ItemCheckEventArgs Class
Assembly: System.Windows.Forms (in system.windows.forms.dll)
'Declaration <ComVisibleAttribute(True)> _ Public Class ItemCheckEventArgs Inherits EventArgs 'Usage Dim instance As ItemCheckEventArgs
/** @attribute ComVisibleAttribute(true) */ public class ItemCheckEventArgs extends EventArgs
ComVisibleAttribute(true) public class ItemCheckEventArgs extends EventArgs
The ItemCheck event occurs when the checked state of an item in a checked list box changes. 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.
For more information about handling events, see Consuming Events.
The following code example demonstrates a checked ListView control that handles the ListView.ItemChecked event. The method uses the CurrentValue and Index properties of the ItemCheckEventArgs object to retrieve and tally the price of the menu items selected. To run this example paste the following code in 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 all events are associated with their event-handling methods.
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
... 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
private void InitializeListView()
{
this.listView1 = new System.Windows.Forms.ListView();
// Set properties such as BackColor and DockStyle and Location.
this.listView1.set_BackColor(System.Drawing.SystemColors.get_Control());
this.listView1.set_Dock(System.Windows.Forms.DockStyle.Top);
this.listView1.set_Location(new System.Drawing.Point(0, 0));
this.listView1.set_Size(new System.Drawing.Size(292, 130));
this.listView1.set_View(System.Windows.Forms.View.Details);
this.listView1.set_HideSelection(false);
// Allow the user to select multiple items.
this.listView1.set_MultiSelect(true);
// Show CheckBoxes in the ListView.
this.listView1.set_CheckBoxes(true);
//Set the column headers and populate the columns.
listView1.set_HeaderStyle(ColumnHeaderStyle.Nonclickable);
ColumnHeader columnHeader1 = new ColumnHeader();
columnHeader1.set_Text("Breakfast Choices");
columnHeader1.set_TextAlign(HorizontalAlignment.Left);
columnHeader1.set_Width(146);
ColumnHeader columnHeader2 = new ColumnHeader();
columnHeader2.set_Text("Price Each");
columnHeader2.set_TextAlign(HorizontalAlignment.Center);
columnHeader2.set_Width(142);
this.listView1.get_Columns().Add(columnHeader1);
this.listView1.get_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((String)foodList.get_Item(count));
listItem.get_SubItems().Add((String)foodPrice.get_Item(count));
listView1.get_Items().Add(listItem);
}
//Call EndUpdate when you finish adding items to the ListView.
listView1.EndUpdate();
this.get_Controls().Add(this.listView1);
} //InitializeListView
... private 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.get_CurrentValue().Equals(CheckState.Unchecked)) {
price += System.Double.Parse(
this.listView1.get_Items().get_Item(e.get_Index()).
get_SubItems().get_Item(1).get_Text());
}
else {
if (e.get_CurrentValue().Equals(CheckState.Checked)) {
price -= System.Double.Parse(this.listView1.get_Items().
get_Item(e.get_Index()).get_SubItems().get_Item(1).
get_Text());
}
}
// Output the price to TextBox1.
textBox1.set_Text(((System.Double)price).ToString());
} //listView1_ItemCheck1
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.