java计算器页面设计

今天学习了Java的GUI图形界面，并实现了如下图所示的复杂计算器界面的设计，在设计算器界面的整个过程中遇到了不少小问题，值得注意和总结。

由于计算器界面较复杂，按键较多，因此需要用到面板的嵌套，但是面板为二级容器，不能单独出现，必须依赖于窗口。

其中代码如下：

public class CalTest extends JFrame {
    
    public CalTest(){
        this.setSize(820,680);
        this.setTitle("计算器");
        this.setLayout(null);
        initPanel1();
        initPanel2();
        initPanel3();
        initPanel5();
        initPrintText();
        initHelp();
        this.setVisible(true);
    }
//面板1，25个按键
    private void initPanel1() {
        JPanel Panel1 = new JPanel();
        Panel1.setSize(350, 350);
        Panel1.setLocation(50, 230);
        Panel1.setLayout(new GridLayout(5,5,3,3));
        Panel1.setBackground(Color.WHITE);
        JButton[] btsl = new JButton[25];
        String[] strs = {" ", "Inv", "In", "(", ")", "Int", "sinh", "sin", "x^2", "n!", "dms", "cosh", "cos", "x^y", "y|x", "3.14", "tanh", "tan", "x^3", "3|x", "F-E","Exp","Mod","log","10^x"};
        for (int i = 0; i < strs.length; i++) {
            btsl[i] = new JButton(strs[i]);
            Panel1.add(btsl[i]);
        }
        btsl[0].setEnabled(false);
        this.add(Panel1);
    }
//面板2，20个按键
    private void initPanel2(){
        JPanel panel2 = new JPanel();
        panel2.setSize(350,280);
        panel2.setLocation(402,160);
        panel2.setLayout(new GridLayout(4,5,3,3));
        panel2.setBackgroun/d(Color.WHITE);
        JButton[] btsl2 = new JButton[20];
        String[] strs2 = {"MC","MR","M5","M+","M-","<——","CE","C","+-","根号","7","8","9","/","%","4","5","6","*","1/x"};
        for (int i = 0; i < strs2.length ; i++) {
            btsl2[i] = new JButton(strs2[i]);
            panel2.add(btsl2[i]);
        }
        this.add(panel2);
    }
    //对特殊位置的按键进行处理
    private void initPanel3(){
        initPanel4();

        JButton button1 = new JButton("1");
        button1.setSize(67,67);
        button1.setLocation(402,440);
        this.add(button1);

        JButton button2 = new JButton("2");
        button2.setSize(67,67);
        button2.setLocation(472,440);
        this.add(button2);

        JButton button3 = new JButton("0");
        button3.setSize(137,67);
        button3.setLocation(402,510);
        this.add(button3);

        JButton button4 = new JButton("=");
        button4.setSize(67,137);
        button4.setLocation(684,441);
        this.add(button4);
    }
    //面板4，4个按键
    private void initPanel4(){
        JPanel Panel4 = new JPanel();
        Panel4.setSize(140,140);
        Panel4.setLocation(542,440);
        Panel4.setLayout(new GridLayout(2,2,3,3));
        Panel4.setBackground(Color.WHITE);
        JButton[] btsl4 = new JButton[4];
        String[] strs4 = {"3","——",".","+"};
        for (int i = 0; i < strs4.length ; i++) {
            btsl4[i] = new JButton(strs4[i]);
            Panel4.add(btsl4[i]);
        }
        this.add(Panel4);
    }
//面板5，3个按键
    private void initPanel5(){
        JPanel panel5 = new JPanel();
        panel5.setSize(347,67);
        panel5.setLocation(50,160);
        panel5.setLayout(new GridLayout(1,3,10,10));
        JButton[] btls5 = new JButton[3];
        String[] strs = {"度","弧度","梯度"};
        for (int i = 0; i < strs.length ; i++) {
            btls5[i] = new JButton(strs[i]);
            panel5.add(btls5[i]);
        }
        this.add(panel5);
    }
//输出框
    private void initPrintText(){
        JTextField printText = new JTextField();
        printText.setSize(702,100);
        printText.setLocation(50,50);
        this.add(printText);
    }
//顶部的帮助按键
    private void initHelp(){
        JPanel panel6 = new JPanel();
        panel6.setSize(400,40);
        panel6.setLocation(50,0);
        panel6.setLayout(new GridLayout(1,3,10,10));
        JButton[] btls5 = new JButton[3];
        String[] strs = {"查看(v)","编辑(E)","帮助(H)"};
        for (int i = 0; i < strs.length ; i++) {
            btls5[i] = new JButton(strs[i]);
            panel6.add(btls5[i]);
        }
        this.add(panel6);
    }
}
           

在主方法中调用就可以运行成功

在编写代码中遇到了一些小问题需要注意

1.布局时坐标是按照此控件左上角到窗口的距离来确定x，y坐标的。

2.大窗口的尺寸要足够大，控件的尺寸大小和坐标中和不能超过大窗口的尺寸，否则运行时窗口不能显示完全。

3.在使用对象设置相应参数时要注意不能用this来代替当前对象，因为此时this指向调用当前方法的对象，不能搞混淆。

例如： panel6.setSize(400,40);就不能写成 this.setSize(400,40);

4.按钮一定要add到相应面板上，面板要add到窗口上

5.设置可见：this.setVisible(true);否则窗口不会显示相应控件