ListView::ListViewItemSorter Property

 
System_CAPS_noteNote

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Gets or sets the sorting comparer for the control.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

public:
[BrowsableAttribute(false)]
property IComparer^ ListViewItemSorter {
	IComparer^ get();
	void set(IComparer^ value);
}

Property Value

Type: System.Collections::IComparer^

An IComparer that represents the sorting comparer for the control.

The ListViewItemSorter property allows you to specify the object that performs the sorting of items in a ListView control when the Sort method is called or when items are added to the list. Note that items are not sorted automatically when their label text changes.

The specified object must be an instance of a class that implements the IComparer interface, which has a single method called Comparer::Compare.

You can use this property to provide custom sorting, for example, when a column header is clicked in the details view. To do this, create a class that implements the IComparer interface and provides a constructor that accepts the index of a column to sort by. You can then implement a handler for the ColumnClick event that creates an instance of this class using the index of the clicked column. When you set the ListViewItemSorter property to the new instance, the ListView control is automatically sorted using the specified object. Subsequent calls to the Sort method use the same object.

System_CAPS_noteNote

When you set the value of the ListViewItemSorter property, the Sort method is called automatically.

The following code example creates a form that contains a ListView control that manually sorts items when a column in the ListView control is clicked. The example defines a class called ListViewItemComparer that implements the System.Collections::IComparer interface that performs the ListViewItem comparison. The example creates an instance of ListViewItemComparer and uses it to set the ListViewItemSorter property of the ListView control. The Sort method call in the ColumnClick event handler uses the methods defined in ListViewItemComparer to perform the sort of items, based on the column that is clicked.

#using <System.dll>
#using <System.Drawing.dll>
#using <System.Windows.Forms.dll>

using namespace System;
using namespace System::Windows::Forms;
using namespace System::Drawing;
using namespace System::Collections;

// Implements the manual sorting of items by columns.
ref class ListViewItemComparer: public IComparer
{
private:
   int col;

public:
   ListViewItemComparer()
   {
      col = 0;
   }

   ListViewItemComparer( int column )
   {
      col = column;
   }

   virtual int Compare( Object^ x, Object^ y )
   {
      return String::Compare( (dynamic_cast<ListViewItem^>(x))->SubItems[ col ]->Text,
                              (dynamic_cast<ListViewItem^>(y))->SubItems[ col ]->Text );
   }
};

public ref class ListViewSortForm: public Form
{
private:
   ListView^ listView1;

public:
   ListViewSortForm()
   {
      // Create ListView items to add to the control.
      array<String^>^temp0 = {"Banana","a","b","c"};
      ListViewItem^ listViewItem1 = gcnew ListViewItem( temp0,-1,Color::Empty,Color::Yellow,nullptr );
      array<String^>^temp1 = {"Cherry","v","g","t"};
      ListViewItem^ listViewItem2 = gcnew ListViewItem( temp1,-1,Color::Empty,Color::Red,
                 gcnew System::Drawing::Font( "Microsoft Sans Serif",8.25F,FontStyle::Regular,GraphicsUnit::Point,0 ) );
      array<String^>^temp2 = {"Apple","h","j","n"};
      ListViewItem^ listViewItem3 = gcnew ListViewItem( temp2,-1,Color::Empty,Color::Lime,nullptr );
      array<String^>^temp3 = {"Pear","y","u","i"};
      ListViewItem^ listViewItem4 = gcnew ListViewItem( temp3,-1,Color::Empty,Color::FromArgb( 192, 128, 156 ),nullptr );

      //Initialize the ListView control and add columns to it.
      this->listView1 = gcnew ListView;

      // Set the initial sorting type for the ListView.
      this->listView1->Sorting = SortOrder::None;

      // Disable automatic sorting to enable manual sorting.
      this->listView1->View = View::Details;

      // Add columns and set their text.
      this->listView1->Columns->Add( gcnew ColumnHeader );
      this->listView1->Columns[ 0 ]->Text = "Column 1";
      this->listView1->Columns[ 0 ]->Width = 100;
      listView1->Columns->Add( gcnew ColumnHeader );
      listView1->Columns[ 1 ]->Text = "Column 2";
      listView1->Columns->Add( gcnew ColumnHeader );
      listView1->Columns[ 2 ]->Text = "Column 3";
      listView1->Columns->Add( gcnew ColumnHeader );
      listView1->Columns[ 3 ]->Text = "Column 4";

      // Suspend control logic until form is done configuring form.
      this->SuspendLayout();

      // Add Items to the ListView control.
      array<ListViewItem^>^temp4 = {listViewItem1,listViewItem2,listViewItem3,listViewItem4};
      this->listView1->Items->AddRange( temp4 );

      // Set the location and size of the ListView control.
      this->listView1->Location = Point(10,10);
      this->listView1->Name = "listView1";
      this->listView1->Size = System::Drawing::Size( 300, 100 );
      this->listView1->TabIndex = 0;

      // Enable editing of the items in the ListView.
      this->listView1->LabelEdit = true;

      // Connect the ListView::ColumnClick event to the ColumnClick event handler.
      this->listView1->ColumnClick += gcnew ColumnClickEventHandler( this, &ListViewSortForm::ColumnClick );

      // Initialize the form.
      this->ClientSize = System::Drawing::Size( 400, 400 );
      array<Control^>^temp5 = {this->listView1};
      this->Controls->AddRange( temp5 );
      this->Name = "ListViewSortForm";
      this->Text = "Sorted ListView Control";

      // Resume lay[Out] of* the form.
      this->ResumeLayout( false );
   }

private:

   // ColumnClick event handler.
   void ColumnClick( Object^ /*o*/, ColumnClickEventArgs^ e )
   {
      // Set the ListViewItemSorter property to a new ListViewItemComparer 
      // object. Setting this property immediately sorts the 
      // ListView using the ListViewItemComparer object.
      this->listView1->ListViewItemSorter = gcnew ListViewItemComparer( e->Column );
   }
};

[System::STAThreadAttribute]
int main()
{
   Application::Run( gcnew ListViewSortForm );
}

.NET Framework
Available since 1.1
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