ListView.Groups Properti
Definisi
Penting
Beberapa informasi terkait produk prarilis yang dapat diubah secara signifikan sebelum dirilis. Microsoft tidak memberikan jaminan, tersirat maupun tersurat, sehubungan dengan informasi yang diberikan di sini.
Mendapatkan kumpulan ListViewGroup objek yang ditetapkan ke kontrol.
public:
property System::Windows::Forms::ListViewGroupCollection ^ Groups { System::Windows::Forms::ListViewGroupCollection ^ get(); };
public System.Windows.Forms.ListViewGroupCollection Groups { get; }
member this.Groups : System.Windows.Forms.ListViewGroupCollection
Public ReadOnly Property Groups As ListViewGroupCollection
Nilai Properti
ListViewGroupCollection yang berisi semua grup dalam ListView kontrol.
Contoh
Contoh kode berikut menunjukkan cara menggunakan ListView fitur pengelompokan untuk menata item menurut nilai subitem dalam tampilan detail. Bentuk pengelompokan ini mirip dengan pengelompokan yang digunakan di Windows Explorer. Dalam contoh, grup dibuat secara dinamis. Untuk setiap kolom subitem, satu grup dibuat untuk setiap nilai subitem unik. Untuk kolom item induk, satu grup dibuat untuk setiap huruf awal yang unik. Mengklik header kolom akan mengurutkan item ke dalam grup yang dibuat untuk kolom tersebut. Mengklik header kolom yang sama lagi akan membalikkan urutan grup.
#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
Keterangan
Fitur ListView pengelompokan memungkinkan Anda membuat grup visual item terkait ListView logis. Setiap grup terdiri dari header tekstual diikuti dengan garis horizontal dan item yang ditetapkan ke grup tersebut. Anda dapat meratakan teks header ke kiri, kanan, atau tengah kontrol. Setiap grup yang ListView ditetapkan ke kontrol muncul setiap kali View properti diatur ke nilai selain View.List.
ListView grup membantu pengguna Anda menemukan item yang mereka cari dengan memisahkan item ke dalam kategori yang berguna. Anda dapat membuat kategori apa pun yang Anda butuhkan. Salah satu pendekatan umumnya adalah mengelompokkan item berdasarkan cara daftar diurutkan. Misalnya, Anda dapat mengelompokkan item menurut huruf awal nama item saat daftar diurutkan menurut abjad atau menurut subitem seperti jenis atau tanggal saat daftar diurutkan dengan mengklik header kolom dalam tampilan detail. Windows Explorer menggunakan jenis pengelompokan ini.
Untuk menggunakan fitur pengelompokan, tambahkan satu atau beberapa ListViewGroup objek ke Groups kumpulan ListView kontrol. Atur teks header grup dan perataan header di ListViewGroup konstruktor, atau atur menggunakan ListViewGroup.Header properti dan ListViewGroup.HeaderAlignment .
Untuk menonaktifkan sementara fitur pengelompokan, atur ShowGroups properti ke false
.
Anda dapat menetapkan item ke grup dengan menentukan grup di ListViewItem konstruktor, dengan mengatur ListViewItem.Group properti , atau dengan langsung menambahkan item ke ListViewGroup.Items kumpulan grup. Semua item harus ditetapkan ke grup sebelum ditampilkan. Item apa pun yang tidak ditetapkan ke grup akan muncul di grup default, yang memiliki label header "DefaultGroup{0}". Grup default tidak terkandung dalam Groups koleksi, dan tidak dapat diubah. Ini terutama berguna dalam penelusuran kesalahan untuk memastikan bahwa semua item telah ditambahkan dengan benar ke grup.
Item hanya dapat berada dalam satu grup pada satu waktu. Anda dapat mengubah grup tempat item berada dengan mengatur properti pada ListViewItem.Group durasi atau dengan menambahkannya ke ListViewGroup.Items kumpulan grup lain, yang secara otomatis menghapusnya dari grup sebelumnya.
Fitur tanda penyisipan dinonaktifkan saat menggunakan grup. Ini karena fitur pengelompokan memesan item menurut keanggotaan grup, sementara fitur tanda penyisipan digunakan dengan reposisi seret dan letakkan dalam ListView kontrol yang belum mengurutkan itemnya.
ListViewgrup hanya tersedia di Windows XP dan Windows Server 2003 saat aplikasi Anda memanggil metode .Application.EnableVisualStyles Pada sistem operasi sebelumnya, kode apa pun yang berkaitan dengan grup tidak berpengaruh dan grup tidak akan muncul. Akibatnya, kode apa pun yang bergantung pada fitur pengelompokan mungkin tidak berfungsi dengan benar.
Anda mungkin ingin menyertakan kode yang menentukan apakah fitur pengelompokan tersedia, dan menyediakan fungsionalitas alternatif saat tidak tersedia. Misalnya, Anda mungkin ingin menyediakan pengurutan alternatif saat berjalan pada sistem operasi yang tidak mendukung pengurutan menurut grup.
Fitur pengelompokan disediakan oleh pustaka yang sama yang menyediakan fitur tema sistem operasi. Untuk memeriksa ketersediaan pustaka ini, panggil FeatureSupport.IsPresent(Object) metode kelebihan beban dan berikan nilainya OSFeature.Themes .