我正在使用 Eclipse使用OpenJDK开发java应用程序 在Ubuntu 10.10上
当使用带有Jframe的密钥列表时，Keylistner可以完美地工作直到帧具有焦点，但是如果开关聚焦到另一个应用程序然后将焦点返回到Jframe，则此时它不会开始听到按键。 我需要做的是当框架重新获得焦点时，keylistener应该再次开始工作。我的申请中只有一个框架。
我已经实现了KeyListner，将其添加到JFrame：
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import code.NewJFrame;
public class Gamepad implements KeyListener
{
boolean button_up;
boolean button_down;
boolean button_right;
boolean button_left;
boolean b1;
boolean b2;
boolean b3;
boolean b4;
boolean select;
boolean start;
boolean r1;
boolean r2;
boolean l1;
boolean l2;
boolean joyl_up;
boolean joyl_down;
boolean joyl_right;
boolean joyl_left;
boolean joyr_up;
boolean joyr_down;
boolean joyr_right;
boolean joyr_left;
final static char BUTTON_UP ='Q' ;
final static char BUTTON_DOWN='W';
final static char BUTTON_RIGHT='E';
final static char BUTTON_LEFT='R';
final static char B1='T';
final static char B2='Y';
final static char B3='U';
final static char B4='I';
final static char SELECT='O';
final static char START='P';
final static char R1='A';
final static char R2='S';
final static char L1= 'D';
final static char L2= 'F';
final static char JOYL_UP='G';
final static char JOYL_DOWN='H';
final static char JOYL_RIGHT='J';
final static char JOYL_LEFT='K';
final static char JOYR_UP='L';
final static char JOYR_DOWN='Z';
final static char JOYR_RIGHT='X';
final static char JOYR_LEFT='C';
public Gamepad()
{
button_up = false;
button_down= false;
button_right= false;
button_left= false;
b1= false;
b2= false;
b3= false;
b4= false;
select= false;
start= false;
r1= false;
r2= false;
l1= false;
l2= false;
}
/**
* @param args
*/
public static void main(String[] args)
{
NewJFrame nj = new NewJFrame();
Gamepad gp = new Gamepad();
nj.addKeyListener(gp);
nj.setVisible(true);
}
@Override
public void keyPressed(KeyEvent e)
{
char c= Character.toUpperCase( e.getKeyChar() );
System.out.println("PRESSED:\t"+c);
if(c==BUTTON_UP) button_up=true;
else if(c==BUTTON_DOWN) button_down=true;
else if(c==BUTTON_RIGHT) button_right=true;
else if(c==BUTTON_LEFT) button_left=true;
else if(c==B1) b1=true;
else if(c==B2) b2=true;
else if(c==B3) b3=true;
else if(c==B4) b4=true;
else if(c==SELECT) select=true;
else if(c==START) { start=!start; Global.playToggle();}
else if(c==R1) r1=true;
else if(c==R2) r2=true;
else if(c==L1) l1=true;
else if(c==L2) l2 =true;
else if(c==JOYL_DOWN) joyl_down =true;
else if(c==JOYL_LEFT) joyl_left =true;
else if(c==JOYL_RIGHT) joyl_right =true;
else if(c==JOYL_UP) joyl_up =true;
else if(c==JOYR_DOWN) joyr_down =true;
else if(c==JOYR_LEFT) joyr_left =true;
else if(c==JOYR_RIGHT) joyr_right =true;
else if(c==JOYR_UP) joyr_up =true;
}
@Override
public void keyReleased(KeyEvent e)
{
char c= Character.toUpperCase( e.getKeyChar() );
System.out.println("RELEASED:\t"+e.getKeyChar());
if(c==BUTTON_UP) button_up=true;
else if(c==BUTTON_DOWN) button_down=false;
else if(c==BUTTON_RIGHT) button_right=false;
else if(c==BUTTON_LEFT) button_left=false;
else if(c==B1) b1=false;
else if(c==B2) b2=false;
else if(c==B3) b3=false;
else if(c==B4) b4=false;
else if(c==SELECT) select=false;
else if(c==START) ;//{start=false; Global.playToggle();}
else if(c==R1) r1=false;
else if(c==R2) r2=false;
else if(c==L1) l1=false;
else if(c==L2) l2 =false;
else if(c==JOYL_DOWN) joyl_down =false;
else if(c==JOYL_LEFT) joyl_left =false;
else if(c==JOYL_RIGHT) joyl_right =false;
else if(c==JOYL_UP) joyl_up =false;
else if(c==JOYR_DOWN) joyr_down =false;
else if(c==JOYR_LEFT) joyr_left =false;
else if(c==JOYR_RIGHT) joyr_right =false;
else if(c==JOYR_UP) joyr_up =false;
}
@Override
public void keyTyped(KeyEvent e)
{
// TODO Auto-generated method stub
}
}
答案 0 :(得分：1)
我自己在Linux（gnome）中遇到了keylistener / window焦点问题。
我做了一些追踪并发现： 1）当您单击窗口时，不会触发LOST FOCUS（不会触发焦点事件）。 2）重新获得焦点/点击窗口，使其触发LOST FOCUS事件，而不是增益焦点。
现在似乎对我有用的修复：
frame.addFocusListener(new FocusListener(){
public void focusGained(FocusEvent e){
System.out.println("Focus GAINED:"+e);
}
public void focusLost(FocusEvent e){
System.out.println("Focus LOST:"+e);
// FIX FOR GNOME/XWIN FOCUS BUG
e.getComponent().requestFocus();
}
});
基本上在焦点丢失时请求焦点。对于Windows用户来说似乎没有破坏任何东西，当你失去焦点时，图标可能会在你的开始栏上闪烁，更糟糕的是。
另外，如果你想像我一样进行调试，那么这就是代码：
Toolkit.getDefaultToolkit().addAWTEventListener( new AWTEventListener(){
public void eventDispatched(AWTEvent e) {
System.out.println("AWT:"+e);
System.out.flush();
}
}, FocusEvent.FOCUS_EVENT_MASK | WindowEvent.WINDOW_FOCUS_EVENT_MASK | WindowEvent.WINDOW_EVENT_MASK);
希望这有助于某人！