Question

我是java的新手，所以请帮我解决我的问题。这是我打印收据账单的代码

public  class BillPrintable implements Printable{

public int print(Graphics graphics,PageFormat pageformat,int pageIndex)throws PrinterException
    {
        int result = NO_SUCH_PAGE;
        if(pageIndex == 0)
        {
            Graphics2D g2d= (Graphics2D) graphics;
            double width = pageformat.getImageableWidth();
            g2d.translate((int) pageformat.getImageableX(), (int) pageformat.getImageableY());
            FontMetrics metrics=g2d.getFontMetrics(new Font("Arial",Font.BOLD,7));
            int idLength=metrics.stringWidth("000");
            int amtLength=metrics.stringWidth("000000");
            int qtyLength=metrics.stringWidth("000000");
            int priceLength=metrics.stringWidth("00000");
            int prodLength=(int)width-idLength-amtLength-priceLength-17;

            int productPosition = 0;
            int discountPosition=prodLength+0;
            int pricePosition =discountPosition+idLength + 10;
            int qtyPosition = pricePosition + priceLength + 4;
            int amtPosition = qtyPosition + qtyLength;
            try {
                int y=20;
                int yShift = 10;
                int headerRectHeight = 15;
                int headerRectHeighta = 40;
                g2d.setFont(new Font("Monospaced",Font.PLAIN,9));
                g2d.drawString("............................", 12, y);y+=yShift;
                g2d.drawString("  Restaurant Bill Reciept   ", 12, y);y+=yShift;
                g2d.drawString("----------------------------", 12, y);y+=headerRectHeighta;


                g2d.drawString("......................................", 10, y);y+=yShift;


                g2d.drawString("......................................", 10, y);;y+=yShift;

                g2d.drawString("          Free Home Delivery          ", 10, y);;y+=yShift;
                g2d.drawString("             9895776277               ", 10, y);;y+=yShift;
                g2d.drawString("......................................", 10, y);;y+=yShift;
                g2d.drawString("      Thanks To Visit Our Restaurant  ", 10, y);;y+=yShift;
                g2d.drawString("......................................", 10, y);;y+=yShift;

            }
            catch(Exception r)
            {
                r.printStackTrace();
            }
            result = PAGE_EXISTS;
        }
        return result;
    }


}

这里我得到的错误就像这个The type bill.BillPrintable must implement the inherited abstract method Printable.print(Graphics, PageFormat, int)。不知道问题是如何产生的以及如何解决问题。请帮助我提前解决这是我导入的语句。请看看

import java.awt.Font;
import java.awt.Graphics2D;
import javafx.print.Paper;
import com.sun.prism.Graphics;
import java.awt.print.PageFormat;
import java.awt.print.Printable;
import java.awt.print.PrinterException;
import java.awt.print.PrinterJob;
import java.text.*;
import java.awt.print.*;
import java.awt.print.PageFormat.*;
import java.awt.print.Paper.*;
import javax.swing.UIManager;
import java.awt.FontMetrics;

Answer 1

您从错误的包中导入类Graphics：

import com.sun.prism.Graphics

必须是

import java.awt.Graphics

以下导入也是无关紧要的：

import java.text.*;
import java.awt.print.*;
import java.awt.print.PageFormat.*;
import java.awt.print.Paper.*;

注意：您不应该直接使用com.sun课程

Answer 2

错误是覆盖从父类继承的方法print(Graphics, PageFormat, int)。参数应该与父方法相同，或者java将它声明为新方法，而不是覆盖方法。此方法也是静态的，因此您可以调用此方法，而无需实例化类。

Answer 3

来自Wrong包的图形
请试试这个

import java.awt.Graphics

使用工具时java获取错误

3 个答案: