Posted on 2007-07-12 19:10
kooyee 阅读(1512)
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GUI骨衣
//Send questions, comments, bug reports, etc. to the authors:
//Rob Warner (rwarner@interspatial.com)
//Robert Harris (rbrt_harris@yahoo.com)
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.printing.*;
import org.eclipse.swt.widgets.*;
/** *//**
* This class demonstrates printing images
*/
public class ImagePrinterExample 
{
/** *//**
* The application entry point
* @param args the command line arguments
*/
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display, SWT.NONE);
try {
// Prompt the user for an image file
FileDialog fileChooser = new FileDialog(shell, SWT.OPEN);
String fileName = fileChooser.open();
if (fileName == null) { return; }
// Load the image
ImageLoader loader = new ImageLoader();
ImageData[] imageData = loader.load(fileName);
if (imageData.length > 0) {
// Show the Choose Printer dialog
PrintDialog dialog = new PrintDialog(shell, SWT.NULL);
PrinterData printerData = dialog.open();
if (printerData != null) {
// Create the printer object
Printer printer = new Printer(printerData);
// Calculate the scale factor between the screen resolution and printer
// resolution in order to correctly size the image for the printer
Point screenDPI = display.getDPI();
Point printerDPI = printer.getDPI();
int scaleFactor = printerDPI.x / screenDPI.x;
// Determine the bounds of the entire area of the printer
Rectangle trim = printer.computeTrim(0, 0, 0, 0);
// Start the print job
if (printer.startJob(fileName)) {
if (printer.startPage()) {
GC gc = new GC(printer);
Image printerImage = new Image(printer, imageData[0]);
// Draw the image
gc.drawImage(printerImage, 0, 0, imageData[0].width,
imageData[0].height, -trim.x, -trim.y,
scaleFactor * imageData[0].width,
scaleFactor * imageData[0].height);
// Clean up
printerImage.dispose();
gc.dispose();
printer.endPage();
}
}
// End the job and dispose the printer
printer.endJob();
printer.dispose();
}
}
} catch (Exception e) {
MessageBox messageBox = new MessageBox(shell, SWT.ICON_ERROR);
messageBox.setMessage("Error printing test image");
messageBox.open();
}
}
}
和打印文字不同。因为系统中的dpi(dot per inch)和打印机的dpi不同，所以要进行转换。