print barcode vb.net CHA PTE R 18 in Visual C#

Print Data Matrix ECC200 in Visual C# CHA PTE R 18

These event handlers establish the required printing support for the parent form. The printing logic for the child form is presented next. 18.1.2 DRAWING A PRINT PAGE With our user interface logic in place, we are ready to implement the printing of a page. This is done using the PrintPageEventArgs parameter provided to the PrintPage event handler. This class is summarized in .NET Table 18.1.

The PrintPageEventArgs class represents an event argument containing information required for printing pages to a printer. This class is part of the System.Drawing.Printing namespace, and inherits from the System.EventArgs class. Cancel Gets or sets whether the print job should be cancelled. Gets the Graphics object on which to paint the page to print. Gets or sets whether an additional page should be printed after the current one. Gets the printable area of a page, which is the rectangle within the margins of the page. Gets the page area, which is the rectangle representing the entire page. Gets the PageSettings object representing the settings for the current page.

We will implement a PrintCurrentImage method in the MainForm class to make use of this parameter. Internally, this will draw the photograph using the provided Graphics object, and use an internal PrintTextString method to draw the individual properties for the photograph.

IMPLEMENT THE PRINTCURRENTIMAGE METHOD Action 1 In the MainForm.cs code window, indicate that we will use members of the

using System.Drawing.Printing;

namespace. 2 Add a PrintCurrentImage method that accepts a PrintPageEventArgs object as a parameter.

public void PrintCurrentImage (PrintPageEventArgs e) {

IMPLEMENT THE PRINTCURRENTIMAGE METHOD (continued) Action 3 If there is no current photo, then abort the print operation. Result

Photograph photo = _album.CurrentPhoto; if (photo == null) { // nothing to print, so abort e.Cancel = true; return; } // Establish some useful shortcuts float leftMargin = e.MarginBounds.Left; float rightMargin = e.MarginBounds.Right; float topMargin = e.MarginBounds.Top; float bottomMargin = e.MarginBounds.Bottom; float printableWidth = e.MarginBounds.Width; float printableHeight = e.MarginBounds.Height; Graphics g = e.Graphics; Font printFont = new Font("Times New Roman", 11); float fontHeight = printFont.GetHeight(g); float spaceWidth = g.MeasureString(" ", printFont).Width;

Create a Font object: a. Use 11 point Times New Roman. b. Use the GetHeight method to determine the height of each line of text. c. Use the MeasureString method to determine the size of a space.

Determine the correct length so that the image can be drawn into a box which is 75% of the shortest side of the page. Note: This logic accounts for both landscape and portrait page orientation. The xPos and yPos variables represent where the first line of text should be drawn.

// Draw image in box 75% of shortest side float imageBoxLength; float xPos = leftMargin; float yPos = topMargin + fontHeight; if (printableWidth < printableHeight) { imageBoxLength = printableWidth * 75/100; yPos += imageBoxLength; } else { imageBoxLength = printableHeight * 75/100; xPos += imageBoxLength + spaceWidth; } // Draw image at start of the page Rectangle imageBox = new Rectangle((int)leftMargin + 1, (int)topMargin + 1, (int)imageBoxLength, (int)imageBoxLength); g.DrawImage(photo.Image, photo.ScaleToFit(imageBox)); // Determine rectangle for text RectangleF printArea = new RectangleF(xPos, yPos, rightMargin - xPos, bottomMargin - yPos);

IMPLEMENT THE PRINTCURRENTIMAGE METHOD (continued) Action 9 Print the file name, caption, photographer, and notes properties for the photograph onto the page.

PrintTextString(g, printFont, "FileName:", photo.FileName, ref printArea); PrintTextString(g, printFont, "Caption:", photo.Caption, ref printArea); PrintTextString(g, printFont, "Photographer:", photo.Photographer, ref printArea); PrintTextString(g, printFont, "Notes:", photo.Notes, ref printArea); }

The PrintTextString method is implemented by the subsequent steps. Note that our implementation prints the given string across multiple lines if necessary by drawing each word in the text string separately. Also note that the printArea variable is passed by reference. This is required in order to modify the printable area for text strings in the PrintTextString method. Since the RectangleF structure is a value type, it is normally passed by value.

IMPLEMENT THE PRINTTEXTSTRING METHOD Action 10 Add a PrintTextString method to the MainForm.cs code window. Result

protected void PrintTextString( Graphics g, Font printFont, string name, string text, ref RectangleF printArea) { // Establish some useful shortcuts float leftMargin = printArea.Left; float rightMargin = printArea.Right; float topMargin = printArea.Top; float bottomMargin = printArea.Bottom; float fontHeight = printFont.GetHeight(g); float xPos = printArea.Left; float yPos = topMargin + fontHeight; float spaceWidth = g.MeasureString(" ", printFont).Width; float nameWidth = g.MeasureString(name, printFont).Width; if (!printArea.Contains(xPos + nameWidth, yPos)) { // Does not fit, so abort return; }

Create some local variables for the margins of the printable area. Also determine the height of the font and the coordinates where the text should be drawn. Find the width of a space and the name for the text string.