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CommonDialog.HelpRequest 事件

定義

發生於使用者按一下通用對話方塊上的 [說明] 按鈕時。

public:
 event EventHandler ^ HelpRequest;
public event EventHandler HelpRequest;
public event EventHandler? HelpRequest;
member this.HelpRequest : EventHandler 
Public Custom Event HelpRequest As EventHandler 

事件類型

範例

下列程式碼範例示範初始化 ColorDialog 物件設定 AnyColorAllowFullOpen 屬性。 物件 ColorDialog 不允許使用者設定自訂色彩,但允許顯示一組完整的基本色彩。 藉由將 SolidColorOnly 屬性設定為 false,它允許在具有 256 個或更少色彩的系統上顯示其他色彩組合的色彩。 此範例也會示範如何設定 ShowHelp 屬性和處理 HelpRequest 對話方塊的事件。 若要執行此範例,請將下列程式碼貼到表單中,並在表單的建構函式或 Load 方法中呼叫 InitializeColorDialog 方法。 這個範例會要求 Click 按鈕的 事件連接到範例中定義的事件處理常式。

// This method initializes ColorDialog1 to allow any colors, 
// and combination colors on systems with 256 colors or less, 
// but will not allow the user to set custom colors.  The
// dialog will contain the help button.
void InitializeColorDialog()
{
   this->ColorDialog1 = gcnew System::Windows::Forms::ColorDialog;
   this->ColorDialog1->AllowFullOpen = false;
   this->ColorDialog1->AnyColor = true;
   this->ColorDialog1->SolidColorOnly = false;
   this->ColorDialog1->ShowHelp = true;
   
   // Associate the event-handling method with
   // the HelpRequest event.
   this->ColorDialog1->HelpRequest +=
      gcnew System::EventHandler( this, &Form1::ColorDialog1_HelpRequest );
}

// This method opens the dialog and checks the DialogResult value. 
// If the result is OK, the text box's background color will be changed 
// to the user-selected color.
void Button1_Click( System::Object^ sender, System::EventArgs^ e )
{
   ::DialogResult result = ColorDialog1->ShowDialog();
   if ( result == ::DialogResult::OK )
   {
      TextBox1->BackColor = ColorDialog1->Color;
   }
}

// This method is called when the HelpRequest event is raised, 
//which occurs when the user clicks the Help button on the ColorDialog object.
void ColorDialog1_HelpRequest( Object^ sender, System::EventArgs^ e )
{
   MessageBox::Show( "Please select a color by clicking it. " +
      "This will change the BackColor property of the TextBox." );
}
// This method initializes ColorDialog1 to allow any colors, 
// and combination colors on systems with 256 colors or less, 
// but will not allow the user to set custom colors.  The
// dialog will contain the help button.
private void InitializeColorDialog()
{
    this.ColorDialog1 = new System.Windows.Forms.ColorDialog();
    this.ColorDialog1.AllowFullOpen = false;
    this.ColorDialog1.AnyColor = true;
    this.ColorDialog1.SolidColorOnly = false;
    this.ColorDialog1.ShowHelp = true;
    
    // Associate the event-handling method with
    // the HelpRequest event.
    this.ColorDialog1.HelpRequest 
        += new System.EventHandler(ColorDialog1_HelpRequest);
}

// This method opens the dialog and checks the DialogResult value. 
// If the result is OK, the text box's background color will be changed 
// to the user-selected color.
private void Button1_Click(System.Object sender, System.EventArgs e)
{
    DialogResult result = ColorDialog1.ShowDialog();
    if (result.Equals(DialogResult.OK))
    {
        TextBox1.BackColor = ColorDialog1.Color;
    }
}

// This method is called when the HelpRequest event is raised, 
//which occurs when the user clicks the Help button on the ColorDialog object.
private void ColorDialog1_HelpRequest(object sender, System.EventArgs e)
{

    MessageBox.Show("Please select a color by clicking it. "
       + "This will change the BackColor property of the TextBox.");
}
   
   ' This method initializes ColorDialog1 to allow any colors, 
   ' and combination colors on systems with 256 colors or less, 
   ' but will not allow the user to set custom colors.  The
   ' dialog will contain the help button.
   Private Sub InitializeColorDialog()
       Me.ColorDialog1 = New System.Windows.Forms.ColorDialog
       Me.ColorDialog1.AllowFullOpen = False
       Me.ColorDialog1.AnyColor = True
       Me.ColorDialog1.SolidColorOnly = False
       Me.ColorDialog1.ShowHelp = True
   End Sub
 

   ' This method opens the dialog and checks the DialogResult value. 
   ' If the result is OK, the text box's background color will be changed 
   ' to the user-selected color.
   Private Sub Button1_Click(ByVal sender As System.Object,  _
       ByVal e As System.EventArgs) Handles Button1.Click
       Dim result As DialogResult = ColorDialog1.ShowDialog()
       If (result.Equals(DialogResult.OK)) Then
           TextBox1.BackColor = ColorDialog1.Color
       End If
   End Sub

 
   ' This method is called when the HelpRequest event is raised, 
   'which occurs when the user clicks the Help button on the ColorDialog object.
   Private Sub ColorDialog1_HelpRequest(ByVal sender As Object, _ 
       ByVal e As System.EventArgs) Handles ColorDialog1.HelpRequest

       MessageBox.Show("Please select a color by clicking it." _
       & "This will change the BackColor property of the TextBox.")
   End Sub

備註

如需處理事件的資訊,請參閱 處理和引發事件

適用於

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