Form.HelpButton-Eigenschaft

Ruft einen Wert ab, der angibt, ob auf der Titelleiste des Formulars die Hilfeschaltfläche angezeigt werden soll, oder legt diesen fest.

Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in system.windows.forms.dll)

Syntax

'Declaration
Public Property HelpButton As Boolean
'Usage
Dim instance As Form
Dim value As Boolean

value = instance.HelpButton

instance.HelpButton = value

public bool HelpButton { get; set; }

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

/** @property */
public boolean get_HelpButton ()

/** @property */
public void set_HelpButton (boolean value)

public function get HelpButton () : boolean

public function set HelpButton (value : boolean)

Eigenschaftenwert

true, um die Hilfeschaltfläche auf der Titelleiste des Formulars anzuzeigen, andernfalls false. Der Standardwert ist false.

Hinweise

Wenn diese Eigenschaft auf true festgelegt ist, wird auf der Titelleiste links neben der Schaltfläche Schließen eine kleine Schaltfläche mit einem Fragezeichen angezeigt. Mithilfe dieser Schaltfläche kann die Hilfe für die Anwendung angezeigt werden. Sie können einen Ereignishandler für das HelpRequested-Ereignis der Control-Klasse erstellen, um Hilfeinformationen anzuzeigen, wenn der Benutzer auf die Hilfeschaltfläche des Formulars klickt.

Wenn die Schaltflächen Maximieren oder Minimieren angezeigt werden, wird der Wert der HelpButton-Eigenschaft ignoriert.

Beispiel

Im folgenden Codebeispiel wird eine neue Instanz von Form erstellt. Anschließend wird die ShowDialog-Methode aufgerufen, um das Formular als Dialogfeld anzuzeigen. Im Beispiel werden die Eigenschaften FormBorderStyle, AcceptButton, CancelButton, MinimizeBox, MaximizeBox und StartPosition geändert, um dem Formular die Darstellung und Funktionsweise eines Dialogfelds zu verleihen. Im Beispiel wird zudem die Add-Methode der Controls-Auflistung des Formulars verwendet, um zwei Button-Steuerelemente hinzuzufügen. Im Beispiel wird mit der HelpButton-Eigenschaft eine Hilfeschaltfläche auf der Titelleiste des Dialogfelds angezeigt.

Public Sub CreateMyForm()
    ' Create a new instance of the form.
    Dim form1 As New Form()
    ' Create two buttons to use as the accept and cancel buttons.
    Dim button1 As New Button()
    Dim button2 As New Button()
       
    ' Set the text of button1 to "OK".
    button1.Text = "OK"
    ' Set the position of the button on the form.
    button1.Location = New Point(10, 10)
    ' Set the text of button2 to "Cancel".
    button2.Text = "Cancel"
    ' Set the position of the button based on the location of button1.
    button2.Location = _
       New Point(button1.Left, button1.Height + button1.Top + 10)
    ' Set the caption bar text of the form.   
    form1.Text = "My Dialog Box"
    ' Display a help button on the form.
    form1.HelpButton = True
       
    ' Define the border style of the form to a dialog box.
    form1.FormBorderStyle = FormBorderStyle.FixedDialog
    ' Set the MaximizeBox to false to remove the maximize box.
    form1.MaximizeBox = False
    ' Set the MinimizeBox to false to remove the minimize box.
    form1.MinimizeBox = False
    ' Set the accept button of the form to button1.
    form1.AcceptButton = button1
    ' Set the cancel button of the form to button2.
    form1.CancelButton = button2
    ' Set the start position of the form to the center of the screen.
    form1.StartPosition = FormStartPosition.CenterScreen
       
    ' Add button1 to the form.
    form1.Controls.Add(button1)
    ' Add button2 to the form.
    form1.Controls.Add(button2)
       
    ' Display the form as a modal dialog box.
    form1.ShowDialog()
End Sub

public void CreateMyForm()
{
   // Create a new instance of the form.
   Form form1 = new Form();
   // Create two buttons to use as the accept and cancel buttons.
   Button button1 = new Button ();
   Button button2 = new Button ();
  
   // Set the text of button1 to "OK".
   button1.Text = "OK";
   // Set the position of the button on the form.
   button1.Location = new Point (10, 10);
   // Set the text of button2 to "Cancel".
   button2.Text = "Cancel";
   // Set the position of the button based on the location of button1.
   button2.Location
      = new Point (button1.Left, button1.Height + button1.Top + 10);
   // Set the caption bar text of the form.   
   form1.Text = "My Dialog Box";
   // Display a help button on the form.
   form1.HelpButton = true;

   // Define the border style of the form to a dialog box.
   form1.FormBorderStyle = FormBorderStyle.FixedDialog;
   // Set the MaximizeBox to false to remove the maximize box.
   form1.MaximizeBox = false;
   // Set the MinimizeBox to false to remove the minimize box.
   form1.MinimizeBox = false;
   // Set the accept button of the form to button1.
   form1.AcceptButton = button1;
   // Set the cancel button of the form to button2.
   form1.CancelButton = button2;
   // Set the start position of the form to the center of the screen.
   form1.StartPosition = FormStartPosition.CenterScreen;
   
   // Add button1 to the form.
   form1.Controls.Add(button1);
   // Add button2 to the form.
   form1.Controls.Add(button2);
   
   // Display the form as a modal dialog box.
   form1.ShowDialog();
}

public:
   void CreateMyForm()
   {
      // Create a new instance of the form.
      Form^ form1 = gcnew Form;
      // Create two buttons to use as the accept and cancel buttons.
      Button^ button1 = gcnew Button;
      Button^ button2 = gcnew Button;
      
      // Set the text of button1 to "OK".
      button1->Text = "OK";
      // Set the position of the button on the form.
      button1->Location = Point(10,10);
      // Set the text of button2 to "Cancel".
      button2->Text = "Cancel";
      // Set the position of the button based on the location of button1.
      button2->Location =
         Point( button1->Left, button1->Height + button1->Top + 10 );
      // Set the caption bar text of the form.   
      form1->Text = "My Dialog Box";
      // Display a help button on the form.
      form1->HelpButton = true;
      
      // Define the border style of the form to a dialog box.
      form1->FormBorderStyle = ::FormBorderStyle::FixedDialog;
      // Set the MaximizeBox to false to remove the maximize box.
      form1->MaximizeBox = false;      
      // Set the MinimizeBox to false to remove the minimize box.
      form1->MinimizeBox = false;
      // Set the accept button of the form to button1.
      form1->AcceptButton = button1;
      // Set the cancel button of the form to button2.
      form1->CancelButton = button2;
      // Set the start position of the form to the center of the screen.
      form1->StartPosition = FormStartPosition::CenterScreen;
      
      // Add button1 to the form.
      form1->Controls->Add( button1 );
      // Add button2 to the form.
      form1->Controls->Add( button2 );
      // Display the form as a modal dialog box.
      form1->ShowDialog();
   }

public void CreateMyForm()
{
    // Create a new instance of the form.
    Form form1 = new Form();

    // Create two buttons to use as the accept and cancel buttons.
    Button button1 = new Button();
    Button button2 = new Button();

    // Set the text of button1 to "OK".
    button1.set_Text("OK");

    // Set the position of the button on the form.
    button1.set_Location(new Point(10, 10));

    // Set the text of button2 to "Cancel".
    button2.set_Text("Cancel");

    // Set the position of the button based on the location of button1.
    button2.set_Location(new Point(button1.get_Left(), 
        button1.get_Height() + button1.get_Top() + 10));

    // Set the caption bar text of the form.   
    form1.set_Text("My Dialog Box");

    // Display a help button on the form.
    form1.set_HelpButton(true);

    // Define the border style of the form to a dialog box.
    form1.set_FormBorderStyle(get_FormBorderStyle().FixedDialog);

    // Set the MaximizeBox to false to remove the maximize box.
    form1.set_MaximizeBox(false);

    // Set the MinimizeBox to false to remove the minimize box.
    form1.set_MinimizeBox(false);

    // Set the accept button of the form to button1.
    form1.set_AcceptButton(button1);

    // Set the cancel button of the form to button2.
    form1.set_CancelButton(button2);

    // Set the start position of the form to the center of the screen.
    form1.set_StartPosition(FormStartPosition.CenterScreen);

    // Add button1 to the form.
    form1.get_Controls().Add(button1);

    // Add button2 to the form.
    form1.get_Controls().Add(button2);

    // Display the form as a modal dialog box.
    form1.ShowDialog();
} //CreateMyForm

Plattformen

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile für Pocket PC, Windows Mobile für Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.

Versionsinformationen

.NET Framework

Unterstützt in: 2.0, 1.1, 1.0

Siehe auch

Referenz

Form-Klasse
Form-Member
System.Windows.Forms-Namespace
MinimizeBox
MaximizeBox
Form.ControlBox-Eigenschaft
HelpButtonClicked