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ListBox::SetSelected Method

Selects or clears the selection for the specified item in a ListBox.

Namespace:  System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

public:
void SetSelected(
	int index, 
	bool value
)

Parameters

index
Type: System::Int32

The zero-based index of the item in a ListBox to select or clear the selection for.

value
Type: System::Boolean

true to select the specified item; otherwise, false.

ExceptionCondition
ArgumentOutOfRangeException

The specified index was outside the range of valid values.

InvalidOperationException

The SelectionMode property was set to None.

You can use this property to set the selection of items in a multiple-selection ListBox. To select an item in a single-selection ListBox, use the SelectedIndex property.

The following code example demonstrates how to create a ListBox control that displays multiple items in columns and can have more than one item selected in the control's list. The code for the example adds 50 items to the ListBox using the Add method of the ListBox::ObjectCollection class and then selects three items from the list using the SetSelected method. The code then displays values from the ListBox::SelectedObjectCollection collection (through the SelectedItems property) and the ListBox::SelectedIndexCollection (through the SelectedIndices property). This example requires that the code is located in and called from a Form.

   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 );

      #if defined(DEBUG)
      // 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 ] );
      #endif
   }

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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