我对Java KeyAdapter
的工作方式有些陌生,并且使用KeyAdapter
的以下代码正在获得意想不到的结果。无论是否调用isKeyPressed()
,都在按住另一个键的同时按下一个键,就会出现问题。
注意:我知道这是很多代码,对此我深表歉意。我尽力将其隔离,我认为它主要位于下面keyHandler
方法中的注释周围(keyHandler()
如何将当前按下的键放入keysHeld
中)。希望详尽的评论对您有所帮助。
keyHandler:
ArrayList keysHeld = new ArrayList<KeyEvent>();
private void keyHandler()
{
KeyAdapter keyListnr = new KeyAdapter()
{
public void keyPressed(KeyEvent e)
{
int keyCode = e.getKeyCode();
int index = 0;
boolean found = false;
while(!found && index<keysHeld.size()) //While not already found, and end of ArrayList not reached
{
System.out.print("errorCheck: keysHeld: "+keysHeld+", "+(Object)keyCode+" "); //PRINT
if(keysHeld.get(index) == (Object)keyCode)
{
System.out.println("found"); //PRINT
found = true; //This key is already recognized as held
}
else
{
System.out.println("not found"); //PRINT
//This key is not recognized as held
}
}
if(!found) //If key must be added to keysHeld
{
keysHeld.add(keyCode); //Add to list of held keys
}
System.out.println(keysHeld.toString()); //PRINT ArrayList of all held keys
} //end of keyPressed
public void keyReleased(KeyEvent e) //similar in concept to keyPressed
{
int keyCode = e.getKeyCode();
int index = 0;
boolean found = false;
while(!found && index < keysHeld.size())
{
if(keysHeld.get(index) == (Object)keyCode)
{
keysHeld.remove(index); //remove key from keysHeld
found = true;
}
else
{
index++;
}
}
System.out.println(keysHeld.toString()); //PRINT ArrayList of all held keys
} //end of keyReleased
};
addKeyListener( keyListnr );
}
isKeyHeld:
public boolean isKeyHeld(int e)
{
int keyCode = e;
Object key = (Object)keyCode;
if(!keysHeld.isEmpty())
{
int index = 0;
while(index<keysHeld.size())
{
if(keysHeld.get(index) == key)
{
return true;
}
index++;
}
}
return false;
}
控制台输出:(按住leftArrow [37],然后按rightArrow [39])
[37]
errorCheck: keysHeld: [37], 39 not found
errorCheck: keysHeld: [37], 39 not found
errorCheck: keysHeld: [37], 39 not found
errorCheck: keysHeld: [37], 39 not found
...
最佳答案
几点:
您不会使用keysHeld
实例来填充KeyEvent
数组,而是使用从Integer
keyCodes派生的autoBoxed int
对象。
如果要退出index
中的while
循环,则需要增加keyPressed
变量。
您不应该使用==
来比较Objects
循环中的两个while
您可以使用以下内容进行测试:
if(keysHeld.get(index++).equals(new Integer(keyCode))