KeyListener不响应键盘输入 [英] KeyListener not responding to keyboard input

问题描述

我一直在尝试自己学习更高级的Java(我的课程仅涵盖文本文件)，而我对使用KeyListener感到困惑.我设法使其在另一个程序中工作，但在这里找不到问题.控制台上没有错误显示.该程序使用机械手在文本文件中键入预定义的字符串.这是主班.

I've been trying to learn more advanced java on my own (My class is only covering text files) and I'm stumped on the using KeyListener. I managed to get it to work in another program, but I can't find the problem here. No errors show up on the console. This program uses a robot to type predefined Strings in a text file. Here's the main class.

    import java.awt.AWTException;
    import java.awt.event.KeyEvent;
    import java.awt.event.KeyListener;
    import java.io.File;
    import java.io.FileNotFoundException;
    import java.util.Scanner;

    import javax.swing.SwingUtilities;


    public class FileTyper implements KeyListener {

static Keyboard kb;
static Scanner infile;
static boolean on = false;
static Window window;

public static void main(String args[]) throws AWTException, FileNotFoundException{
    init();
    start();
}
private static void init() throws AWTException, FileNotFoundException{
    window = new Window();
    kb = new Keyboard();
    kb.setSpeed(50);
    infile = new Scanner(new File("C:/Users/Ali/Desktop/input.txt"));

}
private static void start(){
    SwingUtilities.invokeLater(new Runnable() {
        @Override
        public void run() {

            if(on && infile.hasNext()){
                String temp = infile.nextLine();
                kb.type(temp);
                kb.type("\n");
            }
        }
    });
}

@Override
public void keyPressed(KeyEvent e) {

}

@Override
public void keyReleased(KeyEvent e) {
    switch(e.getKeyCode()) {
    case KeyEvent.VK_F9:
        System.out.println("CONSOLE: Starting");
        on = true;
        break;
    case KeyEvent.VK_F10:
        System.out.println("CONSOLE: Stopping");
        on = false;
        break;
    }

}

@Override
public void keyTyped(KeyEvent e) {

}

}

推荐答案

• 要使KeyListener正常工作，必须首先通过addKeyListener(...)将其 添加 到组件中.您不这样做，除非有机会，否则它将不起作用.
• 正如camickr所述，KeyListener要求其侦听的组件具有焦点.
• 通常最好不要在Swing应用程序中使用KeyListener，而应使用 Key绑定.
• 射门，您甚至根本没有任何可见的GUI，因此，您甚至需要考虑对教程进行更多研究，以首先使您的gui正常运行，甚至不考虑添加KeyListener或使用键绑定.
• For a KeyListener to work, you must first add it to a component via addKeyListener(...). You don't do this, and it won't work unless it has a chance to.
• As camickr notes, a KeyListener requires that the component it listens to has focus.
• Usually it's better not to use KeyListeners in Swing apps but to use Key Bindings.
• Shoot, you don't even have a visible GUI of any kind at all, so you really need to do more studying of the tutorials to first get your gui up and running before even considering adding a KeyListener or use Key Bindings.

修改
您声明:

Edit
You state:

如果在最小化程序窗口时想使用KeyListener怎么办?
我的意思是使用快捷键来暂停启动或停止程序

What if I wanted to use KeyListener when the program window is minimized?
I mean use a shortcut key to pause the start or stop the program

Core Java本身无法执行此操作.为此，您需要使用JNI或JNA扩充Java或使用特定于操作系统的实用程序.我已经在Windows应用程序中使用了AutoIt.

Core Java by itself cannot do this. For this to work, you either need to augment Java with JNI or JNA or use an OS-specific utility program. I've used AutoIt for my Windows apps.

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