ListView::ItemCheck Event

Occurs when the check state of an item changes.

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

public:
 event ItemCheckEventHandler^ ItemCheck {
	void add (ItemCheckEventHandler^ value);
	void remove (ItemCheckEventHandler^ value);
}

The CheckBoxes property must be set to true in order for check boxes to be displayed next to each item in the ListView control. The ItemCheck event occurs when the check state of an item changes or when the CheckBoxes property is set to true. You can create an event handler for the ItemCheck event to perform tasks such as changing the state of an item's icon or another application-specific task each time an item is checked in the ListView control.

NoteNote

If the window handle has not been created when the ItemCheck event is raised, the event will be delayed. Once the window handle is created (when the form is shown), any delayed ItemCheck events will be raised. For more information, see HandleCreated.

For more information about handling events, see Handling and Raising Events.

The following code example demonstrates a checked ListView control that handles the ItemCheck event. The method uses the ItemCheckEventArgs::CurrentValue and ItemCheckEventArgs::Index properties to retrieve and tally the price of the menu items selected. To run this example, paste the following code into a form containing a ListView named ListView1 and a TextBox named Textbox1. Call the InititalizeListView method from the form's constructor or Load method. Ensure that the ItemCheck event is associated with the event handler in this example.

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 );
}


...


double price;

// Handles the ItemCheck event. The method uses the CurrentValue 
// property of the ItemCheckEventArgs to retrieve and tally the   
// price of the menu items selected.   
void ListView1_ItemCheck1( Object^ /*sender*/, System::Windows::Forms::ItemCheckEventArgs^ e )
{
   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();
}

.NET Framework

Supported in: 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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