ListViewGroup Class
Definition
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.
Represents a group of items displayed within a ListView control.
public ref class ListViewGroup sealed : System::Runtime::Serialization::ISerializable[System.ComponentModel.TypeConverter(typeof(System.Windows.Forms.ListViewGroupConverter))]
[System.Serializable]
public sealed class ListViewGroup : System.Runtime.Serialization.ISerializable[<System.ComponentModel.TypeConverter(typeof(System.Windows.Forms.ListViewGroupConverter))>]
[<System.Serializable>]
type ListViewGroup = class
interface ISerializablePublic NotInheritable Class ListViewGroup
Implements ISerializable- Inheritance
-
ListViewGroup
- Attributes
- Implements
Examples
The following code example demonstrates how to use the ListView grouping feature to organize items by subitem value in the details view. This form of grouping is similar to the grouping used in Windows Explorer. In the example, the groups are created dynamically. For each subitem column, one group is created for each unique subitem value. For the parent item column, one group is created for each unique initial letter. Clicking the header of a column sorts the items into the groups created for that column. Clicking the same column header again reverses the order of the groups.
#using <mscorlib.dll>
#using <System.Drawing.dll>
#using <System.dll>
#using <System.Windows.Forms.dll>
using namespace System;
using namespace System::Collections;
using namespace System::Windows::Forms;
public ref class ListViewGroupsExample : public Form
{
private:
ListView^ myListView;
bool isRunningXPOrLater;
// Declare a Hashtable array in which to store the groups.
array<Hashtable^>^ groupTables;
// Declare a variable to store the current grouping column.
int groupColumn;
public:
ListViewGroupsExample()
{
groupColumn = 0;
// Initialize myListView.
myListView = gcnew ListView();
myListView->Dock = DockStyle::Fill;
myListView->View = View::Details;
myListView->Sorting = SortOrder::Ascending;
// Create and initialize column headers for myListView.
ColumnHeader^ columnHeader0 = gcnew ColumnHeader();
columnHeader0->Text = "Title";
columnHeader0->Width = -1;
ColumnHeader^ columnHeader1 = gcnew ColumnHeader();
columnHeader1->Text = "Author";
columnHeader1->Width = -1;
ColumnHeader^ columnHeader2 = gcnew ColumnHeader();
columnHeader2->Text = "Year";
columnHeader2->Width = -1;
// Add the column headers to myListView.
array<ColumnHeader^>^ temp0 = {columnHeader0, columnHeader1, columnHeader2};
myListView->Columns->AddRange(temp0);
// Add a handler for the ColumnClick event.
myListView->ColumnClick +=
gcnew ColumnClickEventHandler(this, &ListViewGroupsExample::myListView_ColumnClick);
// Create items and add them to myListView.
array<String^>^ temp1 = {"Programming Windows", "Petzold, Charles", "1998"};
ListViewItem^ item0 = gcnew ListViewItem( temp1 );
array<String^>^ temp2 = {"Code: The Hidden Language of Computer Hardware and Software",
"Petzold, Charles", "2000"};
ListViewItem^ item1 = gcnew ListViewItem( temp2 );
array<String^>^ temp3 = {"Programming Windows with C#", "Petzold, Charles", "2001"};
ListViewItem^ item2 = gcnew ListViewItem( temp3 );
array<String^>^ temp4 = {"Coding Techniques for Microsoft Visual Basic .NET",
"Connell, John", "2001"};
ListViewItem^ item3 = gcnew ListViewItem( temp4 );
array<String^>^ temp5 = {"C# for Java Developers", "Jones, Allen & Freeman, Adam",
"2002"};
ListViewItem^ item4 = gcnew ListViewItem( temp5 );
array<String^>^ temp6 = {"Microsoft .NET XML Web Services Step by Step",
"Jones, Allen & Freeman, Adam", "2002"};
ListViewItem^ item5 = gcnew ListViewItem( temp6 );
array<ListViewItem^>^ temp7 = {item0, item1, item2, item3, item4, item5};
myListView->Items->AddRange( temp7 );
// Determine whether Windows XP or a later
// operating system is present.
isRunningXPOrLater = false;
if (System::Environment::OSVersion->Version->Major > 5 ||
( System::Environment::OSVersion->Version->Major == 5 &&
System::Environment::OSVersion->Version->Minor >= 1) )
{
isRunningXPOrLater = true;
}
if (isRunningXPOrLater)
{
// Create the groupsTable array and populate it with one
// hash table for each column.
groupTables = gcnew array<Hashtable^>(myListView->Columns->Count);
for (int column = 0; column < myListView->Columns->Count; column++)
{
// Create a hash table containing all the groups
// needed for a single column.
groupTables[column] = CreateGroupsTable(column);
}
// Start with the groups created for the Title column.
