ListView.Clear Methode

public:
 void Clear();

public void Clear();

member this.Clear : unit -> unit

Public Sub Clear ()

Voorbeelden

In het volgende codevoorbeeld ziet u het gebruik van Clear en ListViewItem.Selected leden. Als u dit voorbeeld wilt uitvoeren, plakt u de volgende code in een formulier dat een ListView benoemde ListView1 en een knop bevat, die zich onder aan het formulier bevindt, met de naam Button1. Roep de methode aan vanuit de InitializeListView constructor of Load methode van het formulier.

private:
   void InitializeListView()
   {
      // Set up the inital values for the ListView and populate it.
      this->ListView1 = gcnew ListView;
      this->ListView1->Dock = DockStyle::Top;
      this->ListView1->Location = System::Drawing::Point( 0, 0 );
      this->ListView1->Size = System::Drawing::Size( 292, 130 );
      this->ListView1->View = View::Details;
      this->ListView1->FullRowSelect = true;
      array<String^>^breakfast = {"Continental Breakfast","Pancakes and Sausage","Denver Omelet","Eggs & Bacon","Bagel & Cream Cheese"};
      array<String^>^breakfastPrices = {"3.09","4.09","4.19","4.79","2.09"};
      PopulateMenu( "Breakfast", breakfast, breakfastPrices );
   }

   void PopulateMenu( String^ meal, array<String^>^menuItems, array<String^>^menuPrices )
   {
      ColumnHeader^ columnHeader1 = gcnew ColumnHeader;
      columnHeader1->Text = String::Concat( meal, " Choices" );
      columnHeader1->TextAlign = HorizontalAlignment::Left;
      columnHeader1->Width = 146;
      ColumnHeader^ columnHeader2 = gcnew ColumnHeader;
      columnHeader2->Text = "Price";
      columnHeader2->TextAlign = HorizontalAlignment::Center;
      columnHeader2->Width = 142;
      this->ListView1->Columns->Add( columnHeader1 );
      this->ListView1->Columns->Add( columnHeader2 );
      for ( int count = 0; count < menuItems->Length; count++ )
      {
         ListViewItem^ listItem = gcnew ListViewItem( menuItems[ count ] );
         listItem->SubItems->Add( menuPrices[ count ] );
         ListView1->Items->Add( listItem );

      }
      
      // Use the Selected property to select the first item on 
      // the list.
      ListView1->Focus();
      ListView1->Items[ 0 ]->Selected = true;
   }

   void Button1_Click( System::Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      // Create new values for the ListView, clear the list, 
      // and repopulate it.
      array<String^>^lunch = {"Hamburger","Grilled Cheese","Soup & Salad","Club Sandwich","Hotdog"};
      array<String^>^lunchPrices = {"4.09","5.09","5.19","4.79","2.09"};
      ListView1->Clear();
      PopulateMenu( "Lunch", lunch, lunchPrices );
      Button1->Enabled = false;
   }

private void InitializeListView()
{
    // Set up the inital values for the ListView and populate it.
    this.ListView1 = new ListView();
    this.ListView1.Dock = DockStyle.Top;
    this.ListView1.Location = new System.Drawing.Point(0, 0);
    this.ListView1.Size = new System.Drawing.Size(292, 130);
    this.ListView1.View = View.Details;
    this.ListView1.FullRowSelect = true;

    string[] breakfast = new string[]{"Continental Breakfast", 
        "Pancakes and Sausage", "Denver Omelet", "Eggs & Bacon", 
        "Bagel & Cream Cheese"};

    string[] breakfastPrices = new string[]{"3.09", "4.09", 
        "4.19", "4.79", "2.09"};

    PopulateMenu("Breakfast", breakfast, breakfastPrices);
}

private void PopulateMenu(string meal, 
    string[] menuItems, string[] menuPrices)
{
    ColumnHeader columnHeader1 = new ColumnHeader();
    columnHeader1.Text = meal + " Choices";
    columnHeader1.TextAlign = HorizontalAlignment.Left;
    columnHeader1.Width = 146;

