如何找到在AWT按钮源

如何找到在AWT按钮源

本文介绍了如何找到在AWT按钮源(计算器做作业)的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

我们被要求做一个简单的图形用户界面的计算器,我用的getSource()来检测按钮,导致这就是他们教给我们。它的工作原理通过键入第一和第二值,则选择操作,它的工作。但是,我犯了一个错误,因为他们希望我们做的是这些数字也应该是按键,就像一个真正的计算器。所以我如何得到使用的getSource()每个按钮的价值?就像当我preSS键1和2是等于3香港专业教育学院做什么继承人

 进口java.awt中的*。
java.awt.event中导入*。公共类SimpleCalculator实现的ActionListener
{
    //容器
    私人帧F;
    私人面板P1,P2,P3,P4;    // 组件
    私人标签L1,L2,L3;
    私人文本字段TF1,TF2,TF3;
    私人按钮BADD,bSub,bMul,BDIV,bClear;    公共SimpleCalculator()
    {
        F =新的帧(我的第一个GUI应用程序);        P1 =新面板();
        P2 =新面板();
        P3 =新面板();
        P4 =新面板();        L1 =新标签(第一);
        L2 =新标签(二:);
        L3 =新标签(结果:);        TF1 =文本字段新(15);
        TF2 =新的TextField(15);
        TF3 =新的TextField(15);        BADD =新按钮(+);
        bSub =新按钮( - );
        bMul =新按钮(*);
        BDIV =新按钮(/);
        bClear =新按钮(C);
    }
    公共无效launchFrame()
    {
        //小组使用默认的布局管理器(FlowLayout中)
        p1.add(L1);
        p1.add(TF1);        p2.add(12);
        p2.add(TF2);        p3.add(13);
        p3.add(TF3);        p4.add(BADD);
        p4.add(bSub);
        p4.add(bMul);
        p4.add(BDIV);
        p4.add(bClear);        //改变框架的布局管理器,
        //使用网格布局(4,1)
        f.setLayout(新的GridLayout(4,1));        f.add(P1);
        f.add(P2);
        f.add(P3);
        f.add(P4);        f.pack();
        f.setVisible(真);        //注册事件处理程序
        bAdd.addActionListener(本);
        bSub.addActionListener(本);
        bMul.addActionListener(本);
        bDiv.addActionListener(本);
        bClear.addActionListener(本);        f.addWindowListener(新MyCloseButtonHandler());
    }
    //重写actionPerformed方法
    公共无效的actionPerformed(ActionEvent的AE)
    {
        对象源= ae.getSource();
        双NUM1,NUM2,结果= 0.0;        如果(tf1.getText()= NULL和放大器;!&安培;!tf2.getText()= NULL)
        {
            NUM1 = Double.parseDouble(tf1.getText());
            NUM2 = Double.parseDouble(tf2.getText());            如果(来源== BADD)
                结果= NUM​​1 + NUM2;
            否则,如果(来源== bSub)
                结果= NUM​​1 - NUM2;
            否则,如果(来源== bMul)
                结果= NUM​​1 * NUM2;
            否则,如果(来源== BDIV)
                结果= NUM​​1 / NUM2;
            否则,如果(来源== bClear)
            {
                tf1.setText(0.0);
                tf2.setText(0.0);
                tf3.setText(0.0);
            }
            其他{}
            // tf3.setText(新双(结果)的ToString());
            tf3.setText(+结果);
        }
    }
    私有类MyCloseButtonHandler WindowAdapter的扩展
    {
        公共无效的windowClosing(WindowEvent我们)
        {
            System.exit(0);
        }
    }
    公共静态无效的主要(字符串ARGS [])
    {
        SimpleCalculator SC =新SimpleCalculator();
        sc.launchFrame();
    }
}