SetGroups(0);
}
// Initialize the form.
this->Controls->Add(myListView);
this->Size = System::Drawing::Size(550, 330);
this->Text = "ListView Groups Example";
}
// Groups the items using the groups created for the clicked
// column.
private:
void myListView_ColumnClick(
Object^ /*sender*/, ColumnClickEventArgs^ e)
{
// Set the sort order to ascending when changing
// column groups; otherwise, reverse the sort order.
if ( myListView->Sorting == SortOrder::Descending ||
( isRunningXPOrLater && (e->Column != groupColumn) ) )
{
myListView->Sorting = SortOrder::Ascending;
}
else
{
myListView->Sorting = SortOrder::Descending;
}
groupColumn = e->Column;
// Set the groups to those created for the clicked column.
if (isRunningXPOrLater)
{
SetGroups(e->Column);
}
}
// Sets myListView to the groups created for the specified column.
private:
void SetGroups(int column)
{
// Remove the current groups.
myListView->Groups->Clear();
// Retrieve the hash table corresponding to the column.
Hashtable^ groups = dynamic_cast<Hashtable^>(groupTables[column]);
// Copy the groups for the column to an array.
array<ListViewGroup^>^ groupsArray = gcnew array<ListViewGroup^>(groups->Count);
groups->Values->CopyTo(groupsArray, 0);
// Sort the groups and add them to myListView.
Array::Sort(groupsArray, gcnew ListViewGroupSorter(myListView->Sorting));
myListView->Groups->AddRange(groupsArray);
// Iterate through the items in myListView, assigning each
// one to the appropriate group.
IEnumerator^ myEnum = myListView->Items->GetEnumerator();
while (myEnum->MoveNext())
{
ListViewItem^ item = safe_cast<ListViewItem^>(myEnum->Current);
// Retrieve the subitem text corresponding to the column.
String^ subItemText = item->SubItems[column]->Text;
// For the Title column, use only the first letter.
if (column == 0)
{
subItemText = subItemText->Substring(0, 1);
}
// Assign the item to the matching group.
item->Group = dynamic_cast<ListViewGroup^>(groups[subItemText]);
}
}
// Creates a Hashtable object with one entry for each unique
// subitem value (or initial letter for the parent item)
// in the specified column.
private:
Hashtable^ CreateGroupsTable(int column)
{
// Create a Hashtable object.
Hashtable^ groups = gcnew Hashtable();
// Iterate through the items in myListView.
IEnumerator^ myEnum1 = myListView->Items->GetEnumerator();
while (myEnum1->MoveNext())
{
ListViewItem^ item = safe_cast<ListViewItem^>(myEnum1->Current);
// Retrieve the text value for the column.
String^ subItemText = item->SubItems[column]->Text;
// Use the initial letter instead if it is the first column.
if (column == 0)
{
subItemText = subItemText->Substring(0, 1);
}
// If the groups table does not already contain a group
// for the subItemText value, add a new group using the
// subItemText value for the group header and Hashtable key.
if (!groups->Contains(subItemText))
{
groups->Add( subItemText, gcnew ListViewGroup(subItemText,
HorizontalAlignment::Left) );
}
}
// Return the Hashtable object.
return groups;
}
// Sorts ListViewGroup objects by header value.
ref class ListViewGroupSorter : public IComparer
{
private:
SortOrder order;
// Stores the sort order.
public:
ListViewGroupSorter(SortOrder theOrder)
{
order = theOrder;
}
// Compares the groups by header value, using the saved sort
// order to return the correct value.
