Control.HelpRequested Evento
Definición
Importante
Parte de la información hace referencia a la versión preliminar del producto, que puede haberse modificado sustancialmente antes de lanzar la versión definitiva. Microsoft no otorga ninguna garantía, explícita o implícita, con respecto a la información proporcionada aquí.
Se produce cuando el usuario solicita ayuda para un control.
public:
event System::Windows::Forms::HelpEventHandler ^ HelpRequested;public event System.Windows.Forms.HelpEventHandler HelpRequested;public event System.Windows.Forms.HelpEventHandler? HelpRequested;member this.HelpRequested : System.Windows.Forms.HelpEventHandler Public Custom Event HelpRequested As HelpEventHandler Tipo de evento
Ejemplos
En el ejemplo de código 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
Normalmente HelpRequested , el evento se genera cuando el usuario presiona la tecla F1 o se hace clic en un botón de ayuda contextual asociado.
Para obtener más información sobre el manejo de eventos, consulte controlar y provocar eventos.
Se aplica a
Consulte también
Colaborar con nosotros en GitHub
El origen de este contenido se puede encontrar en GitHub, donde también puede crear y revisar problemas y solicitudes de incorporación de cambios. Para más información, consulte nuestra guía para colaboradores.