    ColumnHeader columnHeader2 = new ColumnHeader();
    columnHeader2.Text = "Price";
    columnHeader2.TextAlign = HorizontalAlignment.Center;
    columnHeader2.Width = 142;

    this.ListView1.Columns.Add(columnHeader1);
    this.ListView1.Columns.Add(columnHeader2);

    for(int count=0; count < menuItems.Length; count++)
    {
        ListViewItem listItem = 
            new ListViewItem(menuItems[count]);
        listItem.SubItems.Add(menuPrices[count]);
        ListView1.Items.Add(listItem);
    }

    // Use the Selected property to select the first item on 
    // the list.
    ListView1.Focus();
    ListView1.Items[0].Selected = true;
}

private void Button1_Click(System.Object sender, System.EventArgs e)
{
    // Create new values for the ListView, clear the list, 
    // and repopulate it.
    string[] lunch = new string[]{"Hamburger", "Grilled Cheese",
        "Soup & Salad", "Club Sandwich", "Hotdog"};

    string[] lunchPrices = new string[]{"4.09", "5.09", "5.19", 
        "4.79", "2.09"};

    ListView1.Clear();

    PopulateMenu("Lunch", lunch, lunchPrices);
    Button1.Enabled = false;
}

Private Sub InitializeListView()

    ' Set up the inital values for the ListView and populate it.
    Me.ListView1 = New ListView
    Me.ListView1.Dock = DockStyle.Top
    Me.ListView1.Location = New System.Drawing.Point(0, 0)
    Me.ListView1.Size = New System.Drawing.Size(292, 130)
    Me.ListView1.View = View.Details
    Me.ListView1.FullRowSelect = True

    Dim breakfast() As String = New String() {"Continental Breakfast", "Pancakes and Sausage", _
   "Denver Omelet", "Eggs & Bacon", "Bagel & Cream Cheese"}

    Dim breakfastPrices() As String = New String() {"3.09", "4.09", "4.19", _
       "4.79", "2.09"}

    PopulateMenu("Breakfast", breakfast, breakfastPrices)
End Sub

Private Sub PopulateMenu(ByVal meal As String, _
    ByVal menuItems() As String, ByVal menuPrices() As String)
    Dim columnHeader1 As New ColumnHeader
    With columnHeader1
        .Text = meal & " Choices"
        .TextAlign = HorizontalAlignment.Left
        .Width = 146
    End With
    Dim columnHeader2 As New ColumnHeader
    With columnHeader2
        .Text = "Price"
        .TextAlign = HorizontalAlignment.Center
        .Width = 142
    End With
    Me.ListView1.Columns.Add(columnHeader1)
    Me.ListView1.Columns.Add(columnHeader2)

    Dim count As Integer

    For count = 0 To menuItems.Length - 1
        Dim listItem As New ListViewItem(menuItems(count))
        listItem.SubItems.Add(menuPrices(count))
        ListView1.Items.Add(listItem)
    Next

    ' Use the Selected property to select the first item on 
    ' the list.
    ListView1.Focus()
    ListView1.Items(0).Selected = True
End Sub


Private Sub Button1_Click(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles Button1.Click

    ' Create new values for the ListView, clear the list, 
    ' and repopulate it.
    Dim lunch() As String = New String() {"Hamburger", _ 
        "Grilled Cheese", "Soup & Salad", "Club Sandwich", "Hotdog"}

    Dim lunchPrices() As String = New String() {"4.09", "5.09", _
        "5.19", "4.79", "2.09"}

    ListView1.Clear()

    PopulateMenu("Lunch", lunch, lunchPrices)
    Button1.Enabled = False
End Sub

Opmerkingen

U kunt deze methode gebruiken om alle items en kolommen uit het ListView besturingselement te verwijderen zonder dat u de afzonderlijke Clear methoden uit de ListView.ColumnHeaderCollection en ListView.ListViewItemCollection klassen hoeft aan te roepen.

Zie ook

• Clear()
• Clear()