virtual int Compare(Object^ x, Object^ y)
{
int result = String::Compare(
(dynamic_cast<ListViewGroup^>(x))->Header,
(dynamic_cast<ListViewGroup^>(y))->Header
);
if (order == SortOrder::Ascending)
{
return result;
}
else
{
return -result;
}
}
};
};
[STAThread]
int main()
{
Application::EnableVisualStyles();
Application::Run(gcnew ListViewGroupsExample());
}
using System;
using System.Collections;
using System.Windows.Forms;
public class ListViewGroupsExample : Form
{
private ListView myListView;
// Determine whether Windows XP or a later
// operating system is present.
private bool isRunningXPOrLater =
OSFeature.Feature.IsPresent(OSFeature.Themes);
// Declare a Hashtable array in which to store the groups.
private Hashtable[] groupTables;
// Declare a variable to store the current grouping column.
int groupColumn = 0;
public ListViewGroupsExample()
{
// Initialize myListView.
myListView = new ListView();
myListView.Dock = DockStyle.Fill;
myListView.View = View.Details;
myListView.Sorting = SortOrder.Ascending;
// Create and initialize column headers for myListView.
ColumnHeader columnHeader0 = new ColumnHeader();
columnHeader0.Text = "Title";
columnHeader0.Width = -1;
ColumnHeader columnHeader1 = new ColumnHeader();
columnHeader1.Text = "Author";
columnHeader1.Width = -1;
ColumnHeader columnHeader2 = new ColumnHeader();
columnHeader2.Text = "Year";
columnHeader2.Width = -1;
// Add the column headers to myListView.
myListView.Columns.AddRange(new ColumnHeader[]
{columnHeader0, columnHeader1, columnHeader2});
// Add a handler for the ColumnClick event.
myListView.ColumnClick +=
new ColumnClickEventHandler(myListView_ColumnClick);
// Create items and add them to myListView.
ListViewItem item0 = new ListViewItem( new string[]
{"Programming Windows",
"Petzold, Charles",
"1998"} );
ListViewItem item1 = new ListViewItem( new string[]
{"Code: The Hidden Language of Computer Hardware and Software",
"Petzold, Charles",
"2000"} );
ListViewItem item2 = new ListViewItem( new string[]
{"Programming Windows with C#",
"Petzold, Charles",
"2001"} );
ListViewItem item3 = new ListViewItem( new string[]
{"Coding Techniques for Microsoft Visual Basic .NET",
"Connell, John",
"2001"} );
ListViewItem item4 = new ListViewItem( new string[]
{"C# for Java Developers",
"Jones, Allen & Freeman, Adam",
"2002"} );
ListViewItem item5 = new ListViewItem( new string[]
{"Microsoft .NET XML Web Services Step by Step",
"Jones, Allen & Freeman, Adam",
"2002"} );
myListView.Items.AddRange(
new ListViewItem[] {item0, item1, item2, item3, item4, item5});
if (isRunningXPOrLater)
{
// Create the groupsTable array and populate it with one
// hash table for each column.
groupTables = new Hashtable[myListView.Columns.Count];
for (int column = 0; column < myListView.Columns.Count; column++)
{
// Create a hash table containing all the groups
// needed for a single column.
groupTables[column] = CreateGroupsTable(column);
}
// Start with the groups created for the Title column.
SetGroups(0);
}
// Initialize the form.
this.Controls.Add(myListView);
this.Size = new System.Drawing.Size(550, 330);
this.Text = "ListView Groups Example";
}
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.Run(new ListViewGroupsExample());
}
// Groups the items using the groups created for the clicked
// column.
private void myListView_ColumnClick(
object sender, ColumnClickEventArgs e)
{
// Set the sort order to ascending when changing
// column groups; otherwise, reverse the sort order.
if ( myListView.Sorting == SortOrder.Descending ||
( isRunningXPOrLater && (e.Column != groupColumn) ) )
{
myListView.Sorting = SortOrder.Ascending;
}
else
{
myListView.Sorting = SortOrder.Descending;
}
groupColumn = e.Column;
// Set the groups to those created for the clicked column.
if (isRunningXPOrLater)
{
SetGroups(e.Column);
}
}
// Sets myListView to the groups created for the specified column.
private void SetGroups(int column)
{
// Remove the current groups.
myListView.Groups.Clear();
// Retrieve the hash table corresponding to the column.
Hashtable groups = (Hashtable)groupTables[column];
// Copy the groups for the column to an array.
