ListView.EndUpdate 方法
定义
重要
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在 BeginUpdate() 方法挂起描述后,继续描述列表视图控件。
public:
void EndUpdate();
public void EndUpdate ();
member this.EndUpdate : unit -> unit
Public Sub EndUpdate ()
示例
下面的代码示例演示如何初始化 ListView 控件以包含复选框。 它还演示了如何使用 BeginUpdate 和 EndUpdate 方法。 若要运行此示例,请将以下代码粘贴到包含名为 ListView1
的ListView窗体中。
InitializeListView
从窗体的构造函数或 Load
方法调用 方法。
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
注解
将多个项添加到 ListView 的首选方法是使用AddRange通过 Items) 的 ListView 属性访问 (的方法ListView.ListViewItemCollection。 这使你能够在单个操作中将项数组添加到列表中。 但是,如果要使用 Add 类的 ListView.ListViewItemCollection 方法一次添加一个项,则可以使用 BeginUpdate 方法防止控件在每次添加项时重新绘制 ListView 。 完成向控件添加项的任务后,调用 EndUpdate 方法以启用 ListView 重新绘制。 向控件添加大量项时,这种添加项的方式可以防止 闪烁绘制 ListView 。
如果 BeginUpdate 多次调用 , EndUpdate 则必须调用等效的次数。 直到上次调用 EndUpdate 时, ListView 不会重新绘制。 除此之外,对 的多个调用 BeginUpdate 都不起作用。