GUI编程网格布局实现简单计算器

约定不等于承诺〃 2021-10-29 22:34 374阅读 0赞

1.效果图：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyMzIxMzM2_size_16_color_FFFFFF_t_70]  
功能基本都能实现，只是集中方法的特殊情况没有实现，像/0.  
2.代码实现：

package note;
    
    import java.awt.BorderLayout;
    import java.awt.GridLayout;
    import java.awt.TextField;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    
    import javax.swing.JButton;
    import javax.swing.JFrame;
    import javax.swing.JPanel;
    
    public class Calculate {
    	TextField tf = new TextField(40);       
        StringBuffer s1 = new StringBuffer();   
        StringBuffer s2 = new StringBuffer();   
        static String flag = new String();      
        boolean start = true;   
     
        public void init(){
            //主界面
        	
            JFrame f = new JFrame("计算器");
            f.setSize(800, 800);
            JPanel p1 = new JPanel();
            p1.add(tf);
            f.add(p1,BorderLayout.NORTH);
            JPanel p2 = new JPanel();
            p2.setLayout(new GridLayout(1,3));
            //动作监听器
            ActionListener listen =new ActionListener() {
     
                public void actionPerformed(ActionEvent arg0) {
     
                    //输入数字0~9
                    if(arg0.getActionCommand()=="0"){
     
                        if(!s1.toString().equals(new String())){
                            if(!start){
                                //s1清零，保证可以重新输入数字
                                s1.delete(0, s1.length());
                            }
                            start = true;
                            tf.setText(s1.append("0").toString());
                        }   
                    }
                    if(arg0.getActionCommand()=="1"){
                        if(!start){
                            s1.delete(0, s1.length());
                        }
                        start = true;
                        tf.setText(s1.append("1").toString());
                    }
                    if(arg0.getActionCommand()=="2"){
                        if(!start){
                            s1.delete(0, s1.length());
                        }
                        start = true;
                        tf.setText(s1.append("2").toString());
                    }
                    if(arg0.getActionCommand()=="3"){
                        if(!start){
                            s1.delete(0, s1.length());
                        }
                        start = true;
                        tf.setText(s1.append("3").toString());
                    }
                    if(arg0.getActionCommand()=="4"){
                        if(!start){
                            s1.delete(0, s1.length());
                        }
                        start = true;
                        tf.setText(s1.append("4").toString());
                    }
                    if(arg0.getActionCommand()=="5"){
                        if(!start){
                            s1.delete(0, s1.length());
                        }
                        start = true;
                        tf.setText(s1.append("5").toString());
                    }
                    if(arg0.getActionCommand()=="6"){
                        if(!start){
                            s1.delete(0, s1.length());
                        }
                        start = true;
                        tf.setText(s1.append("6").toString());
                    }
                    if(arg0.getActionCommand()=="7"){
                        if(!start){
                            s1.delete(0, s1.length());
                        }
                        start = true;
                        tf.setText(s1.append("7").toString());
                    }
                    if(arg0.getActionCommand()=="8"){
                        if(!start){
                            s1.delete(0, s1.length());
                        }
                        start = true;
                        tf.setText(s1.append("8").toString());
                    }
                    if(arg0.getActionCommand()=="9"){
                        if(!start){
                            s1.delete(0, s1.length());
                        }
                        start = true;
                        tf.setText(s1.append("9").toString());
                    }
                    //输入小数点
                    if(arg0.getActionCommand()=="."){
                        if(!start){
                            s1.delete(0, s1.length());
                        }
                        start=true;
                        if(s1.toString().equals(new String()))
                            tf.setText(s1.append("0.").toString());
                        else if(s1.length()==1&&s1.charAt(0)=='-')
                            tf.setText(s1.append("0.").toString());
                        else
                            tf.setText(s1.append(".").toString());
                    }
                    //输入负号
                    if(arg0.getActionCommand()=="+/-"){
                        if(!start){
                            s1.delete(0, s1.length());
                        }
                        start = true;
                        if(s1.toString().equals(new String()))
                            tf.setText(s1.append('-').toString());
                    }
                    //退格Backspace
                    if(arg0.getActionCommand()=="Backspace"){
                        start = true;
                        if(s1.length()!=0){
                            //删除最后输入的一位
                            s1.deleteCharAt(s1.length()-1);
                            tf.setText(s1.toString());
                        }
                    }
                    //归零CE
                    if(arg0.getActionCommand()=="CE"){
                        //清空所有，start标记设为true
                        start = true;
                        s1.delete(0, s1.length());
                        s2.delete(0, s2.length());
                        tf.setText(s1.toString());
                    }
                    //清除C
                    if(arg0.getActionCommand()=="C"){
                        //清空当前输入，即s1清零
                        start = true;
                        s1.delete(0, s1.length());
                        tf.setText(s1.toString());
                    }
                    //加号
                    if(arg0.getActionCommand()=="+"){
                        start = true;
                        flag="+";
                        //s2接收s1的值
                        s2.append(String.valueOf(s1.toString()));
                        //s1清零，重新接收下一个数据
                        s1.delete(0, s1.length());
                        tf.setText(s1.toString());
                    }
                    //减号
                    if(arg0.getActionCommand()=="-"){
                        start = true;
                        flag="-";
                        s2.append(String.valueOf(s1.toString()));
                        s1.delete(0, s1.length());
                        tf.setText(s1.toString());
                    }
                    //乘号
                    if(arg0.getActionCommand()=="*"){
                        start = true;
                        flag="*";
                        s2.append(String.valueOf(s1.toString()));
                        s1.delete(0, s1.length());
                        tf.setText(s1.toString());
                    }
                    //除号
                    if(arg0.getActionCommand()=="/"){
                        start = true;
                        flag="/";
                        s2.append(String.valueOf(s1.toString()));
                        s1.delete(0, s1.length());
                        tf.setText(s1.toString());
                    }
                    //开根号
                    if(arg0.getActionCommand()=="sqrt"){
                        start =false;
                        double s=Double.parseDouble(s1.toString());
                        s1.delete(0, s1.length());
                    tf.setText(s1.append(String.valueOf(Math.sqrt(s))).toString());
                    }
                    //求%
                    if(arg0.getActionCommand()=="%"){
                        start =false;
                        double s=Double.parseDouble(s1.toString());
                        s1.delete(0, s1.length());
                        tf.setText(s1.append(String.valueOf(s/100)).toString());
                    }
                    //求1/x
                    if(arg0.getActionCommand()=="1/x"&&!s1.toString().equals(new String())&&Double.parseDouble(s1.toString())!=0){
                        start =false;
                        double s=Double.parseDouble(s1.toString());
                        s1.delete(0, s1.length());
                        tf.setText(s1.append(String.valueOf(1/s)).toString());
                    }
                    //求结果
                    if(arg0.getActionCommand()=="="&&s1.length()!=0&&s2.length()!=0){
                        //start标记为false
                        start =false;
                        //分别获取s1和s2的值
                        double s4=Double.parseDouble(s1.toString()); 
                        double s3=Double.parseDouble(s2.toString());
                        //清空s1和s2，便于开始下一次运算
                        s1.delete(0, s1.length());
                        s2.delete(0, s2.length());
                        //四则运算
                        if(flag=="+"){
                            tf.setText(s1.append(String.valueOf(s3+s4)).toString());
                        }
                        if(flag=="-"){
                            tf.setText(s1.append(String.valueOf(s3-s4)).toString());
                        }
                        if(flag=="*"){
                            tf.setText(s1.append(String.valueOf(s3*s4)).toString());
                        }
                        if(flag=="/"){
                            tf.setText(s1.append(String.valueOf(s3/s4)).toString());
                        }
                    }       
     
