用Java编写一个猜数字的程序

Question

编写一个猜数字的程序，窗口标题为“猜数字”，布局策略为FlowLayout布局5窗口中有两个按钮，分别为“产生一个随机数”按钮和“确定”按钮。另外，窗口中还有一个标签，苡及一个文举框。/当用户单击“产生一个随机数”按钮时可以获得一个随机 (整)数，然后在一个文本框中输入猜测的数字后再单击“确定”按钮时，程序将用户猜测的数字与随机数进行比较，如果相同，则在标签上显示“猜对了!”;如果猜测的数字大于随机数，则在标签上提示“猜大了!”;如果猜测的数字小于随机数，则在标签上提示“猜小了!”。

注:考虑到文本框中输入的内容有非数字的可能性，要求程序处理NumberFormatException异常(处理方式不限制)。

提示:产生一个随机整数的方法可利用Math类里的random( )方法，如: (int)(Math.random() *100)

Answer 1

参考一下：

<span class="hljs-keyword">import</span> java.awt.FlowLayout;
<span class="hljs-keyword">import</span> java.awt.event.ActionEvent;
<span class="hljs-keyword">import</span> java.awt.event.ActionListener;
<span class="hljs-keyword">import</span> javax.swing.JButton;
<span class="hljs-keyword">import</span> javax.swing.JComboBox;
<span class="hljs-keyword">import</span> javax.swing.JFrame;
<span class="hljs-keyword">import</span> javax.swing.JPanel;
<span class="hljs-keyword">import</span> javax.swing.JTextField;

<span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">class</span> 简单计算器  <span class="hljs-keyword"><span class="hljs-keyword">extends</span> <span class="hljs-type">JFrame</span></span> <span class="hljs-keyword"><span class="hljs-keyword">implements</span> <span class="hljs-type">ActionListener</span></span></span>{
    JTextField txtNum1,txtNum2,txtNum3;
    JComboBox<<span class="hljs-keyword">String</span>> cbOpr;
    <span class="hljs-keyword">String</span> opr[] = {<span class="hljs-string">"+"</span>,<span class="hljs-string">"-"</span>,<span class="hljs-string">"*"</span>,<span class="hljs-string">"/"</span>};
    JButton btnCalc;
    <span class="hljs-keyword">public</span> 简单计算器() {
        <span class="hljs-keyword">super</span>(<span class="hljs-string">"简单计算器"</span>);
        
        txtNum1 = <span class="hljs-keyword">new</span> <span class="hljs-type">JTextField</span>(<span class="hljs-number">6</span>);
        cbOpr = <span class="hljs-keyword">new</span> <span class="hljs-type">JComboBox</span><<span class="hljs-keyword">String</span>>(opr);
        txtNum2 = <span class="hljs-keyword">new</span> <span class="hljs-type">JTextField</span>(<span class="hljs-number">6</span>);
        txtNum3 = <span class="hljs-keyword">new</span> <span class="hljs-type">JTextField</span>(<span class="hljs-number">6</span>);
        btnCalc = <span class="hljs-keyword">new</span> <span class="hljs-type">JButton</span>(<span class="hljs-string">"="</span>);
        JPanel northPane = <span class="hljs-keyword">new</span> <span class="hljs-type">JPanel</span>(<span class="hljs-keyword">new</span> <span class="hljs-type">FlowLayout</span>());
        northPane.add(txtNum1);
        northPane.add(cbOpr);
        northPane.add(txtNum2);
        northPane.add(btnCalc);
        northPane.add(txtNum3);
        txtNum3.setEnabled(<span class="hljs-literal">false</span>);
        add(northPane);
        btnCalc.addActionListener(<span class="hljs-built_in">this</span>);
        <span class="hljs-built_in">this</span>.pack();
        setVisible(<span class="hljs-literal">true</span>);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLocationRelativeTo(<span class="hljs-literal">null</span>);
        
    }
    @Override
    <span class="hljs-keyword">public</span> void actionPerformed(ActionEvent e) {
        
        <span class="hljs-keyword">try</span> {
            double num1 = Double.parseDouble(txtNum1.getText());
            double num2 = Double.parseDouble(txtNum2.getText());
            int index = cbOpr.getSelectedIndex();
            <span class="hljs-keyword">switch</span>(index) {
            <span class="hljs-keyword">case</span> <span class="hljs-number">0</span>:<span class="hljs-type"></span>
                txtNum3.setText((num1+num2)+<span class="hljs-string">""</span>);
                <span class="hljs-keyword">break</span>;
            <span class="hljs-keyword">case</span> <span class="hljs-number">1</span>:<span class="hljs-type"></span>
                txtNum3.setText((num1-num2)+<span class="hljs-string">""</span>);
                <span class="hljs-keyword">break</span>;
            <span class="hljs-keyword">case</span> <span class="hljs-number">2</span>:<span class="hljs-type"></span>
                txtNum3.setText((num1*num2)+<span class="hljs-string">""</span>);
                <span class="hljs-keyword">break</span>;
            <span class="hljs-keyword">case</span> <span class="hljs-number">3</span>:<span class="hljs-type"></span>
                txtNum3.setText((num1/num2)+<span class="hljs-string">""</span>);
                <span class="hljs-keyword">break</span>;
            }
        }<span class="hljs-keyword">catch</span>(Exception ex){
            System.out.println(<span class="hljs-string">"出错了"</span>+ex.getMessage());
        }
    }
    <span class="hljs-keyword">public</span> <span class="hljs-keyword">static</span> void main(<span class="hljs-keyword">String</span>[] args) {
        <span class="hljs-keyword">new</span> <span class="hljs-type"></span>简单计算器();
    }
}