Printable ListView

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Introduction

Some time during my development works I had the need of printing the contents of a ListView control. So I wrote down the code for a custom control, named PrintableListView, that solved the following two problems:

• extend the print on multiple pages when the width of the list exceeds the width of the print page,
• shrink, optionally, the list in a way that the resulting width fits on a single page.

Using the code

PrintableListView control is derived from System.Windows.Forms.ListView, so use it like the native ListView control. The additional functionalities are those for print and for print preview.

// call the print method for displaying the standard print dialog.

this.m_list.Print();


// call the print preview method for displaying

// the standard print preview dialog

this.m_list.PrintPreview();

To turn on the �Fit to page� option, use the FitToPage property of the control.

this.m_list.FitToPage = true;

To set the title that appears on the page header, use the Title property of the control.

Points of Interest

If you think about the ListView control, you will note that we have all the information we need to print it in the simplest way. We have the columns width, the fonts, the rows height and so on. All we have to do is to get all these information and play a little with the Graphics instance that represents the printing surface. What follows is the way I solved the problems listed in the Introduction.

Multi page print

This is quite simple. When we are printing the current column of a row, we check whether there is enough room to print it. If not, we mark that column as the first one for the next page. That�s it.

Fit to page

This point is just a little bit more complex compared to the previous one. If the total width of the list is greater than the width of the available space, we have to calculate a scaling factor, given by the list width divided by the available space. For simplicity, in my implementation, I converted all the measures in units of hundredths of an inch. To set the scale factor and unit of measure is sufficient to change the coordinate system of the Graphics object passed to the handler of the PrintPage event of the PrintDocument object.

private void OnPrintPage(object sender, PrintPageEventArgs e)
{
    �
    if (m_nStartCol==0 && m_bFitToPage && m_fListWidth>rectBody.Width)
    {
        // Calculate scale factor

        fScale = rectBody.Width / m_fListWidth;
    }
    �
    �
    // Setting scale factor and unit of measure

    g.ScaleTransform(fScale, fScale);
    g.PageUnit = GraphicsUnit.Inch;
    g.PageScale = 0.01f;
    �
}