Java Swing

一. 布局管理器

• 布局器（FlowLayout）

//默认JPanel自带一个FlowLayout的流式布局器
//相当于下方的
LayoutManager layout = new FlowLayout();
root.setLayout(layout);
//默认为从左到右、从上到下的顺序

• 根据像素坐标进行布局

package FrameLearning;
import javax.swing.*;

public class test extends JFrame {

    String ID;
    public JButton cj;
    public JButton stu;
    
    public JPanel root;
    public JPanel show;
    public JPanel function;

    test(String id){
        this.ID = id;
        this.setTitle("学生页面测试");
        this.setBounds(0,100,400,200);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setLayout(null);
        this.setVisible(true);
        this.setResizable(false);
        root = new JPanel();
        root.setLayout(null);
        root.setSize(400,200);
        root.setLocation(0,0);
        this.getContentPane().add(root);
        show = new JPanel();
        show.setLocation(0,0);
        show.setSize(200,100);
        show.setLayout(null);


        cj = new JButton("成绩查询");
        cj.setBounds(0,0,80,40);
        show.add(cj);
        root.add(show);

        function = new JPanel();
        function.setLayout(null);
        function.setLocation(200,0);
        function.setSize(200,100);

        stu = new JButton("欢迎"+this.ID);
        stu.setBounds(0,0,180,40);
        function.add(stu);


        root.add(function);
    }

}
class showFrame{
    public static void main(String []args)
    {
        test myframe = new test("19123048");
    }
}

被一个容器如父Frame、根Panel所包含时，

子Panel使用setLocation方法的x,y从根Panel的左上坐标来表示（即根的左上坐标为0,0），而不是由整个页面的左上坐标决定

同理子Panel中的组件如JButton、JTextField对象也是根据子Panel的左上坐标来表示的。

二. JTable

String[][] data = {{"Kundan Kumar Jha","4031","CSE"},{"Anand Jha","6014","IT"}};
String[] columnNames = {"Name","Roll Number","Department"};
//the table is constructed using these data and columnNames
JTable table = new JTable(data, columnNames);

JScrollPane scrollPane = new JScrollPane(table);
//创建滑动窗格，并把Jtable对象添加进去
table.setFillsViewportHeight(true);
//

• 使用BorderLayout布局

package FrameLearning;

import javax.swing.*;
import java.awt.*;

public class myframe extends JFrame {
    myframe(){

    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    this.setSize(650,600);
    this.setLayout(new BorderLayout(5,20));
    ((JPanel)this.getContentPane()).setBorder(BorderFactory.createEmptyBorder(5,10,10,10));
    JPanel jPanelNorth = new JPanel();
    jPanelNorth.setPreferredSize(new Dimension(630,40));
    jPanelNorth.setLayout(new FlowLayout(FlowLayout.RIGHT,10,0));
    //流式布局
    this.add(jPanelNorth,"North");

    JLabel jLabelMsg = new JLabel();
    jLabelMsg.setPreferredSize(new Dimension(60,40));
    Font font = new Font("Dialog",1,12);
    Font labelFont = new Font("Dialog",1,14);
    jLabelMsg.setFont(labelFont);
    jLabelMsg.setText("欢迎您：");
    jPanelNorth.add(jLabelMsg);

    JLabel jLabelStu = new JLabel();
    jLabelStu.setPreferredSize(new Dimension(70,40));
    jLabelStu.setText("19123048");
    jLabelStu.setFont(labelFont);
    jPanelNorth.add(jLabelStu);

    JButton jButtonExit = new JButton("退出");
    jButtonExit.setPreferredSize(new Dimension(70,35));
    jButtonExit.setFont(font);
    jPanelNorth.add(jButtonExit);

    JPanel jPanelFunction = new JPanel();
    jPanelFunction.setPreferredSize(new Dimension(150,540));
    jPanelFunction.setLayout(new FlowLayout(FlowLayout.LEFT,10,10));
    JButton jButtonQuery = new JButton("成绩查询");
    jButtonQuery.setPreferredSize(new Dimension(100,40));

    jPanelFunction.add(jButtonQuery);
    this.add(jPanelFunction,"Center");

    String[] col_name = {"course_order", "course_name"};
    Object[][] tableData = new Object[0][0];
    JTable table = new JTable(tableData,col_name);
    JScrollPane scrollPane = new JScrollPane(table);
    scrollPane.setPreferredSize(new Dimension(450,540));
    this.pack();

    this.add(scrollPane,"East");

     this.setVisible(true);

