PrintDocument.PrintPage Evento

Definizione

Spazio dei nomi:

System.Drawing.Printing

Assembly:

System.Drawing.Common.dll

Pacchetto:

System.Drawing.Common v8.0.0

Origine:

PrintDocument.cs

Si verifica quando è necessario disporre dell'output da stampare per la pagina corrente.

public:
 event System::Drawing::Printing::PrintPageEventHandler ^ PrintPage;

public event System.Drawing.Printing.PrintPageEventHandler PrintPage;

member this.PrintPage : System.Drawing.Printing.PrintPageEventHandler 

Public Custom Event PrintPage As PrintPageEventHandler 

Tipo evento

PrintPageEventHandler

Esempio

Nell'esempio di codice seguente viene illustrata la gestione dell'evento PrintPage .

Per un altro esempio, vedere Procedura: Stampare un file di testo a più pagine in Windows Forms.

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

using namespace System;
using namespace System::IO;
using namespace System::Drawing;
using namespace System::Drawing::Printing;
using namespace System::Windows::Forms;

public ref class PrintingExample: public System::Windows::Forms::Form
{
private:
   System::ComponentModel::Container^ components;
   System::Windows::Forms::Button^ printButton;
   System::Drawing::Font^ printFont;
   StreamReader^ streamToPrint;

public:
   PrintingExample()
      : Form()
   {
      
      // The Windows Forms Designer requires the following call.
      InitializeComponent();
   }


private:

   // The Click event is raised when the user clicks the Print button.
   void printButton_Click( Object^ /*sender*/, EventArgs^ /*e*/ )
   {
      try
      {
         streamToPrint = gcnew StreamReader( "C:\\My Documents\\MyFile.txt" );
         try
         {
            printFont = gcnew System::Drawing::Font( "Arial",10 );
            PrintDocument^ pd = gcnew PrintDocument;
            pd->PrintPage += gcnew PrintPageEventHandler( this, &PrintingExample::pd_PrintPage );
            pd->Print();
         }
         finally
         {
            streamToPrint->Close();
         }

      }
      catch ( Exception^ ex ) 
      {
         MessageBox::Show( ex->Message );
      }

   }


   // The PrintPage event is raised for each page to be printed.
   void pd_PrintPage( Object^ /*sender*/, PrintPageEventArgs^ ev )
   {
      float linesPerPage = 0;
      float yPos = 0;
      int count = 0;
      float leftMargin = (float)ev->MarginBounds.Left;
      float topMargin = (float)ev->MarginBounds.Top;
      String^ line = nullptr;
      
      // Calculate the number of lines per page.
      linesPerPage = ev->MarginBounds.Height / printFont->GetHeight( ev->Graphics );
      
      // Print each line of the file.
      while ( count < linesPerPage && ((line = streamToPrint->ReadLine()) != nullptr) )
      {
         yPos = topMargin + (count * printFont->GetHeight( ev->Graphics ));
         ev->Graphics->DrawString( line, printFont, Brushes::Black, leftMargin, yPos, gcnew StringFormat );
         count++;
      }

      
      // If more lines exist, print another page.
      if ( line != nullptr )
            ev->HasMorePages = true;
      else
            ev->HasMorePages = false;
   }


   // The Windows Forms Designer requires the following procedure.
   void InitializeComponent()
   {
      this->components = gcnew System::ComponentModel::Container;
      this->printButton = gcnew System::Windows::Forms::Button;
      this->ClientSize = System::Drawing::Size( 504, 381 );
      this->Text = "Print Example";
      printButton->ImageAlign = System::Drawing::ContentAlignment::MiddleLeft;
      printButton->Location = System::Drawing::Point( 32, 110 );
      printButton->FlatStyle = System::Windows::Forms::FlatStyle::Flat;
      printButton->TabIndex = 0;
      printButton->Text = "Print the file.";
      printButton->Size = System::Drawing::Size( 136, 40 );
      printButton->Click += gcnew System::EventHandler( this, &PrintingExample::printButton_Click );
      this->Controls->Add( printButton );
   }

};


// This is the main entry point for the application.
int main()
{
   Application::Run( gcnew PrintingExample );
}

using System;
using System.IO;
using System.Drawing;
using System.Drawing.Printing;
using System.Windows.Forms;

public partial class Form1 : System.Windows.Forms.Form
{
    private System.ComponentModel.Container components;
    private System.Windows.Forms.Button printButton;
    private Font printFont;
    private StreamReader streamToPrint;

    public Form1()
    {
        // The Windows Forms Designer requires the following call.
        InitializeComponent();
    }

    // The Click event is raised when the user clicks the Print button.
    private void printButton_Click(object sender, EventArgs e)
    {
        try
        {
            streamToPrint = new StreamReader
               ("C:\\My Documents\\MyFile.txt");
            try
            {
                printFont = new Font("Arial", 10);
                PrintDocument pd = new PrintDocument();
                pd.PrintPage += new PrintPageEventHandler
                   (this.pd_PrintPage);
                pd.Print();
            }
            finally
            {
                streamToPrint.Close();
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
    }

    // The PrintPage event is raised for each page to be printed.
    private void pd_PrintPage(object sender, PrintPageEventArgs ev)
    {
        float linesPerPage = 0;
        float yPos = 0;
        int count = 0;
        float leftMargin = ev.MarginBounds.Left;
        float topMargin = ev.MarginBounds.Top;
        string line = null;

        // Calculate the number of lines per page.
        linesPerPage = ev.MarginBounds.Height /
           printFont.GetHeight(ev.Graphics);

