如何检查 java 中单击事件时是否按下了键

Question

我想在按下按键（不是 ctrl、shift 或 alt）时捕获 java 中的 Clicked 事件，或者检查按键 "A" 是否按下并按下按键 "D" .我该怎么做，比如 isshiftdown 方法？

Answer 1

像这样添加鼠标侦听器：

component.addMouseListener(new MouseAdapter(){
  public void mousePressed(MouseEvent e){
    mouseDown = true;
  }
  public void mouseReleased(MouseEvent e){
    mouseDown = false;
  }
});

和主要听众：

component.addKeyListener(new KeyAdapter(){
  public void keyPressed(KeyEvent e){
    if(mouseDown){
      System.out.println("the key was pressed while the mouse is down.");
    }
  }
});

Answer 2

不确定这是否是您想要的。您可以使用 java.awt.event 包中的一些东西，称为 KeyEvent。

这是一个完整的例子：

https://docs.oracle.com/javase/tutorial/displayCode.html?code=https://docs.oracle.com/javase/tutorial/uiswing/examples/events/KeyEventDemoProject/src/events/KeyEventDemo.java

复制到你自己的IDE并给它一个运行

Answer 3

我喜欢做的是有一个布尔数组来存储当前按下的键，然后在需要时使用其他方法访问它们。例如...

Boolean[] keys = new Boolean[256];
Boolean mousePressed = false;
...
keyPressed(MouseEvent e) {
    keys[e.getKeyCode()] = true;
}
...
keyReleased (MouseEvent e) {
    keys[e.getKeyCode()] = false;
}
....
mousePressed (MouseEvent e) { mousePressed=true; }

然后，无论何时您需要查看它是否按下了组合键，只需引用该数组并查看该键当前是否为真。它同样适用于鼠标和按键侦听器。

Answer 4

您可以通过创建一个布尔值数组来实现，当按下键时将该键的布尔值设置为 true，当未按下时将其设置为 false。

public boolean[] key = new boolean[68836];

不要问我为什么是68836... 您的 class 看起来像这样：

public class keyHandler implements KeyListener, MouseListener{

int KeyCode = 0;
Main main;

    public KeyHandler(Main main){
        this.main = main;
    }
    public void keyPressed(KeyEvent e) {
        keyCode = e.getKeyCode();

        if (keyCode > 0 && keyCode < key.length) {
            main.key[keyCode] = true;
        }
    }
    public void keyReleased(KeyEvent e) {
        keyCode = e.getKeyCode();

        if (keyCode > 0 && keyCode < key.length) {
            main.key[keyCode] = false;
        }
    }
    public void mousePressed(MouseEvent e) {
        main.MouseButton = e.getButton();
        main.MousePressed true;
    }

    public void mouseReleased(MouseEvent e) {
        main.MouseButton = 0;
        main.MousePressed = false;
    }
}

接下来您将有某种循环 class 以允许您定期检查布尔值：

public class Time extends Thread{
    Main main;
    public Time(Main main){
        this.main = main;
    }
    public void run(){
        while(true){
            main.update();// you would probably want some timing system here
        }
    }
}

然后在你的主要 class 或其他东西中：

public class Main {
//whatever you have here
public boolean[] key = new boolean[68836];
int MouseButton = 0;
boolean MousePressed = false;

    public Main(){
        Component c; //whatever you are using e.g JFrame
        //whatever you do to your component
        KeyHandler kh = new KeyHandler(this);
        c.addKeyListener(kh);
        c.addMouseListener(kh);
    }

    public void update(){
        if(key[KeyEvent.VK_A] && key[KeyEvent.VK_D){
            //both keys are pressed
        }
    }
}

如何检查 java 中单击事件时是否按下了键

How to check if key pressed when clicked event in java

java

event-handling

mouseevent

keyboard-events