图形用户界面设计表格组件示例

程序运行结果截图：

程序清单如下：

import javax.swing.*;

import java.awt.*;

import java.awt.event.*;

public class Example10_16

{

public static void main(String arts [])

{

Win win = new Win();

}

}

class Win extends JFrame implements ActionListener

{

JTable table;

Object a[][];

Object name[] = {"商品名称","单价","销售量","销售额"};

JButton computerRows,computerColums;

JTextField inputRowsNumber;

int initRows = 1;

JPanel pSouth,pNorth;

int count = 0,rowsNumber = 0;

Win()

{

computerRows = new JButton("每件商品销售额");

computerColums = new JButton("总销售额");

inputRowsNumber = new JTextField(10);

computerRows.addActionListener(this);

computerColums.addActionListener(this);

inputRowsNumber.addActionListener(this);

pSouth = new JPanel();

pNorth = new JPanel();

pNorth.add(new JLabel("输入表格行数，回车确认"));

pNorth.add(inputRowsNumber);

pSouth.add(computerRows);

pSouth.add(computerColums);

add(pSouth,BorderLayout.SOUTH);

add(pNorth,BorderLayout.NORTH);

add(new JScrollPane(table),BorderLayout.CENTER);

setBounds(100,100,370,250);

setVisible(true);

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

public void actionPerformed(ActionEvent e)

{

if(e.getSource() == inputRowsNumber)

{

count = 0;

initRows = Integer.parseInt(inputRowsNumber.getText());

a = new Object[initRows][4];

for(int i = 0;i < initRows;i++)

{

for(int j = 0;j < 4;j++)

{

a[i][j] = 0;

}

}

table = new JTable(a,name);

table.setRowHeight(20);

getContentPane().removeAll();

add(new JScrollPane(table),BorderLayout.CENTER);

add(pSouth,BorderLayout.SOUTH);

add(pNorth,BorderLayout.NORTH);

validate();

}

else if(e.getSource() == computerRows)

{

int rows = table.getRowCount(); //获取现有表格行数

for(int i = 0;i < rows;i++)

{

double sum = 1;

boolean boo = true;

for(int j = 1;j <= 2;j++)

{

try

{

sum = sum * Double.parseDouble(a[i][j].toString());

}

catch(Exception ee)

{

boo = false;

table.repaint(); //表格更新显示

}

if(boo == true)

{

a[i][3] = "" + sum; //修改数组中的数据

table.repaint();

}

}

}

}

else if(e.getSource() == computerColums)

{

if(count == 0)

{

rowsNumber = table.getRowCount(); //获取表格的目前的行数

count++;

}

else

{

rowsNumber = table.getRowCount(); //获取表格的目前的行数

rowsNumber = rowsNumber - 1; //不要最后一行

}

double totalSum = 0;

for(int j = 0;j < rowsNumber;j++)

{

totalSum = totalSum + Double.parseDouble(a[j][3].toString());

}

Object b[][] = new Object[rowsNumber + 1][4]; //比数组a多一行的数组

for(int i = 0;i < rowsNumber;i++)

{ //将数组a的数据复制到数组b中for(int j = 0;j < 4;j++)

{

b[i][j] = a[i][j];

}

}

b[rowsNumber][0] = "一共有" + rowsNumber + "件商品";

b[rowsNumber][3] = "总销售额" + totalSum;

a = b; //重新初始化a

table = new JTable(a,name);

getContentPane().removeAll();

add(new JScrollPane(table),BorderLayout.CENTER);

add(pSouth,BorderLayout.SOUTH);

add(pNorth,BorderLayout.NORTH);

validate();

}

}

}