ListViewGroup[] groupsArray = new ListViewGroup[groups.Count];
groups.Values.CopyTo(groupsArray, 0);
// Sort the groups and add them to myListView.
Array.Sort(groupsArray, new ListViewGroupSorter(myListView.Sorting));
myListView.Groups.AddRange(groupsArray);
// Iterate through the items in myListView, assigning each
// one to the appropriate group.
foreach (ListViewItem item in myListView.Items)
{
// Retrieve the subitem text corresponding to the column.
string subItemText = item.SubItems[column].Text;
// For the Title column, use only the first letter.
if (column == 0)
{
subItemText = subItemText.Substring(0, 1);
}
// Assign the item to the matching group.
item.Group = (ListViewGroup)groups[subItemText];
}
}
// Creates a Hashtable object with one entry for each unique
// subitem value (or initial letter for the parent item)
// in the specified column.
private Hashtable CreateGroupsTable(int column)
{
// Create a Hashtable object.
Hashtable groups = new Hashtable();
// Iterate through the items in myListView.
foreach (ListViewItem item in myListView.Items)
{
// Retrieve the text value for the column.
string subItemText = item.SubItems[column].Text;
// Use the initial letter instead if it is the first column.
if (column == 0)
{
subItemText = subItemText.Substring(0, 1);
}
// If the groups table does not already contain a group
// for the subItemText value, add a new group using the
// subItemText value for the group header and Hashtable key.
if (!groups.Contains(subItemText))
{
groups.Add( subItemText, new ListViewGroup(subItemText,
HorizontalAlignment.Left) );
}
}
// Return the Hashtable object.
return groups;
}
// Sorts ListViewGroup objects by header value.
private class ListViewGroupSorter : IComparer
{
private SortOrder order;
// Stores the sort order.
public ListViewGroupSorter(SortOrder theOrder)
{
order = theOrder;
}
// Compares the groups by header value, using the saved sort
// order to return the correct value.
public int Compare(object x, object y)
{
int result = String.Compare(
((ListViewGroup)x).Header,
((ListViewGroup)y).Header
);
if (order == SortOrder.Ascending)
{
return result;
}
else
{
return -result;
}
}
}
}
Imports System.Collections
Imports System.Windows.Forms
Public Class ListViewGroupsExample
Inherits Form
Private myListView As ListView
' Determine whether Windows XP or a later
' operating system is present.
Private isRunningXPOrLater As Boolean = _
OSFeature.Feature.IsPresent(OSFeature.Themes)
' Declare a Hashtable array in which to store the groups.
Private groupTables() As Hashtable
' Declare a variable to store the current grouping column.
Private groupColumn As Integer = 0
Public Sub New()
' Initialize myListView.
myListView = New ListView()
myListView.Dock = DockStyle.Fill
myListView.View = View.Details
myListView.Sorting = SortOrder.Ascending
' Create and initialize column headers for myListView.
Dim columnHeader0 As New ColumnHeader()
columnHeader0.Text = "Title"
columnHeader0.Width = -1
Dim columnHeader1 As New ColumnHeader()
columnHeader1.Text = "Author"
columnHeader1.Width = -1
Dim columnHeader2 As New ColumnHeader()
columnHeader2.Text = "Year"
columnHeader2.Width = -1
' Add the column headers to myListView.
myListView.Columns.AddRange( New ColumnHeader() _
{columnHeader0, columnHeader1, columnHeader2} )
' Add a handler for the ColumnClick event.
AddHandler myListView.ColumnClick, AddressOf myListView_ColumnClick
' Create items and add them to myListView.
Dim item0 As New ListViewItem( New String() _
{"Programming Windows", _
"Petzold, Charles", _
"1998"} )
Dim item1 As New ListViewItem( New String() _
{"Code: The Hidden Language of Computer Hardware and Software", _
"Petzold, Charles", _
"2000"} )
Dim item2 As New ListViewItem( New String() _
{"Programming Windows with C#", _
"Petzold, Charles", _
"2001"} )
Dim item3 As New ListViewItem( New String() _
{"Coding Techniques for Microsoft Visual Basic .NET", _
"Connell, John", _
"2001"} )
Dim item4 As New ListViewItem( New String() _
{"C# for Java Developers", _
"Jones, Allen / Freeman, Adam", _
"2002"} )
Dim item5 As New ListViewItem( New String() _
{"Microsoft .NET XML Web Services Step by Step", _
"Jones, Allen / Freeman, Adam", _
"2002"} )
myListView.Items.AddRange( _
New ListViewItem() {item0, item1, item2, item3, item4, item5})
If isRunningXPOrLater
' Create the groupsTable array and populate it with one
' hash table for each column.