解决方案

我会倾向于对这些数字每一个按钮,以及为操作数的每个按钮,添加文字是这样的输入/输出的文本字段。

也有一个按钮 = 。当 = 按钮被激活,调用的评估I / O文本字段的内容和结果写回吧。

例如

=

 进口java.awt中的*。
java.awt.event中导入*。
进口的javax.swing *。
进口javax.swing.border.EmptyBorder中;
进口的java.util.ArrayList;//在Java 1.6的推出脚本包
进口javax.script.ScriptEngineManager;
进口javax.script.ScriptEngine中;
进口javax.script.ScriptException;类ScriptEngineCalculator实现的ActionListener,的KeyListener {    私人JTextField的IO;
    私人的ScriptEngine引擎;
    私人的ArrayList<&的JButton GT;控制;
    私人JPanel的用户界面;    ScriptEngineCalculator(){
        initUI();
    }    公众最终无效initUI(){
        //获得对JS引擎的引用
        发动机=新ScriptEngineManager()。
                getEngineByExtension(JS);        UI =新JPanel(新的BorderLayout(2,2));
        控制=新的ArrayList<&的JButton GT;();        JPanel的文本=新JPanel(新网格布局(0,1,3,3));
        ui.add(文字,BorderLayout.PAGE_START);
        IO =新的JTextField(15);
        字体字型= io.getFont();
        字体= font.deriveFont(font.getSize()* 1.8F);
        io.setFont(字体);
        io.setHorizo​​ntalAlignment(SwingConstants.TRAILING);
        io.setFocusable(假);
        text.add(IO);        JPanel的按钮=新JPanel(新网格布局(4,4,2,2));
        ui.add(按钮,BorderLayout.CENTER);
        的String []键值{=
            7,8,9,/,
            4,5,6,*,
            1,2,3, - ,
            0,。,C,+
        };        对于(字符串的keyValue:键值){
            Add按钮(按钮,的keyValue);
        }        一个JButton等于=的新的JButton(=);
        configureButton(等于);
        ui.add(等于,BorderLayout.LINE_END);        ui.setBorder(新EmptyBorder(5,5,5,5));
    }    公共JComponent中的getUI(){
        返回UI;
    }    公共无效Add按钮(容器C,字符串文本){
        JButton的B =的新的JButton(文本);
        configureButton(二);
        c.add(二);
    }    公共无效configureButton(JButton的B){
        字体F = b.getFont();
        b.setFont(f.deriveFont(f.getSize()* 1.5F));
        b.addActionListener(本);
        b.addKeyListener(本);
        Controls.Add被(B);
    }    公共无效calculateResult(){
        尝试{
            对象result = engine.eval(io.getText());
            如果(结果== NULL){
                io.setText(输出是'空');
            }其他{
                io.setText(result.toString());
            }
        }赶上(ScriptException SE){
            io.setText(se.getMessage());
        }
    }    @覆盖
    公共无效的actionPerformed(ActionEvent的AE){
        字符串命令= ae.getActionCommand();
        如果(command.equals(C)){
            io.setText();
        }否则如果(command.equals(=)){
            calculateResult();
        }其他{
            io.setText(io.getText()+命令);
        }
    }    私人的JButton getButton(字符串文本){
        对于(JButton的按钮:控制){
            字符串s = button.getText();
            如果(text.endsWith(多个)
                    || (s.equals(=)
                    &功放;&安培; (text.equals(等于)|| text.equals(回车)))){                返回按钮;
            }
        }
        返回null;
    }    / *启动 - 因为我讨厌老鼠。 * /
    @覆盖
    公共无效键pressed(KeyEvent的KE){
    }    @覆盖
    公共无效调用keyReleased(KeyEvent的KE){
        字符串s = KeyEvent.getKeyText(ke.getKey code());
        JButton的B = getButton(S);
        如果(B!= NULL){
            b.requestFocusInWindow();
            b.doClick();
        }
    }    @覆盖
    公共无效的keyTyped(KeyEvent的KE){
    }
    / * END - 因为我讨厌老鼠。 * /    公共静态无效的主要(字串[] args){
        SwingUtilities.invokeLater(Runnable的新(){
            @覆盖
            公共无效的run(){
                ScriptEngineCalculator SC =新ScriptEngineCalculator();
                JFrame的F =新的JFrame(Calculet);
                f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
                f.setContentPane(sc.getUI());
                f.pack();
                f.setMinimumSize(f.getSize());
                f.setLocationByPlatform(真);
                f.setVisible(真);
            }
        });
    }
}

