Question

所以我只是在课堂上用Java启动GUI，我遇到了一个奇怪的问题。对于个人实践，我想制作一种简单的“电子表格”应用程序。现在我只是想让它显示列名。它就是这样，但就像我的JOptionPane.showInputDialog弹出框的图像一样。

以下是我的三个课程：

JPanel.java：

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;

import javax.swing.JOptionPane;
import javax.swing.JPanel;

public class Panel extends JPanel{

    private Spreadsheet SprdSht;
    public Panel(Spreadsheet sprdSht){
        SprdSht = sprdSht;
    }

    public Panel(){
         SprdSht = new Spreadsheet(0,0);

    }

    public void paintComponent(Graphics thing){

        super.paintComponent(thing);    
        int width = getWidth();
        int height = getHeight();

        String temp[] = new String[100];

        for(int x = 0; x<SprdSht.getCols(); x++){
            temp[x] = JOptionPane.showInputDialog("Column " + (x+1) + " name?");
        }

        for(int x = 0; x<SprdSht.getCols(); x++){

            thing.drawString(temp[x], x*50+5, 15);      
        }    
    }
}

TestSpreadsheet.java：

import javax.swing.JFrame;
import javax.swing.JOptionPane;

public class TestSpreadsheet {
    public static void main(String args[]){
        try{
            String numColumnsStr = JOptionPane.showInputDialog("Number of columns?");
            int  numColumns = Integer.parseInt(numColumnsStr);
            String numRowsStr = JOptionPane.showInputDialog("Number of rows?");
            int  numRows = Integer.parseInt(numRowsStr);
            Spreadsheet sprdSht = new Spreadsheet(numColumns,numRows);


            Panel tempGradePanel = new Panel(sprdSht);      
            JFrame tempFrame = new JFrame();
            tempFrame.setDefaultCloseOperation(3);
            tempFrame.add(tempGradePanel);
            tempFrame.setSize(500, 500);
            tempFrame.setVisible(true);     
       }    
        catch (Exception exc){
          JOptionPane.showMessageDialog(null, "Bad response, closing program.");
        }       
    }           
}

Spreadsheet.java：

public class Spreadsheet {

    private int Columns;
    private int Rows;

    public Spreadsheet(int cols, int rows){
        Columns=cols;
        Rows=rows;      
    }

    public int getCols(){
        return Columns;
    }
    public int getRows(){
        return Rows;
    }   
}

我输入#columns后输入2，#rows输入1，第1列名称输入“column1”，第2列名称输入“column2”： http://i.stack.imgur.com/ykQrz.png

showInputDialog框的图像卡在JFrame上

0 个答案: