ListView.Clear Method
Definition
Important
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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
See also
.NET