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ListView.ItemCheck Kejadian

  • Referensi

Definisi

Ruang nama:
System.Windows.Forms
Rakitan:
System.Windows.Forms.dll

Terjadi ketika status pemeriksaan item berubah.

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

Jenis Acara

ItemCheckEventHandler

Contoh

Contoh kode berikut menunjukkan kontrol yang dicentang ListView yang menangani ItemCheck peristiwa. Metode ini menggunakan ItemCheckEventArgs.CurrentValue properti dan ItemCheckEventArgs.Index untuk mengambil dan mengikat harga item menu yang dipilih. Untuk menjalankan contoh ini, tempelkan kode berikut ke dalam formulir yang ListView berisi bernama ListView1 dan bernama TextBoxTextbox1. InitializeListView Panggil metode dari konstruktor atau Load metode formulir. Pastikan bahwa peristiwa dikaitkan ItemCheck dengan penanganan aktivitas dalam contoh ini.

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

Keterangan

Properti CheckBoxes harus diatur ke true agar kotak centang ditampilkan di samping setiap item dalam ListView kontrol. Peristiwa ItemCheck terjadi ketika status pemeriksaan item berubah atau ketika CheckBoxes properti diatur ke true. Anda dapat membuat penanganan aktivitas untuk kejadian guna ItemCheck melakukan tugas seperti mengubah status ikon item atau tugas khusus aplikasi lainnya setiap kali item dicentang dalam ListView kontrol.

Catatan

Jika handel jendela belum dibuat saat ItemCheck peristiwa dinaikkan, peristiwa akan tertunda. Setelah handel jendela dibuat (ketika formulir ditampilkan), setiap peristiwa yang tertunda ItemCheck akan dinaikkan. Untuk informasi selengkapnya, lihat HandleCreated.

Untuk informasi selengkapnya tentang menangani peristiwa, lihat Menangani dan Menaikkan Peristiwa.

Berlaku untuk

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