我在這裏試圖製作一個鞦韆應用程序。現在我的目標是打印收據。我已經建立了關於JPanel的所有細節。我試圖在java中打印JPanel,但它打印一個空白文檔。如何在java中打印jpanel?
在JPanel的我想打印: 代碼:
1.ActionListener
btnPrint.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
PrinterJob pjob = PrinterJob.getPrinterJob();
PageFormat preformat = pjob.defaultPage();
preformat.setOrientation(PageFormat.LANDSCAPE);
PageFormat postformat = pjob.pageDialog(preformat);
//If user does not hit cancel then print.
if (preformat != postformat) {
//Set print component
pjob.setPrintable(new Printer(printPanel), postformat);
if (pjob.printDialog()) {
try {
pjob.print();
} catch (PrinterException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
});
2.打印機類:
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.print.PageFormat;
import java.awt.print.Printable;
import java.awt.print.PrinterException;
public class Printer implements Printable {
final Component comp;
public Printer(Component comp){
this.comp = comp;
}
@Override
public int print(Graphics g, PageFormat format, int page_index)
throws PrinterException {
if (page_index > 0) {
return Printable.NO_SUCH_PAGE;
}
// get the bounds of the component
Dimension dim = comp.getSize();
double cHeight = dim.getHeight();
double cWidth = dim.getWidth();
// get the bounds of the printable area
double pHeight = format.getImageableHeight();
double pWidth = format.getImageableWidth();
double pXStart = format.getImageableX();
double pYStart = format.getImageableY();
double xRatio = pWidth/cWidth;
double yRatio = pHeight/cHeight;
Graphics2D g2 = (Graphics2D) g;
g2.translate(pXStart, pYStart);
g2.scale(xRatio, yRatio);
comp.printAll(g2);
return Printable.PAGE_EXISTS;
}
}
你與該行'如果比較引用{' – user489041
@ user489041事實上,即使'如果(preformat.equals (postformat)){'可能不起作用,因爲'PageFormat.hashCode()'沒有被覆蓋。此外,應該刪除此語句,因爲取消頁面對話框意味着用戶對當前設置感到滿意,並且應該出現打印對話框。 –
仍然無法正常工作。刪除後if(preformat!= postformat)。 –