Print preview consists of displaying, on the computer monitor, a sample representation of what the document would look like once printed.

Print preview is primarily a technique of drawing a sample printed sheet on a form. It is implemented by the PrintPreviewDialog button from the Toolbox. Therefore, at design time, to provide print preview, from the Printing section of the Toolbox and click the form. As its name indicates, the dialog box is already created but like the other dialog boxes of the .NET Framework, you must add it to a form in order to make it available in your application.

In the .NET Framework, print preview is implemented through the PrintPreviewDialog class. This class is derived from the Form class. Based on this, to programmatically create a print preview, you can start by declaring a variable of type PrintPreviewDialog. Here is an example:

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

public class Exercise : Form
{
    Button btnPrintPreview;

    public Exercise()
    {
        InitializeComponent();
    }

    void InitializeComponent()
    {
        btnPrintPreview = new Button();
        btnPrintPreview.Location = new Point(12, 12);
        btnPrintPreview.Text = "&Print Preview...";
        btnPrintPreview.Width = 100;
        btnPrintPreview.Click += new EventHandler(PreviewDocumentClick);

        Controls.Add(btnPrintPreview);
    }

    void PreviewDocumentClick(object sender, EventArgs e)
    {
        PrintPreviewDialog dlgPrint = new PrintPreviewDialog();
    }
}

public class Program
{
    static int Main()
    {
        System.Windows.Forms.Application.Run(new Exercise());
        return 0;
    }
}

As a dialog-based object, to display the print preview, the PrintPreviewDialog class inherits the ShowDialog() method from its parent the Form class. Here is an example:

void PreviewDocumentClick(object sender, EventArgs e)
{
        PrintPreviewDialog dlgPrintPreview = new PrintPreviewDialog();

        dlgPrintPreview.ShowDialog();
}

This would produce: