe auch
Referenz
ListBox-Klasse
ListBox-Member
System.Windows.Forms-Namespace
SelectedIndex