ListView.CheckedItems Свойство

Определение

Возвращает составляющие элементы с установленными в настоящий момент флажками в элементе управления.

public:
 property System::Windows::Forms::ListView::CheckedListViewItemCollection ^ CheckedItems { System::Windows::Forms::ListView::CheckedListViewItemCollection ^ get(); };
[System.ComponentModel.Browsable(false)]
public System.Windows.Forms.ListView.CheckedListViewItemCollection CheckedItems { get; }
[<System.ComponentModel.Browsable(false)>]
member this.CheckedItems : System.Windows.Forms.ListView.CheckedListViewItemCollection
Public ReadOnly Property CheckedItems As ListView.CheckedListViewItemCollection

Значение свойства

ListView.CheckedListViewItemCollection

Коллекция ListView.CheckedListViewItemCollection, содержащая элементы с установленными в данный момент флажками. Если в данный момент таких элементов нет, возвращается пустая коллекция ListView.CheckedListViewItemCollection.

Атрибуты

Примеры

В следующем примере кода демонстрируется проверка ListView , которая обрабатывает ItemChecked событие. В примере свойство используется CheckedItems для подсчета новой цены при каждом проверке или снятии элемента. Чтобы запустить этот пример, вставьте следующий код в форму, содержащую именованный ListView ListView1 и именованный Textbox1TextBox . Вызовите InitializeListView метод из конструктора или Load метода формы.

void InitializeListView()
{
   this->ListView1 = gcnew System::Windows::Forms::ListView;
   
   // Set properties such as BackColor and DockStyle and Location.
   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->Size = System::Drawing::Size( 292, 130 );
   this->ListView1->View = System::Windows::Forms::View::Details;
   this->ListView1->HideSelection = false;
   
   // Allow the user to select multiple items.
   this->ListView1->MultiSelect = true;
   
   // Show CheckBoxes in the ListView.
   this->ListView1->CheckBoxes = true;
   
   //Set the column headers and populate the columns.
   ListView1->HeaderStyle = ColumnHeaderStyle::Nonclickable;
   ColumnHeader^ columnHeader1 = gcnew ColumnHeader;
   columnHeader1->Text = "Breakfast Choices";
   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","2.79","2.09","2.69"};
   int count;
   
   // Members are added one at a time, so call BeginUpdate to ensure 
   // the list is painted only once, rather than as each list item is added.
   ListView1->BeginUpdate();
   for ( count = 0; count < foodList->Length; count++ )
   {
      ListViewItem^ listItem = gcnew ListViewItem( foodList[ count ] );
      listItem->SubItems->Add( foodPrice[ count ] );
      ListView1->Items->Add( listItem );
   }
   
   //Call EndUpdate when you finish adding items to the ListView.
   ListView1->EndUpdate();
   this->Controls->Add( this->ListView1 );
}
private void InitializeListView()
{
    this.ListView1 = new System.Windows.Forms.ListView();

    // Set properties such as BackColor and DockStyle and Location.
    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.Size = new System.Drawing.Size(292, 130);
    this.ListView1.View = System.Windows.Forms.View.Details;
    this.ListView1.HideSelection = false;

    // Allow the user to select multiple items.
    this.ListView1.MultiSelect = true;

    // Show CheckBoxes in the ListView.
    this.ListView1.CheckBoxes = true;
    
    //Set the column headers and populate the columns.
    ListView1.HeaderStyle = ColumnHeaderStyle.Nonclickable;
    
    ColumnHeader columnHeader1 = new ColumnHeader();
    columnHeader1.Text = "Breakfast Choices";
    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", 
        "2.79", "2.09", "2.69"};
    
    int count;

    // Members are added one at a time, so call BeginUpdate to ensure 
    // the list is painted only once, rather than as each list item is added.
    ListView1.BeginUpdate();

    for(count = 0; count < foodList.Length; count++)
    {
        ListViewItem listItem = new ListViewItem(foodList[count]);
        listItem.SubItems.Add(foodPrice[count]);
        ListView1.Items.Add(listItem);
    }

    //Call EndUpdate when you finish adding items to the ListView.
    ListView1.EndUpdate();
    this.Controls.Add(this.ListView1);
}
Private Sub InitializeListView()
    Me.ListView1 = New System.Windows.Forms.ListView

    ' Set properties such as BackColor, Location and Size
    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.Size = New System.Drawing.Size(292, 130)
    Me.ListView1.View = System.Windows.Forms.View.Details
    Me.ListView1.HideSelection = False

    ' Allow user to select multiple items.
    Me.ListView1.MultiSelect = True

    ' Show check boxes in the ListView.
    Me.ListView1.CheckBoxes = True

    'Set the column headers and populate the columns.
    ListView1.HeaderStyle = ColumnHeaderStyle.Nonclickable
    Dim columnHeader1 As New ColumnHeader
    With columnHeader1
        .Text = "Breakfast Choices"
        .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", _
        "2.79", "2.09", "2.69"}
    Dim count As Integer

    ' Members are added one at a time, so call BeginUpdate to ensure 
    ' the list is painted only once, rather than as each list item is added.
    ListView1.BeginUpdate()

    For count = 0 To foodList.Length - 1
        Dim listItem As New ListViewItem(foodList(count))
        listItem.SubItems.Add(foodPrice(count))
        ListView1.Items.Add(listItem)
    Next

    'Call EndUpdate when you finish adding items to the ListView.
    ListView1.EndUpdate()
    Me.Controls.Add(Me.ListView1)
End Sub
// Handles the ItemChecked event.  The method loops through all the 
// checked items and tallies a new price each time an item is 
// checked or unchecked. It outputs the price to TextBox1.
void ListView1_ItemCheck2( Object^ /*sender*/, System::Windows::Forms::ItemCheckEventArgs^ e )
{
   double price = 0.0;
   ListView::CheckedListViewItemCollection^ checkedItems = ListView1->CheckedItems;
   System::Collections::IEnumerator^ myEnum = checkedItems->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      ListViewItem^ item = safe_cast<ListViewItem^>(myEnum->Current);
      price += Double::Parse( item->SubItems[ 1 ]->Text );
   }

   if ( e->CurrentValue == CheckState::Unchecked )
   {
      price += Double::Parse( this->ListView1->Items[ e->Index ]->SubItems[ 1 ]->Text );
   }
   else
   if ( (e->CurrentValue == CheckState::Checked) )
   {
      price -= Double::Parse( this->ListView1->Items[ e->Index ]->SubItems[ 1 ]->Text );
   }

   // Output the price to TextBox1.
   TextBox1->Text = price.ToString();
}
// Handles the ItemChecked event.  The method loops through all the 
// checked items and tallies a new price each time an item is 
// checked or unchecked. It outputs the price to TextBox1.
private void ListView1_ItemCheck2(object sender, 
    System.Windows.Forms.ItemCheckEventArgs e)
{
    double price = 0.0;
    ListView.CheckedListViewItemCollection checkedItems = 
        ListView1.CheckedItems;
    
    foreach ( ListViewItem item in checkedItems )
    {
        price += Double.Parse(item.SubItems[1].Text);
    }
    if (e.CurrentValue==CheckState.Unchecked)
    {
        price += Double.Parse(
            this.ListView1.Items[e.Index].SubItems[1].Text);
    }
    else if((e.CurrentValue==CheckState.Checked))
    {
        price -= Double.Parse(
            this.ListView1.Items[e.Index].SubItems[1].Text);
    }
    // Output the price to TextBox1.
    TextBox1.Text = price.ToString();
}
' Handles the ItemCheck event.  The method loops through all the 
' checked items and tallies a new price each time an item is 
' checked or unchecked. It outputs the price to TextBox1.
Private Sub ListView1_ItemCheck2(ByVal sender As Object, _
    ByVal e As System.Windows.Forms.ItemCheckEventArgs) _
    Handles ListView1.ItemCheck

    Dim item As ListViewItem
    Dim price As Double = 0.0
    Dim checkedItems As ListView.CheckedListViewItemCollection = _
        ListView1.CheckedItems
    For Each item In checkedItems
        price += Double.Parse(item.SubItems(1).Text)
    Next
    If (e.CurrentValue = CheckState.Unchecked) Then
        price += Double.Parse(Me.ListView1.Items(e.Index).SubItems(1).Text)
    ElseIf (e.CurrentValue = CheckState.Checked) Then
        price -= Double.Parse(Me.ListView1.Items(e.Index).SubItems(1).Text)
    End If

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

Комментарии

Это свойство полезно только в CheckBoxes том случае, если свойству ListView элемента управления присвоено значение true. Свойство CheckedItems возвращает коллекцию, содержащую все элементы, которые проверяются в элементе управления. Дополнительные сведения о том, как управлять элементами в коллекции, см. в разделе ListView.CheckedListViewItemCollection.

Если вы хотите получить коллекцию позиций индекса в ListView.ListViewItemCollection элементах, которые проверяются в элементе ListView управления, вместо проверяемых элементов используйте CheckedIndices свойство.

Применяется к

См. также раздел