We were asked to make a simple GUI calculator, I used getSource() to detect the buttons, cause that's what they taught us. It works by typing the 1st and 2nd value then choosing the operation, it worked. But I made a mistake, because what they want us to do is that the numbers should also be buttons, just like a real calculator. so how do i get the value of each button using getSource()? like when I press button 1 and 2 is equal to 3. heres what ive done

import java.awt.*;
import java.awt.event.*;

public class SimpleCalculator implements ActionListener
{
    // containers
    private Frame f;
    private Panel p1, p2, p3, p4;

    // components
    private Label l1, l2, l3;
    private TextField tf1, tf2, tf3;
    private Button bAdd, bSub, bMul, bDiv, bClear;

    public SimpleCalculator()
    {
        f = new Frame("My First GUI App");

        p1 = new Panel();
        p2 = new Panel();
        p3 = new Panel();
        p4 = new Panel();

        l1 = new Label("First: ");
        l2 = new Label("Second: ");
        l3 = new Label("Result: ");

        tf1 = new TextField(15);
        tf2 = new TextField(15);
        tf3 = new TextField(15);

        bAdd = new Button("+");
        bSub = new Button("-");
        bMul = new Button("*");
        bDiv = new Button("/");
        bClear = new Button("C");
    }
    public void launchFrame()
    {
        // use default layout manager of the Panel (FlowLayout)
        p1.add(l1);
        p1.add(tf1);

        p2.add(l2);
        p2.add(tf2);

        p3.add(l3);
        p3.add(tf3);

        p4.add(bAdd);
        p4.add(bSub);
        p4.add(bMul);
        p4.add(bDiv);
        p4.add(bClear);

        // change the layout manager of the Frame,
        // use GridLayout(4, 1)
        f.setLayout(new GridLayout(4, 1));

        f.add(p1);
        f.add(p2);
        f.add(p3);
        f.add(p4);

        f.pack();
        f.setVisible(true);

        // register event handlers
        bAdd.addActionListener(this);
        bSub.addActionListener(this);
        bMul.addActionListener(this);
        bDiv.addActionListener(this);
        bClear.addActionListener(this);

        f.addWindowListener(new MyCloseButtonHandler());
    }
    // override the actionPerformed method
    public void actionPerformed(ActionEvent ae)
    {
        Object source = ae.getSource();
        double num1, num2, result = 0.0;

        if (tf1.getText() != null && tf2.getText() != null)
        {
            num1 = Double.parseDouble(tf1.getText());
            num2 = Double.parseDouble(tf2.getText());

            if (source == bAdd)
                result = num1 + num2;
            else if (source == bSub)
                result = num1 - num2;
            else if (source == bMul)
                result = num1 * num2;
            else if (source == bDiv)
                result = num1 / num2;
            else if (source == bClear)
            {
                tf1.setText("0.0");
                tf2.setText("0.0");
                tf3.setText("0.0");
            }
            else {}
            // tf3.setText(new Double(result).toString());
            tf3.setText("" + result);
        }
    }
    private class MyCloseButtonHandler extends WindowAdapter
    {
        public void windowClosing(WindowEvent we)
        {
            System.exit(0);
        }
    }
    public static void main(String args[])
    {
        SimpleCalculator sc = new SimpleCalculator();
        sc.launchFrame();
    }
}
解决方案

I would tend to have each button for the numbers, as well as each button for operands, add text to a text field that is the 'Input/Output'.

