TreeView.Scrollable Proprietà

Definizione

Spazio dei nomi:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Ottiene o imposta un valore che indica se nel controllo di visualizzazione albero vengono visualizzate barre di scorrimento quando necessario.

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

public bool Scrollable { get; set; }

member this.Scrollable : bool with get, set

Public Property Scrollable As Boolean

Valore della proprietà

Boolean

true se nel controllo di visualizzazione ad albero vengono visualizzate le barre di scorrimento quando necessario; in caso contrario, false. Il valore predefinito è true.

Esempio

Nell'esempio di codice seguente viene illustrato come usare l'enumerazione e le BorderStyleBorderStyleproprietà , ShowLines, ScrollableHideSelection e ShowRootLines . Per eseguire questo esempio, incollare il codice seguente in un modulo e chiamare il InitializeTreeView metodo nel costruttore o Load nel metodo del modulo.

   // Declare the TreeView control.
internal:
   System::Windows::Forms::TreeView^ TreeView1;

private:
   // Initialize the TreeView to blend with the form, giving it the 
   // same color as the form and no border.
   void InitializeTreeView()
   {
      // Create a new TreeView control and set the location and size.
      this->TreeView1 = gcnew System::Windows::Forms::TreeView;
      this->TreeView1->Location = System::Drawing::Point( 72, 48 );
      this->TreeView1->Size = System::Drawing::Size( 200, 200 );

      // Set the BorderStyle property to none, the BackColor property to  
      // the form's backcolor, and the Scrollable property to false.  
      // This allows the TreeView to blend in form.
      this->TreeView1->BorderStyle = BorderStyle::None;
      this->TreeView1->BackColor = this->BackColor;
      this->TreeView1->Scrollable = false;

      // Set the HideSelection property to false to keep the 
      // selection highlighted when the user leaves the control. 
      // This helps it blend with form.
      this->TreeView1->HideSelection = false;

      // Set the ShowRootLines and ShowLines properties to false to 
      // give the TreeView a list-like appearance.
      this->TreeView1->ShowRootLines = false;
      this->TreeView1->ShowLines = false;

      // Add the nodes.
      array<TreeNode^>^temp0 = {gcnew TreeNode( "Full Color" ),gcnew TreeNode( "Project Wizards" ),gcnew TreeNode( "Visual C# and Visual Basic Support" )};
      array<TreeNode^>^temp1 = {gcnew TreeNode( "Pentium 133 MHz or faster processor " ),gcnew TreeNode( "Windows 98 or later" ),gcnew TreeNode( "100 MB Disk space" )};
      array<TreeNode^>^temp2 = {gcnew TreeNode( "Features",temp0 ),gcnew TreeNode( "System Requirements",temp1 )};
      this->TreeView1->Nodes->AddRange( temp2 );

      // Set the tab index and add the TreeView to the form.
      this->TreeView1->TabIndex = 0;
      this->Controls->Add( this->TreeView1 );
   }

// Declare the TreeView control.
internal System.Windows.Forms.TreeView TreeView1;

// Initialize the TreeView to blend with the form, giving it the 
// same color as the form and no border.
private void InitializeTreeView()
{

    // Create a new TreeView control and set the location and size.
    this.TreeView1 = new System.Windows.Forms.TreeView();
    this.TreeView1.Location = new System.Drawing.Point(72, 48);
    this.TreeView1.Size = new System.Drawing.Size(200, 200);

    // Set the BorderStyle property to none, the BackColor property to  
    // the form's backcolor, and the Scrollable property to false.  
    // This allows the TreeView to blend in form.

    this.TreeView1.BorderStyle = BorderStyle.None;
    this.TreeView1.BackColor = this.BackColor;
    this.TreeView1.Scrollable = false;

    // Set the HideSelection property to false to keep the 
    // selection highlighted when the user leaves the control. 
    // This helps it blend with form.
    this.TreeView1.HideSelection = false;

    // Set the ShowRootLines and ShowLines properties to false to 
    // give the TreeView a list-like appearance.
    this.TreeView1.ShowRootLines = false;
    this.TreeView1.ShowLines = false;

    // Add the nodes.
    this.TreeView1.Nodes.AddRange(new TreeNode[]
        {new TreeNode("Features", 
            new TreeNode[]{
            new TreeNode("Full Color"), 
            new TreeNode("Project Wizards"), 
            new TreeNode("Visual C# and Visual Basic Support")}), 
            new TreeNode("System Requirements", 
            new TreeNode[]{
                new TreeNode("Pentium 133 MHz or faster processor "),
                new TreeNode("Windows 98 or later"), 
                new TreeNode("100 MB Disk space")})
        });

    // Set the tab index and add the TreeView to the form.
    this.TreeView1.TabIndex = 0;
    this.Controls.Add(this.TreeView1);
}

' Declare the TreeView control.
Friend WithEvents TreeView1 As System.Windows.Forms.TreeView

' Initialize the TreeView to blend with the form, giving it the 
' same color as the form and no border.
Private Sub InitializeTreeView()

    ' Create a new TreeView control and set the location and size.
    Me.TreeView1 = New System.Windows.Forms.TreeView
    Me.TreeView1.Location = New System.Drawing.Point(72, 48)
    Me.TreeView1.Size = New System.Drawing.Size(200, 200)

    ' Set the BorderStyle property to none, the BackColor property to  
    ' the form's backcolor, and the Scrollable property to false.  
    ' This allows the TreeView to blend in form.
    Me.TreeView1.BorderStyle = BorderStyle.None
    Me.TreeView1.BackColor = Me.BackColor
    Me.TreeView1.Scrollable = False

    
    ' Set the ShowRootLines and ShowLines properties to false to 
    ' give the TreeView a list-like appearance.
    Me.TreeView1.ShowRootLines = False
    Me.TreeView1.ShowLines = False

    ' Add the nodes.
    Me.TreeView1.Nodes.AddRange(New System.Windows.Forms.TreeNode() _
        {New System.Windows.Forms.TreeNode("Features", _
        New System.Windows.Forms.TreeNode() _
        {New System.Windows.Forms.TreeNode("Full Color"), _
        New System.Windows.Forms.TreeNode("Project Wizards"), _
        New System.Windows.Forms.TreeNode("Visual C# and Visual Basic Support")}), _
        New System.Windows.Forms.TreeNode("System Requirements", _
        New System.Windows.Forms.TreeNode() _
        {New System.Windows.Forms.TreeNode _
        ("Pentium 133 MHz or faster processor "), _
        New System.Windows.Forms.TreeNode("Windows 98 or later"), _
        New System.Windows.Forms.TreeNode("100 MB Disk space")})})

    ' Set the tab index and add the TreeView to the form.
    Me.TreeView1.TabIndex = 0
    Me.Controls.Add(Me.TreeView1)
End Sub

Commenti

Se questa proprietà è impostata su true, le barre di scorrimento vengono visualizzate nella TreeView posizione in cui si TreeNode trovano all'esterno dell'area client del controllo.

Nota

Quando si imposta la Scrollable proprietà in fase di esecuzione, l'handle TreeView viene ricreato (vedere Control.RecreateHandle) per aggiornare l'aspetto del controllo. In questo modo tutti i nodi dell'albero devono essere compressi, ad eccezione dell'oggetto selezionato TreeNode.