實驗內容：

1.計算圓面積，

2.四則運算器，

實驗步驟：

1.計算圓面積，在第一個文本框中輸入圓的半徑，然后計算此圓面積的值，并將此值放入到第二個文本框中，

源代碼：

package homework.實驗11_圖形用戶界面;

import java.awt.Button;
import java.awt.Frame;
import java.awt.Label;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;


public class Circle extends Frame implements ActionListener {
    private static final long serialVersionUID = 1L;
    static TextField tf1 = new TextField();
    static TextField tf2 = new TextField();
    static Label lab1 = new Label("radius");
    static Button bt = new Button("area");

    public static void main(String[] args){
        Circle c = new Circle();
        c.setTitle("求面積");
        c.setLayout(null);
        c.setVisible(true);
        c.setSize(400,400);
        c.add(lab1);
        c.add(bt);
        c.add(tf1);
        c.add(tf2);
        lab1.setBounds(40, 90, 110, 35);
        tf1.setBounds(170, 90, 110, 35);
        bt.setBounds(40, 180, 110, 35);
        tf2.setBounds(170, 180, 110, 35);
        bt.addActionListener(c); //注冊事件監聽器
        c.addWindowListener(new WindowAdapter(){
            public void windowClosing(WindowEvent e){
                System.exit(0);
            }
        });  //添加一個監聽器，重寫windowClosing方法，才能關閉視窗

    }
    public void actionPerformed(ActionEvent e){
        int r = Integer.parseInt(tf1.getText());
        float s = (float) ((float)r*r*Math.PI);
        String str = String.valueOf(s);
        tf2.setText(str);

    }

}

運行結果截圖：

2.在表單上創建3個文本框，兩個用于輸入運算物件，另一個用于存放計算結果，下拉串列框選擇四則運算子號，

源代碼：

package homework.實驗11_圖形用戶界面;

import java.awt.Button;
import java.awt.Choice;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;

import javax.swing.*;


public class calculated extends JFrame {
    private static final long serialVersionUID = 1L;
    JTextField num1 = new JTextField();
    JTextField num2 = new JTextField();
    JTextField total = new JTextField();
    static Choice ch = new Choice();

    public static void main(String[] args){
        calculated c = new calculated();
        c.setTitle("計算器");
        c.operation();
        c.setBackground(Color.cyan);
        c.setSize(400,300);
        c.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  //關閉視窗
    }

    public void operation(){
        ch.add("+");
        ch.add("-");
        ch.add("*");
        ch.add("/");
        num1.setColumns(5);  //設定此文本框的列數
        num2.setColumns(5);
        total.setColumns(5);
        setLayout(new FlowLayout());  //采用流式布局管理器
        Button bt = new Button("=");
        bt.setBackground(Color.cyan);
        bt.addActionListener(new MyListener(this));  //bt注冊事件監聽器
        ch.addItemListener(new ChoiceHandler());   //ch注冊事件監聽器
        add(num1);  //將文本框加入到表單
        add(ch);
        add(num2);
        add(bt);
        add(total);
        setVisible(true); //設定表單可見
    }

}
    class MyListener implements ActionListener {
    private calculated mulp;
    public MyListener(calculated mulp){
        this.mulp = mulp;
    }
        @Override
        public void actionPerformed(ActionEvent e) {
            try {
                String s1 = mulp.num1.getText();
                String s2 = mulp.num1.getText();
                int i1 = Integer.parseInt(s1);
                int i2 = Integer.parseInt(s2);
                String itm;
                itm = ChoiceHandler.itml;
                if(itm.equals("+")){
                    mulp.total.setText(String.valueOf(i1+i2));
                }else if(itm.equals("-")){
                    mulp.total.setText(String.valueOf(i1-i2));
                }else if(itm.equals("*")){
                    mulp.total.setText(String.valueOf(i1*i2));
                }else if(itm.equals("/")){
                    mulp.total.setText(String.valueOf(i1/i2));
                }
            }catch(Exception e2){
                JOptionPane.showMessageDialog(null,"除數不能為0");
            }

        }
    }


class ChoiceHandler implements ItemListener {
    static String itml;
    @Override
    public void itemStateChanged(ItemEvent e) {
        itml = calculated.ch.getSelectedItem();
    }
}

運行結果截圖：

實驗小結

swing：在awt的基礎上建立的一套圖形界面系統，屬于Javax擴展包下，其中提供了更多的組件，而且完全由Java實作增強了移植性，屬輕量級控制元件，

GUI API包含的類可以分為三個組:組件類(component class),容器類(container class),輔助類(helper class).它們的體系結構如下: