java - 如何创建按键事件

Question

当我创建 KeyListener 时，它需要以下字段:

public void keyPressed(KeyEvent e) 
{

}
public void keyReleased(KeyEvent e) 
{

}
public void keyTyped(KeyEvent e) 
{

}

当我将 System.out.println(e) 放入 keyPressed 方法时，当我按下回车键时它会返回:

java.awt.event.KeyEvent[KEY_PRESSED,keyCode=10,keyText=?,keyChar=?,keyLocation=KEY_LOCATION_STANDARD,rawCode=0,primaryLevelUnicode=0,scancode=0] on javax.swing.JButton[,1,1,100x100,alignmentX=0.0,alignmentY=0.5,border=com.apple.laf.AquaButtonBorder$Dynamic@13b33a0e,flags=288,maximumSize=,minimumSize=,preferredSize=,defaultIcon=,disabledIcon=,disabledSelectedIcon=,margin=javax.swing.plaf.InsetsUIResource[top=0,left=2,bottom=0,right=2],paintBorder=true,paintFocus=true,pressedIcon=,rolloverEnabled=false,rolloverIcon=,rolloverSelectedIcon=,selectedIcon=,text=HI,defaultCapable=true]

这显然不是KeyEvent，所以我不能用它来调用keyPressed(KeyEvent e)。我想要做的是模拟一个键的按下，特别是输入键，以激活 keyListener 并将该文本输出到 JTextArea 的方式。

注意:我查看了 How can I perfectly simulate KeyEvents? 的已接受答案，并且对它的实际工作原理了解甚少，我想要我理解的代码。我也看过这里How to simulate keyboard presses in java? ，但不是我无法让机器人工作；应该按下某个键时什么也没发生。

Answer 1

e 是 KeyEvent。

如果你想看e值，那么你可以试试这个

System.out.println(e.getKeyChar());

创建 KeyEvent :

KeyEvent e = new KeyEvent(Component source, int id, long when, int modifiers, int keyCode, char keyChar, int keyLocation);

示例(不知道这是不是正确的方法，但它会产生正确的输出):

Button a = new Button("click");
    KeyEvent e;
    e = new KeyEvent(a, 1, 20, 1, 10, 'a');
    System.out.println(""+e.getKeyChar());
    System.out.println(""+e.getKeyCode());

这是所有类型的 KeyEvent 参数

java.​awt.​event.​KeyEvent
@Deprecated public KeyEvent(Component source, int id, long when, int modifiers, int keyCode)
Deprecated. as of JDK1.1

===

java.​awt.​event.​KeyEvent
public KeyEvent(Component source, int id, long when, int modifiers, int keyCode, char keyChar)
Constructs a KeyEvent object.
Note that passing in an invalid id results in unspecified behavior. This method throws an IllegalArgumentException if source is null.
Parameters:
source - the Component that originated the event id - an integer identifying the type of event when - a long integer that specifies the time the event occurred modifiers - the modifier keys down during event (shift, ctrl, alt, meta) Either extended _DOWN_MASK or old _MASK modifiers should be used, but both models should not be mixed in one event. Use of the extended modifiers is preferred. keyCode - the integer code for an actual key, or VK_UNDEFINED (for a key-typed event) keyChar - the Unicode character generated by this event, or CHAR_UNDEFINED (for key-pressed and key-released events which do not map to a valid Unicode character) 
Throws:
IllegalArgumentException - if id is KEY_TYPED and keyChar is CHAR_UNDEFINED; or if id is KEY_TYPED and keyCode is not VK_UNDEFINED IllegalArgumentException - if source is null

===

java.​awt.​event.​KeyEvent
public KeyEvent(Component source, int id, long when, int modifiers, int keyCode, char keyChar, int keyLocation)