Spring 做一个计算器界面(解决控件覆盖问题）

  1 import java.awt.BorderLayout;
  2
  3 import javax.swing.*;
  4 public class ForJava {
  5
  6     public static void main(String[] args) {
  7         JFrame frame=new CCal(400,300);
  8         frame.setVisible(true);
  9     }
 10 }
 11 class CCal extends JFrame{
 12     public CCal(int w,int h){
 13         setLocation(200, 160);
 14         setSize(w, h);
 15         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 16
 17
 18         JPanel displayPanel=new JPanel();
 19         JButton cbtn=new JButton();
 20         cbtn.setText("c");
 21         displayPanel.add(cbtn);
 22
 23         JTextArea display=new JTextArea();
 24         display.setColumns(20);
 25         displayPanel.add(display);
 26         getContentPane().add(displayPanel, BorderLayout.NORTH);
 27
 28         JPanel panelTemp1=new JPanel();
 29         panelTemp1.setLayout(new BorderLayout());
 30         getContentPane().add(panelTemp1);
 31
 32         JPanel cachePanel=new JPanel();
 33         panelTemp1.add(cachePanel, BorderLayout.NORTH);
 34         JButton mbtnMR=new JButton();
 35         mbtnMR.setText("MR");
 36         cachePanel.add(mbtnMR);
 37         JButton mbtnMC=new JButton();
 38         mbtnMC.setText("MC");
 39         cachePanel.add(mbtnMC);
 40         JButton mbtnMS=new JButton();
 41         mbtnMS.setText("MS");
 42         cachePanel.add(mbtnMS);
 43         JButton mbtnMP=new JButton();
 44         mbtnMP.setText("M+");
 45         cachePanel.add(mbtnMP);
 46
 47
 48         JPanel panelTemp2=new JPanel();
 49         panelTemp2.setLayout(new BorderLayout());
 50         panelTemp1.add(panelTemp2);
 51
 52         JPanel panelButton1=new JPanel();
 53         panelTemp2.add(panelButton1, BorderLayout.NORTH);
 54         JButton mbtn1=new JButton();
 55         mbtn1.setText("1");
 56         panelButton1.add(mbtn1);
 57         JButton mbtn2=new JButton();
 58         mbtn2.setText("2");
 59         panelButton1.add(mbtn2);
 60         JButton mbtn3=new JButton();
 61         mbtn3.setText("3");
 62         panelButton1.add(mbtn3);
 63         JButton mbtnP=new JButton();
 64         mbtnP.setText("+");
 65         panelButton1.add(mbtnP);
 66
 67         JPanel panelTemp3=new JPanel();
 68         panelTemp3.setLayout(new BorderLayout());
 69         panelTemp2.add(panelTemp3);
 70
 71         JPanel panelButton2=new JPanel();
 72         panelTemp3.add(panelButton2, BorderLayout.NORTH);
 73         JButton mbtn4=new JButton();
 74         mbtn4.setText("4");
 75         panelButton2.add(mbtn4);
 76         JButton mbtn5=new JButton();
 77         mbtn5.setText("5");
 78         panelButton2.add(mbtn5);
 79         JButton mbtn6=new JButton();
 80         mbtn6.setText("6");
 81         panelButton2.add(mbtn6);
 82         JButton mbtnMi=new JButton();
 83         mbtnMi.setText("-");
 84         panelButton2.add(mbtnMi);
 85
 86         JPanel panelTemp4=new JPanel();
 87         panelTemp4.setLayout(new BorderLayout());
 88         panelTemp3.add(panelTemp4);
 89
 90         JPanel panelButton3=new JPanel();
 91         panelTemp4.add(panelButton3, BorderLayout.NORTH);
 92         JButton mbtn7=new JButton();
 93         mbtn7.setText("7");
 94         panelButton3.add(mbtn7);
 95         JButton mbtn8=new JButton();
 96         mbtn8.setText("8");
 97         panelButton3.add(mbtn8);
 98         JButton mbtn9=new JButton();
 99         mbtn9.setText("9");
100         panelButton3.add(mbtn9);
101         JButton mbtnMu=new JButton();
102         mbtnMu.setText("*");
103         panelButton3.add(mbtnMu);
104
105         JPanel panelTemp5=new JPanel();
106         panelTemp5.setLayout(new BorderLayout());
107         panelTemp4.add(panelTemp5);
108
109         JPanel panelButton4=new JPanel();
110         panelTemp5.add(panelButton4, BorderLayout.NORTH);
111         JButton mbtn0=new JButton();
112         mbtn0.setText("0");
113         panelButton4.add(mbtn0);
114         JButton mbtnPorM=new JButton();
115         mbtnPorM.setText("+/-");
116         panelButton4.add(mbtnPorM);
117         JButton mbtnEq=new JButton();
118         mbtnEq.setText("=");
119         panelButton4.add(mbtnEq);
120         JButton mbtnDiv=new JButton();
121         mbtnDiv.setText("/");
122         panelButton4.add(mbtnDiv);
123     }
124
125
126 }

要使几行按钮排列不被重叠，就需要JPanel的嵌套：

 1 JPanel up1=new JPanel();
 2 /*增加button等*/
 3 getContentPane().add(up1,BorderLayout.north));
 4
 5 JPanel down1 = new JPanel();
 6 down1.setLayout(new BorderLayout());
 7 getContentPane().add(down1,BorderLayout.north));
 8 /*down1不增加button这些控件，只作为下一个Jpanel的底层/*
 9
10 JPanel up2 = new JPanel();
11 down1.add(up2,BorderLayout.NORTH));
12 /*添加控件*/
13
14 JPanel down2 = new Jpanel();
15 down2.setLayout(new BorderLayout());
16 down1.add(down2);
17 //.......................