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ListBox::ScrollAlwaysVisible Property

Gets or sets a value indicating whether the vertical scroll bar is shown at all times.

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

public:
property bool ScrollAlwaysVisible {
	bool get ();
	void set (bool value);
}

Property Value

Type: System::Boolean
true if the vertical scroll bar should always be displayed; otherwise, false. The default is false.

The ScrollAlwaysVisible property indicates whether a vertical scroll bar is always displayed, even if the number of items in the ListBox does not require displaying the vertical scroll bar. By default, a ListBox only shows a vertical scroll bar when there are enough items to warrant displaying. For a multicolumn ListBox, the ScrollAlwaysVisible property indicates that a horizontal scroll bar is displayed. A vertical scroll bar is never displayed regardless of the value of this property for a multicolumn ListBox.

The following code example demonstrates an owner-drawn ListBox by setting the DrawMode property to the OwnerDrawVariable value and handling the DrawItem and MeasureItem events. It also demonstrates setting the BorderStyle and ScrollAlwaysVisible properties and using the AddRange method.

To run this example, paste it in an empty form that imports the System.Drawing namespace and the System.Windows.Forms namespace. Call InitializeOwnerDrawnListBox from the form's constructor or Load event-handling method.

internal:
   System::Windows::Forms::ListBox^ ListBox1;

private:
   void InitializeOwnerDrawnListBox()
   {
      this->ListBox1 = gcnew System::Windows::Forms::ListBox;

      // Set the location and size.
      ListBox1->Location = Point(20,20);
      ListBox1->Size = System::Drawing::Size( 240, 240 );

      // Populate the ListBox.ObjectCollection property  
      // with several strings, using the AddRange method. 
      array<Object^>^temp0 = {"System.Windows.Forms","System.Drawing","System.Xml","System.Net","System.Runtime.Remoting","System.Web"};
      this->ListBox1->Items->AddRange( temp0 );

      // Turn off the scrollbar.
      ListBox1->ScrollAlwaysVisible = false;

      // Set the border style to a single, flat border.
      ListBox1->BorderStyle = BorderStyle::FixedSingle;

      // Set the DrawMode property to the OwnerDrawVariable value.  
      // This means the MeasureItem and DrawItem events must be  
      // handled.
      ListBox1->DrawMode = DrawMode::OwnerDrawVariable;
      ListBox1->MeasureItem += gcnew MeasureItemEventHandler( this, &Form1::ListBox1_MeasureItem );
      ListBox1->DrawItem += gcnew DrawItemEventHandler( this, &Form1::ListBox1_DrawItem );
      this->Controls->Add( this->ListBox1 );
   }

   // Handle the DrawItem event for an owner-drawn ListBox. 
   void ListBox1_DrawItem( Object^ /*sender*/, DrawItemEventArgs^ e )
   {
      // If the item is the selected item, then draw the rectangle 
      // filled in blue. The item is selected when a bitwise And   
      // of the State property and the DrawItemState.Selected  
      // property is true. 
      if ( (e->State & DrawItemState::Selected) == DrawItemState::Selected )
      {
         e->Graphics->FillRectangle( Brushes::CornflowerBlue, e->Bounds );
      }
      else
      {

         // Otherwise, draw the rectangle filled in beige.
         e->Graphics->FillRectangle( Brushes::Beige, e->Bounds );
      }

      // Draw a rectangle in blue around each item.
      e->Graphics->DrawRectangle( Pens::Blue, e->Bounds );

      // Draw the text in the item.
      e->Graphics->DrawString( ListBox1->Items[ e->Index ]->ToString(), this->Font, Brushes::Black, (float)e->Bounds.X, (float)e->Bounds.Y );

      // Draw the focus rectangle around the selected item.
      e->DrawFocusRectangle();
   }


   // Handle the MeasureItem event for an owner-drawn ListBox. 
   void ListBox1_MeasureItem( Object^ sender, MeasureItemEventArgs^ e )
   {

      // Cast the sender object back to ListBox type.
      ListBox^ theListBox = dynamic_cast<ListBox^>(sender);

      // Get the string contained in each item.
      String^ itemString = dynamic_cast<String^>(theListBox->Items[ e->Index ]);

      // Split the string at the " . "  character.
      array<Char>^temp1 = {'.'};
      array<String^>^resultStrings = itemString->Split( temp1 );

      // If the string contains more than one period, increase the  
      // height by ten pixels; otherwise, increase the height by  
      // five pixels. 
      if ( resultStrings->Length > 2 )
      {
         e->ItemHeight += 10;
      }
      else
      {
         e->ItemHeight += 5;
      }
   }
	an owner-drawn ListBox by setting the the DrawMode property to OwnerDrawVariable value and
	handling the DrawItem and MeasureItem events.  It also demonstrates setting the 
	BorderStyle and ScrollAlwaysVisible properties and using the AddRange method.

	To run this example paste it in an empty form that imports the System.Drawing
	namespace and the System.Windows.Forms namespace.

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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