                }
            };
            //添加按钮以及监听器
            JButton bks = new JButton("删除");
            bks.addActionListener(listen);
            JButton ce = new JButton("归零");
            ce.addActionListener(listen);
            JButton c = new JButton("清空");
            c.addActionListener(listen);
            p2.add(bks);
            p2.add(ce);
            p2.add(c);
            f.add(p2);
            JPanel p3 = new JPanel();
            p3.setLayout(new GridLayout(4,5));
            JButton b1 = new JButton("7");
            p3.add(b1);
            b1.addActionListener(listen);
            JButton b2 = new JButton("8");
            p3.add(b2);
            b2.addActionListener(listen);
            JButton b3 = new JButton("9");
            p3.add(b3);
            b3.addActionListener(listen);
            JButton b4 = new JButton("/");
            p3.add(b4);
            b4.addActionListener(listen);
            JButton b5 = new JButton("sqrt");
            p3.add(b5);
            b5.addActionListener(listen);
            JButton b6 = new JButton("4");
            p3.add(b6);
            b6.addActionListener(listen);
            JButton b7 = new JButton("5");
            p3.add(b7);
            b7.addActionListener(listen);
            JButton b8 = new JButton("6");
            p3.add(b8);
            b8.addActionListener(listen);
            JButton b9 = new JButton("*");
            p3.add(b9);
            b9.addActionListener(listen);
            JButton b10 = new JButton("%");
            p3.add(b10);
            b10.addActionListener(listen);
            JButton b11 = new JButton("1");
            p3.add(b11);
            b11.addActionListener(listen);
            JButton b12 = new JButton("2");
            p3.add(b12);
            b12.addActionListener(listen);
            JButton b13 = new JButton("3");
            p3.add(b13);
            b13.addActionListener(listen);
            JButton b14 = new JButton("-");
            p3.add(b14);
            b14.addActionListener(listen);
            JButton b15 = new JButton("1/x");
            p3.add(b15);
            b15.addActionListener(listen);
            JButton b16 = new JButton("0");
            p3.add(b16);
            b16.addActionListener(listen);
            JButton b17 = new JButton("+/-");
            p3.add(b17);
            b17.addActionListener(listen);
            JButton b18 = new JButton(".");
            p3.add(b18);
            b18.addActionListener(listen);
            JButton b19 = new JButton("+");
            p3.add(b19);
            b19.addActionListener(listen);
            JButton b20 = new JButton("=");
            p3.add(b20);
            b20.addActionListener(listen);
            f.add(p3,BorderLayout.SOUTH);
            f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
            f.pack();
            f.setVisible(true);
        }
     
        public static void main(String args[]){
            //调用方法，实现计算器
            new Calculate().init();
        }
     
    
    }

Over！

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyMzIxMzM2_size_16_color_FFFFFF_t_70]: /images/20211029/bd06c2c37aaf420a8d03a921a3de149a.png