HelpEventArgs Clase

Definición

Espacio de nombres:

System.Windows.Forms

Ensamblado:

System.Windows.Forms.dll

Proporciona datos para el evento HelpRequested.

public ref class HelpEventArgs : EventArgs

public class HelpEventArgs : EventArgs

type HelpEventArgs = class
    inherit EventArgs

Public Class HelpEventArgs
Inherits EventArgs

Herencia

Object

EventArgs

HelpEventArgs

Ejemplos

En el ejemplo siguiente se muestra cómo controlar el HelpRequested evento para mostrar el contenido personalizado de la Ayuda en un formulario que contiene cuatro campos de dirección. El HelpRequested evento se genera presionando la tecla F1 con el foco en un campo de dirección, o mediante el uso del botón Ayuda contextual y haciendo clic en el cursor ayuda en un campo de dirección. La Handled propiedad se establece en true para indicar que se controla el HelpRequested evento. En el ejemplo también se muestra cómo almacenar el texto de la Ayuda en la Control.Tag propiedad .

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

using namespace System;
using namespace System::Drawing;
using namespace System::Windows::Forms;
public ref class Form1: public System::Windows::Forms::Form
{
private:
   System::Windows::Forms::TextBox^ addressTextBox;
   System::Windows::Forms::Label ^ label2;
   System::Windows::Forms::TextBox^ cityTextBox;
   System::Windows::Forms::Label ^ label3;
   System::Windows::Forms::TextBox^ stateTextBox;
   System::Windows::Forms::TextBox^ zipTextBox;
   System::Windows::Forms::Label ^ helpLabel;

public:
   Form1()
   {
      this->addressTextBox = gcnew System::Windows::Forms::TextBox;
      this->helpLabel = gcnew System::Windows::Forms::Label;
      this->label2 = gcnew System::Windows::Forms::Label;
      this->cityTextBox = gcnew System::Windows::Forms::TextBox;
      this->label3 = gcnew System::Windows::Forms::Label;
      this->stateTextBox = gcnew System::Windows::Forms::TextBox;
      this->zipTextBox = gcnew System::Windows::Forms::TextBox;
      
      // Help Label
      this->helpLabel->BorderStyle = System::Windows::Forms::BorderStyle::Fixed3D;
      this->helpLabel->Location = System::Drawing::Point( 8, 80 );
      this->helpLabel->Size = System::Drawing::Size( 272, 72 );
      this->helpLabel->Text = "Click on any control to give it focus, and then press F1 to display help for that control.  Alternately, you can click the help button at the top of the dialog and then click on a control.";
      
      // Address Label
      this->label2->Location = System::Drawing::Point( 16, 8 );
      this->label2->Size = System::Drawing::Size( 100, 16 );
      this->label2->Text = "Address:";
      
      // Comma Label
      this->label3->Location = System::Drawing::Point( 136, 56 );
      this->label3->Size = System::Drawing::Size( 16, 16 );
      this->label3->Text = ", ";
      
      // Address TextBox
      this->addressTextBox->Location = System::Drawing::Point( 16, 24 );
      this->addressTextBox->Size = System::Drawing::Size( 264, 20 );
      this->addressTextBox->TabIndex = 0;
      this->addressTextBox->Tag = "Enter the street address in this text box.";
      this->addressTextBox->Text = "";
      this->addressTextBox->HelpRequested += gcnew System::Windows::Forms::HelpEventHandler( this, &Form1::textBox_HelpRequested );
      
      // City TextBox
      this->cityTextBox->Location = System::Drawing::Point( 16, 48 );
      this->cityTextBox->Size = System::Drawing::Size( 120, 20 );
      this->cityTextBox->TabIndex = 3;
      this->cityTextBox->Tag = "Enter the city here.";
      this->cityTextBox->Text = "";
      this->cityTextBox->HelpRequested += gcnew System::Windows::Forms::HelpEventHandler( this, &Form1::textBox_HelpRequested );
      
      // State TextBox
      this->stateTextBox->Location = System::Drawing::Point( 152, 48 );
      this->stateTextBox->MaxLength = 2;
      this->stateTextBox->Size = System::Drawing::Size( 32, 20 );
      this->stateTextBox->TabIndex = 5;
      this->stateTextBox->Tag = "Enter the state in this text box.";
      this->stateTextBox->Text = "";
      this->stateTextBox->HelpRequested += gcnew System::Windows::Forms::HelpEventHandler( this, &Form1::textBox_HelpRequested );
      
      // Zip TextBox
      this->zipTextBox->Location = System::Drawing::Point( 192, 48 );
      this->zipTextBox->Name = "zipTextBox";
      this->zipTextBox->Size = System::Drawing::Size( 88, 20 );
      this->zipTextBox->TabIndex = 6;
      this->zipTextBox->Tag = "Enter the zip code here.";
      this->zipTextBox->Text = "";
      this->zipTextBox->HelpRequested += gcnew System::Windows::Forms::HelpEventHandler( this, &Form1::textBox_HelpRequested );
      
      // Set up how the form should be displayed and add the controls to the form.
      this->ClientSize = System::Drawing::Size( 292, 160 );
      array<System::Windows::Forms::Control^>^temp0 = {this->zipTextBox,this->stateTextBox,this->label3,this->cityTextBox,this->label2,this->helpLabel,this->addressTextBox};
      this->Controls->AddRange( temp0 );
      this->FormBorderStyle = System::Windows::Forms::FormBorderStyle::FixedDialog;
      this->HelpButton = true;
      this->MaximizeBox = false;
      this->MinimizeBox = false;
      this->Text = "Help Event Demonstration";
   }


private:
   void textBox_HelpRequested( Object^ sender, System::Windows::Forms::HelpEventArgs^ hlpevent )
   {
      
      // This event is raised when the F1 key is pressed or the
      // Help cursor is clicked on any of the address fields.
      // The Help text for the field is in the control's
      // Tag property. It is retrieved and displayed in the label.
      Control^ requestingControl = dynamic_cast<Control^>(sender);
      helpLabel->Text = dynamic_cast<String^>(requestingControl->Tag);
      hlpevent->Handled = true;
   }

};


[STAThread]
int main()
{
   Application::Run( gcnew Form1 );
}

using System;
using System.Drawing;
using System.Windows.Forms;

public class Form1 : System.Windows.Forms.Form
{
    private System.Windows.Forms.TextBox addressTextBox;
    private System.Windows.Forms.Label label2;
    private System.Windows.Forms.TextBox cityTextBox;
    private System.Windows.Forms.Label label3;
    private System.Windows.Forms.TextBox stateTextBox;
    private System.Windows.Forms.TextBox zipTextBox;
    private System.Windows.Forms.Label helpLabel;

    [STAThread]
    static void Main() 
    {
        Application.Run(new Form1());
    }

    public Form1()
    {
        this.addressTextBox = new System.Windows.Forms.TextBox();
        this.helpLabel = new System.Windows.Forms.Label();
        this.label2 = new System.Windows.Forms.Label();
        this.cityTextBox = new System.Windows.Forms.TextBox();
        this.label3 = new System.Windows.Forms.Label();
        this.stateTextBox = new System.Windows.Forms.TextBox();
        this.zipTextBox = new System.Windows.Forms.TextBox();

        // Help Label
        this.helpLabel.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
        this.helpLabel.Location = new System.Drawing.Point(8, 80);
        this.helpLabel.Size = new System.Drawing.Size(272, 72);
        this.helpLabel.Text = "Click on any control to give it focus, and then " +
            "press F1 to display help for that control.  Alternately, you can " +
            "click the help button at the top of the dialog and then click on a control.";

        // Address Label
        this.label2.Location = new System.Drawing.Point(16, 8);
        this.label2.Size = new System.Drawing.Size(100, 16);
        this.label2.Text = "Address:";

        // Comma Label
        this.label3.Location = new System.Drawing.Point(136, 56);
        this.label3.Size = new System.Drawing.Size(16, 16);
        this.label3.Text = ",";

        // Address TextBox
        this.addressTextBox.Location = new System.Drawing.Point(16, 24);
        this.addressTextBox.Size = new System.Drawing.Size(264, 20);
        this.addressTextBox.TabIndex = 0;
        this.addressTextBox.Tag = "Enter the street address in this text box.";
        this.addressTextBox.Text = "";
        this.addressTextBox.HelpRequested += new System.Windows.Forms.HelpEventHandler(this.textBox_HelpRequested);

        // City TextBox
        this.cityTextBox.Location = new System.Drawing.Point(16, 48);
        this.cityTextBox.Size = new System.Drawing.Size(120, 20);
        this.cityTextBox.TabIndex = 3;
        this.cityTextBox.Tag = "Enter the city here.";
        this.cityTextBox.Text = "";
        this.cityTextBox.HelpRequested += new System.Windows.Forms.HelpEventHandler(this.textBox_HelpRequested);

        // State TextBox
        this.stateTextBox.Location = new System.Drawing.Point(152, 48);
        this.stateTextBox.MaxLength = 2;
        this.stateTextBox.Size = new System.Drawing.Size(32, 20);
        this.stateTextBox.TabIndex = 5;
        this.stateTextBox.Tag = "Enter the state in this text box.";
        this.stateTextBox.Text = "";
        this.stateTextBox.HelpRequested += new System.Windows.Forms.HelpEventHandler(this.textBox_HelpRequested);

        // Zip TextBox
        this.zipTextBox.Location = new System.Drawing.Point(192, 48);
        this.zipTextBox.Name = "zipTextBox";
        this.zipTextBox.Size = new System.Drawing.Size(88, 20);
        this.zipTextBox.TabIndex = 6;
        this.zipTextBox.Tag = "Enter the zip code here.";
        this.zipTextBox.Text = "";
        this.zipTextBox.HelpRequested += new System.Windows.Forms.HelpEventHandler(this.textBox_HelpRequested);

        // Set up how the form should be displayed and add the controls to the form.
        this.ClientSize = new System.Drawing.Size(292, 160);
        this.Controls.AddRange(new System.Windows.Forms.Control[] { this.zipTextBox, 
                                this.stateTextBox, this.label3, this.cityTextBox,  
                                this.label2, this.helpLabel, this.addressTextBox});

        this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedDialog;
        this.HelpButton = true;
        this.MaximizeBox = false;
        this.MinimizeBox = false;
        this.Text = "Help Event Demonstration";    
    }

    private void textBox_HelpRequested(object sender, System.Windows.Forms.HelpEventArgs hlpevent)
    {
        // This event is raised when the F1 key is pressed or the
        // Help cursor is clicked on any of the address fields.
        // The Help text for the field is in the control's
        // Tag property. It is retrieved and displayed in the label.

        Control requestingControl = (Control)sender;
        helpLabel.Text = (string)requestingControl.Tag;
        hlpevent.Handled = true;
    }
}

Imports System.Drawing
Imports System.Windows.Forms

Public Class Form1
    Inherits System.Windows.Forms.Form
    Private WithEvents addressTextBox As System.Windows.Forms.TextBox
    Private WithEvents label2 As System.Windows.Forms.Label
    Private WithEvents cityTextBox As System.Windows.Forms.TextBox
    Private WithEvents label3 As System.Windows.Forms.Label
    Private WithEvents stateTextBox As System.Windows.Forms.TextBox
    Private WithEvents zipTextBox As System.Windows.Forms.TextBox
    Private WithEvents helpLabel As System.Windows.Forms.Label

    <STAThread()> _
    Shared Sub Main()
        Application.Run(New Form1)
    End Sub

    Public Sub New()
        Me.addressTextBox = New System.Windows.Forms.TextBox
        Me.helpLabel = New System.Windows.Forms.Label
        Me.label2 = New System.Windows.Forms.Label
        Me.cityTextBox = New System.Windows.Forms.TextBox
        Me.label3 = New System.Windows.Forms.Label
        Me.stateTextBox = New System.Windows.Forms.TextBox
        Me.zipTextBox = New System.Windows.Forms.TextBox

        ' Help Label
        Me.helpLabel.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
        Me.helpLabel.Location = New System.Drawing.Point(8, 80)
        Me.helpLabel.Size = New System.Drawing.Size(272, 72)
        Me.helpLabel.Text = "Click on any control to give it focus, and then " & _
            "press F1 to display help for that" + " control.  Alternately, you can " & _
            "click the help button at the top of the dialog and then click on a control."

