ListView.Clear 方法
从控件中移除所有项和列。
**命名空间:**System.Windows.Forms
**程序集:**System.Windows.Forms（在 system.windows.forms.dll 中）
语法
声明
Public Sub Clear
用法
Dim instance As ListView
instance.Clear
public void Clear ()
public:
void Clear ()
public void Clear ()
public function Clear ()
备注
您可以使用此方法从 ListView 控件中移除所有的项和列，而不必从 ListView.ColumnHeaderCollection 和 ListView.ListViewItemCollection 类中调用各个 Clear 方法。
提示
Clear 方法不清除为 ListView 控件指定的 Groups。若要清除 Groups，请调用 ListViewGroupCollection.Clear。
示例
下面的代码示例演示了 Clear 和 ListViewItem.Selected 成员的使用方法。若要运行此示例，请将以下代码粘贴到一个窗体中，该窗体包含一个名为 ListView1 的 ListView 和一个靠近窗体底部的名为 Button1 的按钮。从窗体的构造函数或 Load 方法调用 InitializeListView 方法。
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
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:
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.set_Dock(DockStyle.Top);
this.listView1.set_Location(new System.Drawing.Point(0, 0));
this.listView1.set_Size(new System.Drawing.Size(292, 130));
this.listView1.set_View(View.Details);
this.listView1.set_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);
} //InitializeListView
private void PopulateMenu(String meal,String menuItems[],String menuPrices[])
{
ColumnHeader columnHeader1 = new ColumnHeader();
columnHeader1.set_Text(meal + " Choices");
columnHeader1.set_TextAlign(HorizontalAlignment.Left);
columnHeader1.set_Width(146);
ColumnHeader columnHeader2 = new ColumnHeader();
columnHeader2.set_Text("Price");
columnHeader2.set_TextAlign(HorizontalAlignment.Center);
columnHeader2.set_Width(142);
this.listView1.get_Columns().Add(columnHeader1);
this.listView1.get_Columns().Add(columnHeader2);
for (int count = 0; count < menuItems.length; count++) {
ListViewItem listItem =
new ListViewItem((String)menuItems.get_Item(count));
listItem.get_SubItems().Add((String)menuPrices.get_Item(count));
listView1.get_Items().Add(listItem);
}
// Use the Selected property to select the first item on
// the list.
listView1.Focus();
listView1.get_Items().get_Item(0).set_Selected(true);
} //PopulateMenu
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.set_Enabled(false);
} //button1_Click
平台
Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition
.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。
版本信息
.NET Framework
受以下版本支持：2.0、1.1、1.0
.NET Compact Framework
受以下版本支持：2.0、1.0
请参见
参考
ListView 类
ListView 成员
System.Windows.Forms 命名空间
ListView.ColumnHeaderCollection.Clear
ListView.ListViewItemCollection.Clear