ListView.ItemCheck 事件
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
当某项的选中状态更改时发生。
public:
event System::Windows::Forms::ItemCheckEventHandler ^ ItemCheck;
public event System.Windows.Forms.ItemCheckEventHandler ItemCheck;
public event System.Windows.Forms.ItemCheckEventHandler? ItemCheck;
member this.ItemCheck : System.Windows.Forms.ItemCheckEventHandler
Public Custom Event ItemCheck As ItemCheckEventHandler
事件类型
示例
下面的代码示例演示了一个用于处理 事件的选中 ListView 控件 ItemCheck 。 方法使用 ItemCheckEventArgs.CurrentValue 和 ItemCheckEventArgs.Index 属性来检索和计算所选菜单项的价格。 若要运行此示例,请将以下代码粘贴到包含 ListView
名为 ListView1
和 TextBox
的 Textbox1
窗体中。 InitializeListView
从窗体的构造函数或Load
方法调用 方法。 确保事件 ItemCheck 与此示例中的事件处理程序相关联。
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
注解
属性CheckBoxes必须设置为 true,才能在控件中的每个项ListView旁边显示检查框。 当ItemCheck项的检查状态更改或 属性设置为 true
时CheckBoxes,会发生 该事件。 你可以为 ItemCheck 事件创建事件处理程序以执行任务,例如,每次在控件中 ListView 签入某个项时更改项图标或其他特定于应用程序的任务的状态。
注意
如果在引发事件时 ItemCheck 尚未创建窗口句柄,则将延迟该事件。 在窗体) 显示 (创建窗口句柄后,将引发任何延迟 ItemCheck 事件。 有关详细信息,请参阅 HandleCreated。
有关处理事件的详细信息,请参阅 处理和引发事件。
适用于
另请参阅
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