    }
}
class runframe{
    public static void main(String []args){
        myframe myframe = new myframe();
    }
}

package cjdemo;

import javax.swing.*;
import java.awt.*;
import java.sql.SQLException;

import jdbctest.DBConnector;
import jdbctest.CustomException;

/**
 * @description : 显示学生界面，包含成绩查询功能
 * @Content : 组件内容：1.Jtable类型的成绩表格cjtable
 *                    2.JPanel类型的学生信息面板stuPanel
 *                    2.JPanel类型的功能面板panel_function
 *                    3.JPanel类型的成绩表格显示面板panel_show
 *
 */
public class stuFrame extends JFrame {
    int id;
    JScrollPane scrollPane;
    JPanel panel_show;

    /**
     * @param ID: 根据学生ID来创建学生页面
     * @throws SQLException
     * @throws CustomException
     */
    public  stuFrame(int ID) throws SQLException, CustomException {
        id = ID;

        this.setResizable(false);
        // 调用setBounds方法调整页面的左上角坐标以及页面的大小
//        this.setBounds(100, 100, 1000, 800);
        this.setTitle(this.id+"学生成绩管理页面");
        // 将右上角的[x]与退出程序相关联
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setVisible(true);

        this.setSize(700,600);
        this.setLocation(100,100);
        this.setLayout(new BorderLayout(5,20));
        ((JPanel)this.getContentPane()).setBorder(BorderFactory.createEmptyBorder(5,10,10,10));

        /**
         * @function: 创建显示欢迎学生的窗格。
         */
        JPanel  stuPanel = new JPanel();
        stuPanel.setPreferredSize(new Dimension(700,80));
        stuPanel.setLayout(new FlowLayout(FlowLayout.RIGHT,10,5));
        this.add(stuPanel,"North");

        JLabel stuInfo = new JLabel();
        stuInfo.setPreferredSize(new Dimension(120,60));
        Font font = new Font("Dialog",1,12);
        Font labelFont = new Font("Dialog",1,14);
        stuInfo.setText("欢迎您："+this.id);
        stuInfo.setFont(labelFont);
        stuPanel.add(stuInfo);

        JButton exitButton = new JButton("安全退出");
        exitButton.setPreferredSize(new Dimension(100,60));
        exitButton.setFont(font);
        stuPanel.add(exitButton);


        int[] int_args = new int[2];
        String[] str_args = new String[0];
        int_args[0] = 3002001;
        int_args[1] = 2002001;
        DBConnector conn = new DBConnector();
        Object[][] tableData = new Object[0][0];
        try {
            tableData = conn.search("课程成绩查询", int_args, str_args);
        } catch (CustomException e) {
            System.out.println(e.getMessage());
            return;
        }
//        System.out.println(tableData.length);
        String[] col_name = {"course_order", "course_name", "teacher_id", "course_time", "course_credit", "score"};

        /**
         * @function： 创建成绩显示表格cjtable
         */
        JTable cjtable = new JTable(tableData, col_name);
//        cjtable.setBounds(0,0,700,300);
        cjtable.setSize(700,300);
//        cjtable.setPreferredSize(new Dimension(700,300));
        // 将表格设置为不可编辑
        cjtable.setEnabled(false);

        /**
         *  @function: 创建成绩显示面板,显示学生成绩
         */
//        scrollPane = new JScrollPane(cjtable);
//        scrollPane.setPreferredSize(new Dimension(800,700));
//        scrollPane.setVisible(true);
//        this.add(scrollPane,"East");
        panel_show = new JPanel();
        panel_show.setLayout(new FlowLayout(FlowLayout.RIGHT,0,0));
        panel_show.setPreferredSize(new Dimension(500,700));
        this.add(panel_show,"East");
        panel_show.add(new JScrollPane(cjtable));
        panel_show.setVisible(false);


        /**
         *  @function: 创建功能栏面板panel_function,包含成绩查询按钮button组件
         */
        JPanel panel_function = new JPanel();
        panel_function.setLayout(new FlowLayout(FlowLayout.LEFT,5,5));
        panel_function.setPreferredSize(new Dimension(100,700));
        this.add(panel_function,"Center");


        JButton button = new JButton("成绩查询");
        button.setFont(font);
        button.setPreferredSize(new Dimension(100,60));

        /**
         * @function: 为【成绩查询】按钮创建监听器，点击后成绩显示窗格状态改为【显示】
         * 函数参数采用lambda表达式
         */
        button.addActionListener((e) -> {
            panel_show.setVisible(true);
        });
        //将【成绩查询】按钮组件添加到功能栏面板中
        panel_function.add(button);

    }

}