ItemCheckEventArgs ItemCheckEventArgs ItemCheckEventArgs ItemCheckEventArgs Class

Определение

Предоставляет данные для ItemCheck событие CheckedListBox и ListView элементов управления.Provides data for the ItemCheck event of the CheckedListBox and ListView controls.

public ref class ItemCheckEventArgs : EventArgs
[System.Runtime.InteropServices.ComVisible(true)]
public class ItemCheckEventArgs : EventArgs
type ItemCheckEventArgs = class
    inherit EventArgs
Public Class ItemCheckEventArgs
Inherits EventArgs
Наследование
ItemCheckEventArgsItemCheckEventArgsItemCheckEventArgsItemCheckEventArgs
Атрибуты

Примеры

В следующем примере кода показано, извлеченный ListView управления, обрабатывающий ListView.ItemCheck событий.The following code example demonstrates a checked ListView control that handles the ListView.ItemCheck event. Данный метод использует CurrentValue и Index свойства ItemCheckEventArgs объекта для извлечения и регистрировались цена выбранных элементов меню.The method uses the CurrentValue and Index properties of the ItemCheckEventArgs object to retrieve and tally the price of the menu items selected. Чтобы выполнить этот пример, вставьте следующий код в форму, содержащую ListView с именем ListView1 и TextBox с именем Textbox1.To run this example paste the following code in a form containing a ListView named ListView1 and a TextBox named Textbox1. Вызовите InitializeListView метод из конструктора формы или Load метод.Call the InitializeListView method from the form's constructor or Load method. Убедитесь, что все события связаны с их методов обработки событий.Ensure all events are associated with their event-handling methods.

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
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();
}
double price = 0.0;

// Handles the ItemCheck event. The method uses the CurrentValue
// property of the ItemCheckEventArgs to retrieve and tally the  
// price of the menu items selected.  
private 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();
}
Dim price As Double = 0.0

' Handles the ItemChecked event. The method uses the CurrentValue property 
' of the ItemCheckEventArgs to retrieve and tally the price of the menu 
' items selected.  
Private Sub ListView1_ItemCheck1(ByVal sender As Object, _
    ByVal e As System.Windows.Forms.ItemCheckEventArgs) _
    Handles ListView1.ItemCheck

    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

ItemCheck Событие возникает при изменении состояния флажка элемента в выбранном списке.The ItemCheck event occurs when the checked state of an item in a checked list box changes. ItemCheckEventArgs Класс указывает индекс элемента для изменения, текущее значение поля с флажком для элемента и новое значение, задаваемое для флажка.The ItemCheckEventArgs class specifies the index of the item to change, the current value of the check box for the item, and the new value to set for the check box.

Дополнительные сведения об обработке событий см. в разделе обработка и вызов событий.For more information about handling events, see Handling and Raising Events.

Конструкторы

ItemCheckEventArgs(Int32, CheckState, CheckState) ItemCheckEventArgs(Int32, CheckState, CheckState) ItemCheckEventArgs(Int32, CheckState, CheckState) ItemCheckEventArgs(Int32, CheckState, CheckState)

Инициализирует новый экземпляр класса ItemCheckEventArgs.Initializes a new instance of the ItemCheckEventArgs class.

Свойства

CurrentValue CurrentValue CurrentValue CurrentValue

Возвращает значение, указывающее текущее состояние флажка элемента.Gets a value indicating the current state of the item's check box.

Index Index Index Index

Возвращает начинающийся с нуля индекс изменяемого элемента.Gets the zero-based index of the item to change.

NewValue NewValue NewValue NewValue

Возвращает или задает значение, определяющее состояния флажка элемента: установлен, не установлен или неопределенное состояние.Gets or sets a value indicating whether to set the check box for the item to be checked, unchecked, or indeterminate.

Методы

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

Определяет, равен ли заданный объект текущему объекту.Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

Служит хэш-функцией по умолчанию.Serves as the default hash function.

(Inherited from Object)
GetType() GetType() GetType() GetType()

Возвращает объект Type для текущего экземпляра.Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Создает неполную копию текущего объекта Object.Creates a shallow copy of the current Object.

(Inherited from Object)
ToString() ToString() ToString() ToString()

Возвращает строку, представляющую текущий объект.Returns a string that represents the current object.

(Inherited from Object)

Применяется к

Дополнительно