Printing Selected Columns and Rows in a DataGrid

Introduction

Existing articles about DataGrid printing can only print all columns and rows. Sometimes a user needs to print specific columns and rows in a DataGrid. Some cases can be as below:

There are a very high number of rows in a DataGrid and there is no need to print all of them.
Sum of the column widths may be longer than the page width and it is better to remove one or more columns while printing.
The user wants to filter the DataGrid contents and then print the filtered data.

So a class named PrintDG was implemented, and it can be used in an application. I have done it both for DataGrid and DataGridView, in C# and VB.NET.

Description

The main section of the code is the PrintDG class.

In the PrintDG, we have:

The SelectedColumns and AvailableColumns lists to hold column names.
A PrintDocument object named PrintDoc (with BeginPrint and PrintPage events handlers).
Four functions:
- Print_DataGrid: The main function that can be called from outside of the class.
- PrintDoc_BeginPrint: Initializes some variables to begin printing.
- PrintDoc_PrintPage: Performs the printing job.
- DrawFooter: Writes the page number.

Using the code

For using the PrintDG class, the DataGrid must have a TableSyle, dg.TableStyles[0]. In the Main Form, the DataGrid is filled with the 'Order' table of 'Northwind.mdb', and a TableStyle for the DataGrid is defined. In the PrintOption Form, the DataGrid columns, font, fore-color, and title can be selected by the user.

Here is a section of code in the PrintDoc_PrintPage event handler. It does the following tasks:

Loops through all rows in the DataView.
In the 'Print Selected Rows' mode, if current row not selected, then ignore it.
If it reaches the end of the page, then write page number and go to the next page. If it doesn't reach the end of page then:
If it is in a new page, then draw headers and columns (it checks to see if each column was selected by the user, if not, will skip it).
Draw the column contents for the TextBoxColumn and BoolColumn (it checks to see if each column was selected by the user, if not, will skip it)
Draw the borders.
Calculate 'Rows per Page' for the first page.

// Print Current Page, Row by Row 
while (RowPos <= dv.Count - 1)
{
    if (!PrintAllRows && !dg.IsSelected(RowPos))
    {
        RowPos++;
        continue;
    }
    DataRowView oRow = dv[RowPos];
    if (nTop + nHeight >= e.MarginBounds.Height + e.MarginBounds.Top)
    {
        DrawFooter(e, RowsPerPage);
        NewPage = true;
        PageNo++;
        e.HasMorePages = true;
        return;
    }
    else
    {
        if (NewPage)
        {
            // Draw Header
            e.Graphics.DrawString(PrintTitle, 
                    new Font(PrintFont, FontStyle.Bold), 
                    Brushes.Black, e.MarginBounds.Left, 
                    e.MarginBounds.Top -
                    e.Graphics.MeasureString(PrintTitle, 
                    new Font(PrintFont, FontStyle.Bold), 
                    e.MarginBounds.Width).Height - 13);

            string s = DateTime.Now.ToLongDateString() + " " + 
                       DateTime.Now.ToShortTimeString();
            e.Graphics.DrawString(s, new Font(PrintFont, 
                    FontStyle.Bold), Brushes.Black, 
                    e.MarginBounds.Left + (e.MarginBounds.Width - 
                    e.Graphics.MeasureString(s, 
                    new Font(PrintFont, FontStyle.Bold), 
                    e.MarginBounds.Width).Width), e.MarginBounds.Top - 
                    e.Graphics.MeasureString(PrintTitle, 
                    new Font(new Font(PrintFont, FontStyle.Bold), 
                    FontStyle.Bold),
                    e.MarginBounds.Width).Height - 13);

            // Draw Columns
            nTop = e.MarginBounds.Top;
            i = 0;
            foreach (DataGridColumnStyle GridCol in 
                     dg.TableStyles[0].GridColumnStyles)
            {
                if (!PrintDG.SelectedColumns.Contains(GridCol.HeaderText))
                    continue;
                e.Graphics.FillRectangle(new SolidBrush(Color.LightGray), 
                        new Rectangle((int) ColumnLefts[i], 
                        nTop, (int) ColumnWidths[i], nHeight));
                e.Graphics.DrawRectangle(Pens.Black, 
                         new Rectangle((int) ColumnLefts[i], nTop,
                        (int) ColumnWidths[i], nHeight));
                e.Graphics.DrawString(GridCol.HeaderText, PrintFont, 
                        new SolidBrush(PrintFontColor), 
                        new RectangleF((int) ColumnLefts[i],nTop, 
                        (int) ColumnWidths[i], nHeight), StrFormat);

                i++;
            }
            NewPage = false;
        }
        nTop += nHeight;
        i = 0;
        // Draw Columns Contents
        foreach (DataGridColumnStyle oColumn in 
                 dg.TableStyles[0].GridColumnStyles)
        {
            if (!PrintDG.SelectedColumns.Contains(oColumn.HeaderText))
                continue;
            string cellval = oRow.Row[oColumn.MappingName].ToString().Trim();
            if (ColumnTypes[i].ToString() == 
               "System.Windows.Forms.DataGridTextBoxColumn")
            {
                // For the TextBox Column
                // Draw Content of TextBox Cell
                e.Graphics.DrawString(cellval, PrintFont, 
                        new SolidBrush(PrintFontColor),
                        new RectangleF((int) ColumnLefts[i], nTop, 
                        (int) ColumnWidths[i], nHeight), StrFormat);
            }
            else if (ColumnTypes[i].ToString() == 
                     "System.Windows.Forms.DataGridBoolColumn")
            {
                // For the CheckBox Column
                // Draw Content of CheckBox Cell
                ChkBox.Size = new Size(14, 14);
                ChkBox.Checked = (bool) (oRow.Row[oColumn.MappingName]);
                Bitmap oBitmap = new Bitmap((int) ColumnWidths[i], nHeight);
                Graphics oTempGraphics = Graphics.FromImage(oBitmap);
                oTempGraphics.FillRectangle(Brushes.White, 
                   new Rectangle(0, 0, oBitmap.Width, oBitmap.Height));
                ChkBox.DrawToBitmap(oBitmap, 
                        new Rectangle((int)((oBitmap.Width - ChkBox.Width) / 2), 
                        (int) ((oBitmap.Height - ChkBox.Height) / 2), 
                        ChkBox.Width, ChkBox.Height));
                e.Graphics.DrawImage(oBitmap, 
                  new Point((int) ColumnLefts[i], nTop));
            }
            e.Graphics.DrawRectangle(Pens.Black, 
                       new Rectangle((int) ColumnLefts[i], 
                       nTop, (int) ColumnWidths[i], nHeight));
            i++;
        }
    }
    RowPos++;
    // For the first page it calculates Rows per Page
    if (PageNo == 1) RowsPerPage++;
}

History

December 12, 2006: Bug fixed - When there is no selected row, then trying to set 'Rows to print' = 'Selected rows' might cause 'Division by zero' error message. (Thanks to khanhdl.)

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