        ' Address Label
        Me.label2.Location = New System.Drawing.Point(16, 8)
        Me.label2.Size = New System.Drawing.Size(100, 16)
        Me.label2.Text = "Address:"

        ' Comma Label
        Me.label3.Location = New System.Drawing.Point(136, 56)
        Me.label3.Size = New System.Drawing.Size(16, 16)
        Me.label3.Text = ","

        ' Address TextBox
        Me.addressTextBox.Location = New System.Drawing.Point(16, 24)
        Me.addressTextBox.Size = New System.Drawing.Size(264, 20)
        Me.addressTextBox.TabIndex = 0
        Me.addressTextBox.Tag = "Enter the stree address in this text box."
        Me.addressTextBox.Text = ""

        ' City TextBox
        Me.cityTextBox.Location = New System.Drawing.Point(16, 48)
        Me.cityTextBox.Size = New System.Drawing.Size(120, 20)
        Me.cityTextBox.TabIndex = 3
        Me.cityTextBox.Tag = "Enter the city here."
        Me.cityTextBox.Text = ""

        ' State TextBox
        Me.stateTextBox.Location = New System.Drawing.Point(152, 48)
        Me.stateTextBox.MaxLength = 2
        Me.stateTextBox.Size = New System.Drawing.Size(32, 20)
        Me.stateTextBox.TabIndex = 5
        Me.stateTextBox.Tag = "Enter the state in this text box."
        Me.stateTextBox.Text = ""

        ' Zip TextBox
        Me.zipTextBox.Location = New System.Drawing.Point(192, 48)
        Me.zipTextBox.Size = New System.Drawing.Size(88, 20)
        Me.zipTextBox.TabIndex = 6
        Me.zipTextBox.Tag = "Enter the zip code here."
        Me.zipTextBox.Text = ""

        ' Set up how the form should be displayed and add the controls to the form.
        Me.ClientSize = New System.Drawing.Size(292, 160)
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.zipTextBox, _
                                Me.stateTextBox, Me.label3, Me.cityTextBox, _
                                Me.label2, Me.helpLabel, Me.addressTextBox})
        Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedDialog
        Me.HelpButton = True
        Me.MaximizeBox = False
        Me.MinimizeBox = False
        Me.Text = "Help Event Demonstration"
    End Sub

    Private Sub textBox_HelpRequested(ByVal sender As Object, ByVal hlpevent As System.Windows.Forms.HelpEventArgs) Handles addressTextBox.HelpRequested, cityTextBox.HelpRequested, stateTextBox.HelpRequested, zipTextBox.HelpRequested
        ' This event is raised when the F1 key is pressed or the
        ' Help cursor is clicked on any of the address fields.
        ' The Help text for the field is in the control's
        ' Tag property. It is retrieved and displayed in the label.

        Dim requestingControl As Control = CType(sender, Control)
        helpLabel.Text = CStr(requestingControl.Tag)
        hlpevent.Handled = True

    End Sub
End Class

Comentarios

El HelpRequested evento se produce cuando el usuario solicita ayuda para un control. Un HelpEventArgs objeto especifica las coordenadas de pantalla del puntero del mouse y si se controló el evento.

Para obtener información sobre el modelo de eventos, vea Control y generación de eventos.

Constructores

HelpEventArgs(Point)

Inicializa una nueva instancia de la clase HelpEventArgs.

Propiedades

Handled	Obtiene o establece un valor que indica si se controló el evento de ayuda.
MousePos	Obtiene las coordenadas de pantalla del puntero del mouse.

Métodos

Equals(Object)	Determina si el objeto especificado es igual que el objeto actual. (Heredado de Object)
GetHashCode()	Sirve como la función hash predeterminada. (Heredado de Object)
GetType()	Obtiene el Type de la instancia actual. (Heredado de Object)
MemberwiseClone()	Crea una copia superficial del Object actual. (Heredado de Object)
ToString()	Devuelve una cadena que representa el objeto actual. (Heredado de Object)

Consulte también

• Help
• HelpProvider