如何在此表上执行添加操作？ [英] How addition operation can be performed on this table?
问题描述
import javax.swing.*;
import javax.swing.event.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JComponent;
import javax.swing.SwingUtilities;
import net.java.dev.designgridlayout.DesignGridLayout;
import java.io.*;
import net.java.dev.designgridlayout.Tag;
import javax.swing.JButton;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableModel;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.*;
import java.sql.*;
import javax.swing.table.TableColumn;
class table1 {
JFrame JF;
Container C;
JPanel JP;
JLabel creditLabel;
JComboBox credit;
String[] Credit = { "Vasan Phalke", "Pansare", "Anil Kg", "Suresh",
"Total Credit", "" };
String[] Names = { "Name", "Qty", "Rate/ Kg", "Total Amt." };
JTable table;
DefaultTableModel model;
JScrollPane scrollPane;
public table1() {
JF = new JFrame();
JP = new JPanel();
C = JF.getContentPane();
C.setLayout(new BorderLayout());
JF.pack();
JF.setLocationRelativeTo(null);
JF.setVisible(true);
DesignGridLayout layout = new DesignGridLayout(JP);
creditLabel = new JLabel("Credit");
credit = new JComboBox<String>(Credit);
model = new DefaultTableModel(Names, 6) {
@Override
public Class<?> getColumnClass(int columnIndex) {
switch (columnIndex) {
case 0:
return String.class;
case 1:
return Integer.class;
case 2:
case 3:
return Double.class;
}
return super.getColumnClass(columnIndex);
}
public Object getValueAt(int row, int column) {
if (column == 3) {
Integer i = (Integer) getValueAt(row, 1);
Double d = (Double) getValueAt(row, 2);
if (i != null && d != null) {
return i * d;
} else {
return 0 * 0;
}
}
return super.getValueAt(row, column);
}
public boolean isCellEditable(int arg0, int arg1) {
return true;
}
public void setValueAt(Object aValue, int row, int column) {
super.setValueAt(aValue, row, column);
fireTableCellUpdated(row, 3);
}
};
table = new JTable(model);
{
TableColumn nameColumn = table.getColumnModel().getColumn(0);
nameColumn.setCellEditor(new DefaultCellEditor(credit));
}
scrollPane = new JScrollPane(table);
layout.row().grid(creditLabel);
layout.emptyRow();
layout.row().grid().add(scrollPane);
C.add(JP);
}
public static void main(String args[]) {
new table1();
}
}
我想要Total Amt的总和。列出现在单元格上（5,4）。我尝试了一些代码，但是失败了，请在下面添加显示附加图像的代码。从过去的5个小时开始，我被困在这桌子里。在此先感谢。
I want the total of Total Amt. column to appear on the cell (5,4). I tried some code, which fails, the code which shows the image attached is added below, please. I am stuck at this table thing from past 5 hrs. Thanks in advance.
推荐答案
您的示例的简化变体，其中包含此方法如下所示。请注意以下几点：
A simplified variation of your example that incorporates this approach is shown below. Note several important points:
-
虽然
JTable是不电子表格， 可以动态更新单元格，以帮助理解。使用TableModelListener更新相关的视图组件。
While a
JTableis not a spreadsheet, it is possible to update cells dynamically as an aid to understanding. Use aTableModelListenerto update related view components.
TableModel 应该为 fireTableDataChanged（）用于在这个固定尺寸的小型号上使用。
The TableModel should fire events for the least number of cells possible; fireTableDataChanged() is used for expedience on this small, fixed-size model.
始终 pack（）封闭的窗口和make setVisible（） 最后。
Always pack() the enclosing Window and make setVisible() last.
Swing GUI objects should be constructed and manipulated only on the event dispatch thread.
使用通用编码约定。
代码经测试：
import java.awt.EventQueue;
import javax.swing.*;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableColumn;
public class Table1 {
JFrame frame;
JComboBox credit;
String[] rowNames = {
"Vasan Phalke", "Pansare", "Anil Kg", "Suresh", "Total Credit", ""};
String[] colNames = {"Name", "Qty", "Rate/ Kg", "Total Amt."};
JTable table;
DefaultTableModel model;
JScrollPane scrollPane;
public Table1() {
frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
credit = new JComboBox<>(rowNames);
model = new DefaultTableModel(colNames, 6) {
@Override
public Class<?> getColumnClass(int columnIndex) {
switch (columnIndex) {
case 0:
return String.class;
case 1:
return Integer.class;
case 2:
return Double.class;
case 3:
return Double.class;
}
return super.getColumnClass(columnIndex);
}
@Override
public Object getValueAt(int row, int col) {
if (col == 3 & row == 5) {
double sum = 0;
for (int i = 0; i < 5; i++) {
sum += ((Double) getValueAt(i, 3)).doubleValue();
}
return sum;
}
if (col == 3 & row != 5) {
Integer i = (Integer) getValueAt(row, 1);
Double d = (Double) getValueAt(row, 2);
if (i != null && d != null) {
return i * d;
} else {
return 0d;
}
}
return super.getValueAt(row, col);
}
@Override
public void setValueAt(Object aValue, int row, int col) {
super.setValueAt(aValue, row, col);
fireTableDataChanged();
}
@Override
public boolean isCellEditable(int row, int col) {
return col != 3;
}
};
table = new JTable(model);
TableColumn nameColumn = table.getColumnModel().getColumn(0);
nameColumn.setCellEditor(new DefaultCellEditor(credit));
scrollPane = new JScrollPane(table);
frame.add(new JScrollPane(table));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String args[]) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
new Table1();
}
});
}
}
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