ListView.SelectedIndexChanged Evento

public:
 event EventHandler ^ SelectedIndexChanged;

public event EventHandler SelectedIndexChanged;

member this.SelectedIndexChanged : EventHandler 

Public Custom Event SelectedIndexChanged As EventHandler 

Tipo de Evento

Exemplos

O exemplo de código seguinte demonstra como usar a propriedade SelectedItems , SelectedIndexChanged o evento, HeaderStyle os membros e a ListView.SelectedListViewItemCollection classe. Para executar este exemplo, cole o seguinte código numa forma que contenha um ListView objeto nomeado ListView1 e um TextBoxTextBox1. Chama o InitializeListView método a partir do construtor ou Load método da forma. Este exemplo exige que o gestor de eventos esteja corretamente associado ao SelectedIndexChanged evento

// This method adds two columns to the ListView, setting the Text 
// and TextAlign, and Width properties of each ColumnHeader.  The 
// HeaderStyle property is set to NonClickable since the ColumnClick 
// event is not handled.  Finally the method adds ListViewItems and 
// SubItems to each column.
void InitializeListView()
{
   this->ListView1 = gcnew System::Windows::Forms::ListView;
   this->ListView1->BackColor = System::Drawing::SystemColors::Control;
   this->ListView1->Dock = System::Windows::Forms::DockStyle::Top;
   this->ListView1->Location = System::Drawing::Point( 0, 0 );
   this->ListView1->Name = "ListView1";
   this->ListView1->Size = System::Drawing::Size( 292, 130 );
   this->ListView1->TabIndex = 0;
   this->ListView1->View = System::Windows::Forms::View::Details;
   this->ListView1->MultiSelect = true;
   this->ListView1->HideSelection = false;
   this->ListView1->HeaderStyle = ColumnHeaderStyle::Nonclickable;
   ColumnHeader^ columnHeader1 = gcnew ColumnHeader;
   columnHeader1->Text = "Breakfast Item";
   columnHeader1->TextAlign = HorizontalAlignment::Left;
   columnHeader1->Width = 146;
   ColumnHeader^ columnHeader2 = gcnew ColumnHeader;
   columnHeader2->Text = "Price Each";
   columnHeader2->TextAlign = HorizontalAlignment::Center;
   columnHeader2->Width = 142;
   this->ListView1->Columns->Add( columnHeader1 );
   this->ListView1->Columns->Add( columnHeader2 );
   array<String^>^foodList = {"Juice","Coffee","Cereal & Milk","Fruit Plate","Toast & Jelly","Bagel & Cream Cheese"};
   array<String^>^foodPrice = {"1.09","1.09","2.19","2.49","1.49","1.49"};
   for ( int count = 0; count < foodList->Length; count++ )
   {
      ListViewItem^ listItem = gcnew ListViewItem( foodList[ count ] );
      listItem->SubItems->Add( foodPrice[ count ] );
      ListView1->Items->Add( listItem );

   }
   this->Controls->Add( ListView1 );
}

  // This method adds two columns to the ListView, setting the Text 
  // and TextAlign, and Width properties of each ColumnHeader.  The 
  // HeaderStyle property is set to NonClickable since the ColumnClick 
  // event is not handled.  Finally the method adds ListViewItems and 
  // SubItems to each column.
  private void InitializeListView()
  {
      this.ListView1 = new System.Windows.Forms.ListView();
      this.ListView1.BackColor = System.Drawing.SystemColors.Control;
      this.ListView1.Dock = System.Windows.Forms.DockStyle.Top;
      this.ListView1.Location = new System.Drawing.Point(0, 0);
      this.ListView1.Name = "ListView1";
      this.ListView1.Size = new System.Drawing.Size(292, 130);
      this.ListView1.TabIndex = 0;
      this.ListView1.View = System.Windows.Forms.View.Details;
      this.ListView1.MultiSelect = true;
      this.ListView1.HideSelection = false;
      this.ListView1.HeaderStyle = ColumnHeaderStyle.Nonclickable;
      
      ColumnHeader columnHeader1 = new ColumnHeader();
      columnHeader1.Text = "Breakfast Item";
      columnHeader1.TextAlign = HorizontalAlignment.Left;
      columnHeader1.Width = 146;

      ColumnHeader columnHeader2 = new ColumnHeader();
      columnHeader2.Text = "Price Each";
      columnHeader2.TextAlign = HorizontalAlignment.Center;
      columnHeader2.Width = 142;

      this.ListView1.Columns.Add(columnHeader1);
      this.ListView1.Columns.Add(columnHeader2);

      string[] foodList = new string[]{"Juice", "Coffee", 
          "Cereal & Milk", "Fruit Plate", "Toast & Jelly", 
          "Bagel & Cream Cheese"};
      string[] foodPrice = new string[]{"1.09", "1.09", "2.19", 
          "2.49", "1.49", "1.49"};
      
      for(int count=0; count < foodList.Length; count++)
      {
          ListViewItem listItem = new ListViewItem(foodList[count]);
          listItem.SubItems.Add(foodPrice[count]);
          ListView1.Items.Add(listItem);
      }
      this.Controls.Add(ListView1);
  }

' This method adds two columns to the ListView, setting the Text 
' and TextAlign, and Width properties of each ColumnHeader.  The 
' HeaderStyle property is set to NonClickable since the ColumnClick 
' event is not handled.  Finally the method adds ListViewItems and 
' SubItems to each column.
Private Sub InitializeListView()
    Me.ListView1 = New System.Windows.Forms.ListView
    Me.ListView1.BackColor = System.Drawing.SystemColors.Control
    Me.ListView1.Dock = System.Windows.Forms.DockStyle.Top
    Me.ListView1.Location = New System.Drawing.Point(0, 0)
    Me.ListView1.Name = "ListView1"
    Me.ListView1.Size = New System.Drawing.Size(292, 130)
    Me.ListView1.TabIndex = 0
    Me.ListView1.View = System.Windows.Forms.View.Details
    Me.ListView1.MultiSelect = True
    Me.ListView1.HideSelection = False
    ListView1.HeaderStyle = ColumnHeaderStyle.Nonclickable
    Dim columnHeader1 As New ColumnHeader
    With columnHeader1
        .Text = "Breakfast Item"
        .TextAlign = HorizontalAlignment.Left
        .Width = 146
    End With
    Dim columnHeader2 As New ColumnHeader
    With columnHeader2
        .Text = "Price Each"
        .TextAlign = HorizontalAlignment.Center
        .Width = 142
    End With

    Me.ListView1.Columns.Add(columnHeader1)
    Me.ListView1.Columns.Add(columnHeader2)
    Dim foodList() As String = New String() {"Juice", "Coffee", _
        "Cereal & Milk", "Fruit Plate", "Toast & Jelly", _
        "Bagel & Cream Cheese"}
    Dim foodPrice() As String = New String() {"1.09", "1.09", _
        "2.19", "2.49", "1.49", "1.49"}
    Dim count As Integer
    For count = 0 To foodList.Length - 1
        Dim listItem As New ListViewItem(foodList(count))
        listItem.SubItems.Add(foodPrice(count))
        ListView1.Items.Add(listItem)
    Next
    Me.Controls.Add(Me.ListView1)
End Sub

// Uses the SelectedItems property to retrieve and tally the price 
// of the selected menu items.
void ListView1_SelectedIndexChanged_UsingItems( Object^ /*sender*/, System::EventArgs^ /*e*/ )
{
   ListView::SelectedListViewItemCollection^ breakfast = this->ListView1->SelectedItems;
   double price = 0.0;
   System::Collections::IEnumerator^ myEnum = breakfast->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      ListViewItem^ item = safe_cast<ListViewItem^>(myEnum->Current);
      price += Double::Parse( item->SubItems[ 1 ]->Text );
   }

   // Output the price to TextBox1.
   TextBox1->Text = price.ToString();
}

// Uses the SelectedItems property to retrieve and tally the price 
// of the selected menu items.
private void ListView1_SelectedIndexChanged_UsingItems(
    object sender, System.EventArgs e)
{

    ListView.SelectedListViewItemCollection breakfast = 
        this.ListView1.SelectedItems;
    
    double price = 0.0;
    foreach ( ListViewItem item in breakfast )
    {
        price += Double.Parse(item.SubItems[1].Text);
    }

    // Output the price to TextBox1.
    TextBox1.Text = price.ToString();
}

' Uses the SelectedItems property to retrieve and tally the price 
' of the selected menu items.
Private Sub ListView1_SelectedIndexChanged_UsingItems _
    (ByVal sender As Object, ByVal e As System.EventArgs) _
    Handles ListView1.SelectedIndexChanged

    Dim breakfast As ListView.SelectedListViewItemCollection = _
        Me.ListView1.SelectedItems
    Dim item As ListViewItem
    Dim price As Double = 0.0
    For Each item In breakfast
        price += Double.Parse(item.SubItems(1).Text)
    Next

    ' Output the price to TextBox1.
    TextBox1.Text = CType(price, String)
End Sub

Observações

A SelectedIndices coleção muda sempre que a Selected propriedade de uma ListViewItem muda. A alteração de propriedade pode ocorrer de forma programática ou quando o utilizador seleciona um item ou elimina a seleção de um item. Quando o utilizador seleciona um item sem pressionar CTRL para realizar uma seleção múltipla, o controlo primeiro elimina a seleção anterior. Neste caso, este evento ocorre uma vez para cada item previamente selecionado e uma vez para o item recém-selecionado.

Para determinar quais os itens selecionados no ListView controlo, use a SelectedItems propriedade para aceder ao ListView.SelectedListViewItemCollection. Pode criar um gestor de eventos para este evento realizar tarefas sempre que houver uma alteração nos itens selecionados no ListView controlo.

Para obter mais informações sobre como manipular eventos, consulte Manipulando e gerando eventos.

Ver também

• ItemSelectionChanged
• OnSelectedIndexChanged(EventArgs)
• EventHandler
• SelectedIndices
• SelectedItems