groupTables = New Hashtable(myListView.Columns.Count) {}
Dim column As Integer
For column = 0 To myListView.Columns.Count - 1
' Create a hash table containing all the groups
' needed for a single column.
groupTables(column) = CreateGroupsTable(column)
Next column
' Start with the groups created for the Title column.
SetGroups(0)
End If
' Initialize the form.
Me.Controls.Add(myListView)
Me.Size = New System.Drawing.Size(550, 330)
Me.Text = "ListView Groups Example"
End Sub
<STAThread()> _
Shared Sub Main()
Application.EnableVisualStyles()
Application.Run(New ListViewGroupsExample())
End Sub
' Groups the items using the groups created for the clicked
' column.
Private Sub myListView_ColumnClick( _
sender As Object, e As ColumnClickEventArgs)
' Set the sort order to ascending when changing
' column groups; otherwise, reverse the sort order.
If myListView.Sorting = SortOrder.Descending OrElse _
isRunningXPOrLater And e.Column <> groupColumn Then
myListView.Sorting = SortOrder.Ascending
Else
myListView.Sorting = SortOrder.Descending
End If
groupColumn = e.Column
' Set the groups to those created for the clicked column.
If isRunningXPOrLater Then
SetGroups(e.Column)
End If
End Sub
' Sets myListView to the groups created for the specified column.
Private Sub SetGroups(column As Integer)
' Remove the current groups.
myListView.Groups.Clear()
' Retrieve the hash table corresponding to the column.
Dim groups As Hashtable = CType(groupTables(column), Hashtable)
' Copy the groups for the column to an array.
Dim groupsArray(groups.Count - 1) As ListViewGroup
groups.Values.CopyTo(groupsArray, 0)
' Sort the groups and add them to myListView.
Array.Sort(groupsArray, New ListViewGroupSorter(myListView.Sorting))
myListView.Groups.AddRange(groupsArray)
' Iterate through the items in myListView, assigning each
' one to the appropriate group.
Dim item As ListViewItem
For Each item In myListView.Items
' Retrieve the subitem text corresponding to the column.
Dim subItemText As String = item.SubItems(column).Text
' For the Title column, use only the first letter.
If column = 0 Then
subItemText = subItemText.Substring(0, 1)
End If
' Assign the item to the matching group.
item.Group = CType(groups(subItemText), ListViewGroup)
Next item
End Sub
' Creates a Hashtable object with one entry for each unique
' subitem value (or initial letter for the parent item)
' in the specified column.
Private Function CreateGroupsTable(column As Integer) As Hashtable
' Create a Hashtable object.
Dim groups As New Hashtable()
' Iterate through the items in myListView.
Dim item As ListViewItem
For Each item In myListView.Items
' Retrieve the text value for the column.
Dim subItemText As String = item.SubItems(column).Text
' Use the initial letter instead if it is the first column.
If column = 0 Then
subItemText = subItemText.Substring(0, 1)
End If
' If the groups table does not already contain a group
' for the subItemText value, add a new group using the
' subItemText value for the group header and Hashtable key.
If Not groups.Contains(subItemText) Then
groups.Add( subItemText, New ListViewGroup(subItemText, _
HorizontalAlignment.Left) )
End If
Next item
' Return the Hashtable object.
Return groups
End Function 'CreateGroupsTable
' Sorts ListViewGroup objects by header value.
Private Class ListViewGroupSorter
Implements IComparer
Private order As SortOrder
' Stores the sort order.
Public Sub New(theOrder As SortOrder)
order = theOrder
End Sub
' Compares the groups by header value, using the saved sort
' order to return the correct value.
