ListView.Clear Method

Reference

Definition

Namespace:: System.Windows.Forms

Assembly:: System.Windows.Forms.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Removes all items and columns from the control.

public:
 void Clear();

public void Clear ();

member this.Clear : unit -> unit

Public Sub Clear ()

Examples

The following code example demonstrates the use of Clear and ListViewItem.Selected members. To run this example, paste the following code into a form that contains a ListView named ListView1 and a button, located toward the bottom of the form, named Button1. Call the InitializeListView method from the form's constructor or Load method.

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

Remarks

You can use this method to remove all items and columns from the ListView control without having to call the individual Clear methods from the ListView.ColumnHeaderCollection and ListView.ListViewItemCollection classes.

Note

The Clear method does not clear Groups specified for the ListView control. To clear Groups call ListViewGroupCollection.Clear.

Applies to

Delen via

ListView.Clear Method

Definition

Examples

Remarks

Applies to

See also

Aanvullende resources