HelpEventHandler Delegasikan

Definisi

Ruang nama:

System.Windows.Forms

Rakitan:

System.Windows.Forms.dll

Mewakili metode yang akan menangani HelpRequested peristiwa Control.

public delegate void HelpEventHandler(System::Object ^ sender, HelpEventArgs ^ hlpevent);

public delegate void HelpEventHandler(object? sender, HelpEventArgs hlpevent);

type HelpEventHandler = delegate of obj * HelpEventArgs -> unit

Public Delegate Sub HelpEventHandler(sender As Object, hlpevent As HelpEventArgs)

Parameter

sender

Object

Sumber dari peristiwa tersebut.

hlpevent

HelpEventArgs

HelpEventArgs yang berisi data peristiwa.

Contoh

Contoh berikut menunjukkan penanganan HelpRequested peristiwa untuk menampilkan konten Bantuan kustom pada formulir yang berisi empat bidang alamat. Peristiwa HelpRequested dimunculkan baik dengan menekan tombol F1 dengan fokus di bidang alamat, atau dengan menggunakan tombol Bantuan peka konteks dan mengklik kursor Bantuan pada bidang alamat. Properti Handled diatur ke true untuk menunjukkan bahwa peristiwa ditangani HelpRequested . Contohnya juga menunjukkan penyimpanan teks Bantuan di Control.Tag properti .

#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

Keterangan

Saat membuat HelpEventHandler delegasi, Anda mengidentifikasi metode yang akan menangani peristiwa. Untuk mengaitkan peristiwa dengan penanganan aktivitas Anda, tambahkan instans delegasi ke peristiwa. Penanganan aktivitas dipanggil setiap kali peristiwa terjadi, kecuali Jika Anda menghapus delegasi. Untuk informasi selengkapnya tentang menangani peristiwa dengan delegasi, lihat Menangani dan Meningkatkan Peristiwa.

Metode Ekstensi

Lihat juga

• HelpRequested
• HelpEventArgs