Public Function Compare(x As Object, y As Object) As Integer _
Implements IComparer.Compare
Dim result As Integer = String.Compare( _
CType(x, ListViewGroup).Header, _
CType(y, ListViewGroup).Header )
If order = SortOrder.Ascending Then
Return result
Else
Return -result
End If
End Function 'Compare
End Class
End Class
Remarks
The ListView grouping feature lets you create visual groups of logically related ListView items. Each group consists of a text-based header followed by a horizontal line and the items assigned to that group. You can align the header text to the left, right, or center of the control. Any groups assigned to a ListView control appear whenever the ListView.View property is set to a value other than View.List.
ListView groups help your users find the items they are looking for by separating the items into useful categories. You can create whatever categories you need. One typical way to group the items is by the way they are sorted. For example, you can group the items by the initial letter of the item name when they are sorted alphabetically, or by subitems such as type or date when the list is sorted by clicking a column header in the details view. Windows Explorer uses this type of grouping.
To use the grouping feature, add one or more ListViewGroup objects to the ListView.Groups collection of a ListView control. Set the group header text and header alignment in the ListViewGroup constructor, or set them using the Header and HeaderAlignment properties.
You can assign an item to a group by specifying the group in the ListViewItem constructor, by setting the ListViewItem.Group property, or by directly adding the item to the Items collection of a group. All items should be assigned to groups before they are displayed. Any items that are not assigned to a group will appear in the default group, which has the header label "DefaultGroup{0}". The default group is not contained in the ListView.Groups collection, and cannot be altered. It is primarily useful in debugging to ensure that all items have been properly added to groups.
An item can only be in one group at a time. You can change the group to which an item belongs by setting the ListViewItem.Group property at run time or by adding it to the Items collection of another group, which automatically removes it from the previous group.
Note
The insertion mark feature is disabled when using groups. This is because the grouping feature orders items by group membership, while the insertion mark feature is used with drag-and-drop repositioning in a ListView control that does not already order its items.
Note
ListView groups are available only on Windows XP and the Windows Server 2003 family when your application calls the Application.EnableVisualStyles method. On earlier operating systems, any code relating to groups will be ignored and the groups will not appear. As a result, any code that depends on the grouping feature might not work correctly. You might want to include a test that determines whether the grouping feature is available, and provide alternate functionality when it is unavailable. For example, you might want to provide alternate sorting when running on operating systems that do not support sorting by group.
The insertion mark feature is provided by the same library that provides the operating system themes feature. To check for the availability of this library, call the FeatureSupport.IsPresent(Object) method overload and pass in the OSFeature.Themes value.
Constructors
| ListViewGroup() |
Initializes a new instance of the ListViewGroup class using the default header text of "ListViewGroup" and the default left header alignment. |
| ListViewGroup(String, HorizontalAlignment) |
Initializes a new instance of the ListViewGroup class using the specified header text and the specified header alignment. |
| ListViewGroup(String, String) |
Initializes a new instance of the ListViewGroup class using the specified values to initialize the Name and Header properties. |
| ListViewGroup(String) |
Initializes a new instance of the ListViewGroup class using the specified value to initialize the Header property and using the default left header alignment. |
Properties
| CollapsedState |
Controls which ListViewGroupCollapsedState the group will appear as. |
| Footer |
The text displayed in the group footer. |
| FooterAlignment |
The alignment of the group footer. |
| Header |
Gets or sets the header text for the group. |
| HeaderAlignment |
Gets or sets the alignment of the group header text. |
| Items |
Gets a collection containing all items associated with this group. |
| ListView |
Gets the ListView control that contains this group. |
| Name |
Gets or sets the name of the group. |
| Subtitle |
The text displayed in the group subtitle. |
| Tag |
Gets or sets the object that contains data about the group. |
| TaskLink |
The name of the task link displayed in the group header. |
| TitleImageIndex |
Gets or sets the index of the image that is displayed for the group. |
| TitleImageKey |
Gets or sets the key of the image that is displayed for the group. |
Methods
| Equals(Object) |
Determines whether the specified object is equal to the current object. (Inherited from Object) |
| GetHashCode() |
Serves as the default hash function. (Inherited from Object) |
| GetType() |
Gets the Type of the current instance. (Inherited from Object) |
| MemberwiseClone() |
Creates a shallow copy of the current Object. (Inherited from Object) |
| ToString() |
Returns a string that represents the current object. |
Explicit Interface Implementations
| ISerializable.GetObjectData(SerializationInfo, StreamingContext) |
Populates a SerializationInfo with the data needed to serialize the target object. |