Also have a button =. When the = button is activated, call the javax.script.ScriptEngine to evaluate the content of the I/O text field and write the result back to it.

E.G.

=

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
import java.util.ArrayList;

// script package introduced in Java 1.6
import javax.script.ScriptEngineManager;
import javax.script.ScriptEngine;
import javax.script.ScriptException;

class ScriptEngineCalculator implements ActionListener, KeyListener {

    private JTextField io;
    private ScriptEngine engine;
    private ArrayList<JButton> controls;
    private JPanel ui;

    ScriptEngineCalculator() {
        initUI();
    }

    public final void initUI() {
        // obtain a reference to the JS engine
        engine = new ScriptEngineManager().
                getEngineByExtension("js");

        ui = new JPanel(new BorderLayout(2, 2));
        controls = new ArrayList<JButton>();

        JPanel text = new JPanel(new GridLayout(0, 1, 3, 3));
        ui.add(text, BorderLayout.PAGE_START);
        io = new JTextField(15);
        Font font = io.getFont();
        font = font.deriveFont(font.getSize() * 1.8f);
        io.setFont(font);
        io.setHorizontalAlignment(SwingConstants.TRAILING);
        io.setFocusable(false);
        text.add(io);

        JPanel buttons = new JPanel(new GridLayout(4, 4, 2, 2));
        ui.add(buttons, BorderLayout.CENTER);
        String[] keyValues = {
            "7", "8", "9", "/",
            "4", "5", "6", "*",
            "1", "2", "3", "-",
            "0", ".", "C", "+"
        };

        for (String keyValue : keyValues) {
            addButton(buttons, keyValue);
        }

        JButton equals = new JButton("=");
        configureButton(equals);
        ui.add(equals, BorderLayout.LINE_END);

        ui.setBorder(new EmptyBorder(5, 5, 5, 5));
    }

    public JComponent getUI() {
        return ui;
    }

    public void addButton(Container c, String text) {
        JButton b = new JButton(text);
        configureButton(b);
        c.add(b);
    }

    public void configureButton(JButton b) {
        Font f = b.getFont();
        b.setFont(f.deriveFont(f.getSize() * 1.5f));
        b.addActionListener(this);
        b.addKeyListener(this);
        controls.add(b);
    }

    public void calculateResult() {
        try {
            Object result = engine.eval(io.getText());
            if (result == null) {
                io.setText("Output was 'null'");
            } else {
                io.setText(result.toString());
            }
        } catch (ScriptException se) {
            io.setText(se.getMessage());
        }
    }

    @Override
    public void actionPerformed(ActionEvent ae) {
        String command = ae.getActionCommand();
        if (command.equals("C")) {
            io.setText("");
        } else if (command.equals("=")) {
            calculateResult();
        } else {
            io.setText(io.getText() + command);
        }
    }

    private JButton getButton(String text) {
        for (JButton button : controls) {
            String s = button.getText();
            if (text.endsWith(s)
                    || (s.equals("=")
                    && (text.equals("Equals") || text.equals("Enter")))) {

                return button;
            }
        }
        return null;
    }

    /* START - Because I hate mice. */
    @Override
    public void keyPressed(KeyEvent ke) {
    }

    @Override
    public void keyReleased(KeyEvent ke) {
        String s = KeyEvent.getKeyText(ke.getKeyCode());
        JButton b = getButton(s);
        if (b != null) {
            b.requestFocusInWindow();
            b.doClick();
        }
    }

    @Override
    public void keyTyped(KeyEvent ke) {
    }
    /* END - Because I hate mice. */

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                ScriptEngineCalculator sc = new ScriptEngineCalculator();
                JFrame f = new JFrame("Calculet");
                f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
                f.setContentPane(sc.getUI());
                f.pack();
                f.setMinimumSize(f.getSize());
                f.setLocationByPlatform(true);
                f.setVisible(true);
            }
        });
    }
}

这篇关于如何找到在AWT按钮源(计算器做作业)的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!

08-23 11:35