Question

我一直在尝试几种方法来编写一个小程序，允许用户根据他们点击的按钮运行三种功能中的一种。主程序的代码如下：

public class WaspmoteSim extends JFrame implements ActionListener {
public WaspmoteSim() {
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    getContentPane().setLayout(new GridBagLayout());
    GridBagConstraints c = new GridBagConstraints();
    c.insets = new Insets(30,30,30,30);
    c.ipadx = 10;
    c.ipady = 30;
    setSize(700, 150);
    setLocation(100, 100);

    JButton button1 = new JButton("Demonstration Mode");
    button1.addActionListener(this);
    add(button1, c);

    JButton button2 = new JButton("Distribution Fitting Mode");
    button2.addActionListener(this);
    add(button2, c);

    JButton button3 = new JButton("Operational Mode");
    button3.addActionListener(this);
    add(button3, c);

    setVisible(true);
    setFocusable(true);
}
public static void main(String[] args) {

}

@Override
public void actionPerformed(ActionEvent e) {
    String command = e.getActionCommand();

    if (command.equals("Demonstration Mode")) {
        try {
            DemoMethod();
        } catch (IOException ex) {
            Logger.getLogger(WaspmoteSim.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
    if (command.equals("Distribution Fitting Mode")) {
        try {
            FittingMethod();
        } catch (IOException ex) {
            Logger.getLogger(WaspmoteSim.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
    if (command.equals("Operational Mode")) {
        try {
            OperationsMethod();
        } catch (IOException ex) {
            Logger.getLogger(WaspmoteSim.class.getName()).log(Level.SEVERE, null, ex);
        } catch (InterruptedException ex) {
            Logger.getLogger(WaspmoteSim.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
    //else {ProcessHolder.getInstance().getProcesses().get(YOUR_PROCESS_NAME).destroy();}
}

并且第三个按钮需要调用的函数（我希望能够中断的函数）如下所示：

public void OperationsMethod() throws IOException, InterruptedException {
        Process proc;
        while(!IsKeyPressed.isEPressed()) {
            String workingDir = System.getProperty("user.dir");
            System.out.println(workingDir);
            proc = Runtime.getRuntime().exec("cmd.exe /C C:\\Progra~1\\R\\R-3.2.1.\\bin\\Rscript.exe " + workingDir + "\\Fitter.r");
            TimeUnit.SECONDS.sleep(4);
        }
    }

IsKeyPressed的代码直接来自How do I check if the user is pressing a key?。

然而，当运行第三个功能并按住/按住E键时，程序只是继续循环。我做错了什么？

Answer 1

您正在Swing事件调度线程中启动无限循环。这意味着您的actionPerformed方法永远不会结束。这意味着Swing被阻止，无法处理任何新的按钮点击或任何其他类型的事件。

使用SwingWorker启动OperationsMethod()。并使用共享和同步变量来共享Swing类和SwingWorker之间的按钮状态。

如何让用户在Java中中断无限循环？

1 个答案: