TA貢獻1793條經驗 獲得超6個贊
在Java中，你不檢查是否有鍵被按下，而不是你聽到KeyEvent秒。實現目標的正確方法是注冊KeyEventDispatcher并實現它以維護所需鍵的狀態：
import java.awt.KeyEventDispatcher;import java.awt.KeyboardFocusManager;import java.awt.event.KeyEvent;public class IsKeyPressed {
private static volatile boolean wPressed = false;
public static boolean isWPressed() {
synchronized (IsKeyPressed.class) {
return wPressed;
}
}
public static void main(String[] args) {
KeyboardFocusManager.getCurrentKeyboardFocusManager().addKeyEventDispatcher(new KeyEventDispatcher() {
@Override
public boolean dispatchKeyEvent(KeyEvent ke) {
synchronized (IsKeyPressed.class) {
switch (ke.getID()) {
case KeyEvent.KEY_PRESSED:
if (ke.getKeyCode() == KeyEvent.VK_W) {
wPressed = true;
}
break;
case KeyEvent.KEY_RELEASED:
if (ke.getKeyCode() == KeyEvent.VK_W) {
wPressed = false;
}
break;
}
return false;
}
}
});
}}然后你總是可以使用：
if (IsKeyPressed.isWPressed()) {
// do your thing.}當然，您可以使用相同的方法來實現isPressing("<some key>")密鑰映射及其內部包含的狀態IsKeyPressed。
TA貢獻1827條經驗 獲得超8個贊
試試這個：
import java.awt.event.KeyAdapter;import java.awt.event.KeyEvent;import javax.swing.JFrame;import javax.swing.JTextField;public class Main {
public static void main(String[] argv) throws Exception {
JTextField textField = new JTextField();
textField.addKeyListener(new Keychecker());
JFrame jframe = new JFrame();
jframe.add(textField);
jframe.setSize(400, 350);
jframe.setVisible(true);}class Keychecker extends KeyAdapter {
@Override
public void keyPressed(KeyEvent event) {
char ch = event.getKeyChar();
System.out.println(event.getKeyChar());}舉報