ItemCheckEventArgs.CurrentValue Property
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Gets a value indicating the current state of the item's check box.
public:
property System::Windows::Forms::CheckState CurrentValue { System::Windows::Forms::CheckState get(); };
public System.Windows.Forms.CheckState CurrentValue { get; }
member this.CurrentValue : System.Windows.Forms.CheckState
Public ReadOnly Property CurrentValue As CheckState
One of the CheckState values.
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 InitializeListView
method from the form's constructor or Load
method. 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
This property enables you to determine the check state of the specified item in the CheckedListBox before the check state change to apply is made.
Termék | Verziók |
---|---|
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
Windows Desktop | 3.0, 3.1, 5, 6, 7, 8, 9 |
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