        // Print each line of the file.
        while (count < linesPerPage &&
           ((line = streamToPrint.ReadLine()) != null))
        {
            yPos = topMargin + (count *
               printFont.GetHeight(ev.Graphics));
            ev.Graphics.DrawString(line, printFont, Brushes.Black,
               leftMargin, yPos, new StringFormat());
            count++;
        }

        // If more lines exist, print another page.
        if (line != null)
            ev.HasMorePages = true;
        else
            ev.HasMorePages = false;
    }

    // The Windows Forms Designer requires the following procedure.
    private void InitializeComponent()
    {
        this.components = new System.ComponentModel.Container();
        this.printButton = new System.Windows.Forms.Button();

        this.ClientSize = new System.Drawing.Size(504, 381);
        this.Text = "Print Example";

        printButton.ImageAlign =
           System.Drawing.ContentAlignment.MiddleLeft;
        printButton.Location = new System.Drawing.Point(32, 110);
        printButton.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
        printButton.TabIndex = 0;
        printButton.Text = "Print the file.";
        printButton.Size = new System.Drawing.Size(136, 40);
        printButton.Click += new System.EventHandler(printButton_Click);

        this.Controls.Add(printButton);
    }
}

Imports System.IO
Imports System.Drawing
Imports System.Drawing.Printing
Imports System.Windows.Forms

Public Class Form1
    Inherits System.Windows.Forms.Form
    Private WithEvents printButton As System.Windows.Forms.Button
    Private printFont As Font
    Private streamToPrint As StreamReader

    Public Sub New()
        ' The Windows Forms Designer requires the following call.
        InitializeComponent()
        InitializeForm()
    End Sub

    ' The Click event is raised when the user clicks the Print button.
    Private Sub printButton_Click(ByVal sender As Object, ByVal e As EventArgs) Handles printButton.Click
        Try
            streamToPrint = New StreamReader("C:\My Documents\MyFile.txt")
            Try
                printFont = New Font("Arial", 10)
                Dim pd As New PrintDocument()
                AddHandler pd.PrintPage, AddressOf Me.pd_PrintPage
                pd.Print()
            Finally
                streamToPrint.Close()
            End Try
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
    End Sub

    ' The PrintPage event is raised for each page to be printed.
    Private Sub pd_PrintPage(ByVal sender As Object, ByVal ev As PrintPageEventArgs)
        Dim linesPerPage As Single = 0
        Dim yPos As Single = 0
        Dim count As Integer = 0
        Dim leftMargin As Single = ev.MarginBounds.Left
        Dim topMargin As Single = ev.MarginBounds.Top
        Dim line As String = Nothing

        ' Calculate the number of lines per page.
        linesPerPage = ev.MarginBounds.Height / printFont.GetHeight(ev.Graphics)

        ' Print each line of the file.
        While count < linesPerPage
            line = streamToPrint.ReadLine()
            If line Is Nothing Then
                Exit While
            End If
            yPos = topMargin + count * printFont.GetHeight(ev.Graphics)
            ev.Graphics.DrawString(line, printFont, Brushes.Black, leftMargin, yPos, New StringFormat())
            count += 1
        End While

        ' If more lines exist, print another page.
        If (line IsNot Nothing) Then
            ev.HasMorePages = True
        Else
            ev.HasMorePages = False
        End If
    End Sub

    Private Sub InitializeForm()
        Me.components = New System.ComponentModel.Container()
        Me.printButton = New System.Windows.Forms.Button()

        Me.ClientSize = New System.Drawing.Size(504, 381)
        Me.Text = "Print Example"

        printButton.ImageAlign = System.Drawing.ContentAlignment.MiddleLeft
        printButton.Location = New System.Drawing.Point(32, 110)
        printButton.FlatStyle = System.Windows.Forms.FlatStyle.Flat
        printButton.TabIndex = 0
        printButton.Text = "Print the file."
        printButton.Size = New System.Drawing.Size(136, 40)
        AddHandler printButton.Click, AddressOf printButton_Click

        Me.Controls.Add(printButton)
    End Sub


    ' This is the main entry point for the application.    
    Public Shared Sub Main()
        Application.Run(New Form1())
    End Sub

End Class

Commenti

Per specificare l'output da stampare, utilizzare la proprietà Graphics di PrintPageEventArgs. Ad esempio, per specificare una riga di testo da stampare, disegnare il testo usando il Graphics.DrawString metodo .

Oltre a specificare l'output, è possibile indicare se sono presenti pagine aggiuntive da stampare impostando la PrintPageEventArgs.HasMorePages proprietà su true. Il valore predefinito è false, che indica che non sono presenti più pagine da stampare. È anche possibile modificare le singole impostazioni di pagina tramite PageSettings e il processo di stampa può essere annullato impostando la PrintPageEventArgs.Cancel proprietà su true. Per stampare ogni pagina di un documento utilizzando impostazioni di pagina diverse, gestire l'evento QueryPageSettings .

Per associare l'evento al gestore eventi, aggiungere un'istanza del PrintPageEventHandler delegato all'evento. Il gestore eventi viene chiamato ogni volta che si verifica l'evento. Per altre informazioni sulla gestione degli eventi con delegati, vedere Gestione e generazione di eventi.

Vedi anche

• PrintPageEventHandler
• PrintPageEventArgs
• BeginPrint
• EndPrint
• QueryPageSettings
• Graphics
• Procedura: Stampare un file di testo con più pagine in Windows Form
• Supporto per la stampa in Windows Form