我正在使用 Java 打印 API，并且已经从这个 oracle 页面获得了打印多页帐单发票文档的代码。
以及此页面中的示例代码
现在，正如您所知，大多数发票都有从页面中心顶部开始的项目计费详细信息，这是动态值，有时详细信息会被推送到下一页。
我用上面的代码摆弄和修改，下面是我的工作代码。
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.awt.print.*;
public class PaginationExample implements Printable, ActionListener {
int[] pageBreaks1, pageBreaks2; // array of page break line positions.
/* Synthesize some sample lines of text */
String[][] textLines;
private void initTextLines() {
if (textLines == null) {
int numLines=300;
textLines = new String[numLines][3];
textLines = new String[numLines][4];
for (int i=0;i<numLines;i++) {
textLines[i][0]= "1. This is line number " + i;
textLines[i][1]= "2. This is line number " + i;
textLines[i][2]= "3. This is line number " + i;
}
}
}
public int print(Graphics g, PageFormat pf, int pageIndex) throws PrinterException {
Font font = new Font("Serif", Font.PLAIN, 10);
FontMetrics metrics = g.getFontMetrics(font);
int lineHeight = metrics.getHeight();
int linesPerPage1 = (int)(550/lineHeight);
int linesPerPage2 = (int)(750/lineHeight);
initTextLines();
if (pageBreaks1 == null) {
int numBreaks1 = (textLines.length-1)/linesPerPage1;
pageBreaks1 = new int[numBreaks1];
for (int b1=0; b1<numBreaks1; b1++) {
pageBreaks1[b1] = (b1+1)*linesPerPage1;
}
}
if (pageBreaks2 == null) {
int numBreaks2 = (textLines.length-1)/linesPerPage2;
pageBreaks2 = new int[numBreaks2];
for (int b2=0; b2<numBreaks2; b2++) {
pageBreaks2[b2] = (b2+1)*linesPerPage2;
}
}
if (pageIndex > pageBreaks1.length) {
return NO_SUCH_PAGE;
}
if (pageIndex > pageBreaks2.length) {
return NO_SUCH_PAGE;
}
/* User (0,0) is typically outside the imageable area, so we must
* translate by the X and Y values in the PageFormat to avoid clipping
* Since we are drawing text we
*/
Graphics2D g2d = (Graphics2D)g;
g2d.translate(pf.getImageableX(), pf.getImageableY());
/* Draw each line that is on this page.
* Increment 'y' position by lineHeight for each line.
*/
int y = (pageIndex == 0) ? 200 : 30;
int start = (pageIndex == 0) ? ((pageIndex == 0) ? 0 : pageBreaks1[pageIndex-1])
: ((pageIndex == 0) ? 0 : pageBreaks2[pageIndex-1]);
int end = (pageIndex == 0) ? ((pageIndex == pageBreaks1.length) ? textLines.length : pageBreaks1[pageIndex])
: ((pageIndex == pageBreaks2.length) ? textLines.length : pageBreaks2[pageIndex]);
for (int line=start; line<end; line++) {
y += lineHeight;
g.drawString(textLines[line][0], 10, y);
g.drawString(textLines[line][1], 100, y);
g.drawString(textLines[line][2], 200, y);
g.drawString(textLines[line][3], 300, y);
}
return PAGE_EXISTS;
}
public void actionPerformed(ActionEvent e) {
PrinterJob job = PrinterJob.getPrinterJob();
job.setPrintable(this);
boolean ok = job.printDialog();
if (ok) {
try {
job.print();
} catch (PrinterException ex) {
/* The job did not successfully complete */
}
}
}
public static void main(String args[]) {
try {
String cn = UIManager.getSystemLookAndFeelClassName();
UIManager.setLookAndFeel(cn); // Use the native L&F
} catch (Exception cnf) {
}
JFrame f = new JFrame("Printing Pagination Example");
f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {System.exit(0);}
});
JButton printButton = new JButton("Print Pages");
printButton.addActionListener(new PaginationExample());
f.add("Center", printButton);
f.pack();
f.setVisible(true);
}
}
现在我得到的问题是下图中的这个。
发生的事情是代码错误地进行迭代，因为并跳转了数组中的一些元素，并且此错误仅发生在第一页。
我相信我在上面发布的代码中的问题就在这里。
int y = (pageIndex == 0) ? 200 : 30;
int start = (pageIndex == 0) ? ((pageIndex == 0) ? 0 : pageBreaks1[pageIndex-1])
: ((pageIndex == 0) ? 0 : pageBreaks2[pageIndex-1]);
int end = (pageIndex == 0) ? ((pageIndex == pageBreaks1.length) ? textLines.length : pageBreaks1[pageIndex])
: ((pageIndex == pageBreaks2.length) ? textLines.length : pageBreaks2[pageIndex]);
for (int line=start; line<end; line++) {
y += lineHeight;
g.drawString(textLines[line][0], 10, y);
g.drawString(textLines[line][1], 100, y);
g.drawString(textLines[line][2], 200, y);
g.drawString(textLines[line][3], 300, y);
}
它尝试修复迭代，但它不起作用。如果可能的话，请指导我这里哪里出错了。
谢谢 ：）。