Java 使用空格键触发JButton,或输入key,或单击鼠标
我试图获得一个简单的JFrame,其中有一个按钮可以在这些事件发生时触发事件:Java 使用空格键触发JButton,或输入key,或单击鼠标,java,swing,jbutton,key-events,Java,Swing,Jbutton,Key Events,我试图获得一个简单的JFrame,其中有一个按钮可以在这些事件发生时触发事件: 按下Enter键,JButton具有焦点 按下空格键,JButton具有焦点 单击JButton 似乎Enter和空格键是“免费”的,同时在JButton上使用addActionListener进行默认的鼠标单击;问题是,我读到密钥绑定依赖于使用的外观 我试图通过向JButton的动作图中添加Enter和Spacebar来获得LaF中的通用行为,甚至还添加了一个随机键(“m”),以确保动作图正在执行(它是),但现
- 按下Enter键,JButton具有焦点
- 按下空格键,JButton具有焦点
- 单击JButton
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.InputMap;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
import javax.swing.UIManager;
public class Example extends JFrame {
// ============================
private class BtnListener extends AbstractAction {
private static final long serialVersionUID = 1L;
public void actionPerformed(ActionEvent ae) {
System.out.println("\nclick button listener triggered");
System.out.println(ae.getSource().getClass().toString());
}
} // class BtnListener
private static final int NO_MODIFIER = 0;
private static final boolean ON_KEY_PRESS = false;
private static final KeyStroke ENTER_PRESSED = KeyStroke.getKeyStroke(
KeyEvent.VK_ENTER, NO_MODIFIER, ON_KEY_PRESS);
private static final KeyStroke M_PRESSED = KeyStroke.getKeyStroke(
KeyEvent.VK_M, NO_MODIFIER, ON_KEY_PRESS);
private static final KeyStroke SPACEBAR_PRESSED = KeyStroke.getKeyStroke(
KeyEvent.VK_SPACE, NO_MODIFIER, ON_KEY_PRESS);
private JButton btnButton;
private final AbstractAction btnListener = new BtnListener();
private JPanel buttonPanel;
private JFrame frmMain;
public static void main(String[] args) {
Example ex = new Example();
ex.displayFrame();
}
Action btnActionListener = new AbstractAction() {
private static final long serialVersionUID = 1L;
public void actionPerformed(ActionEvent e) {
System.out.println("\nkey button action triggerred");
System.out.println(e.getSource().getClass().toString());
if (e.getSource() instanceof JButton) {
System.out.println("button");
} else {
System.out.println("Something else");
}
}
};
public Example() {
initialize();
}
public void displayFrame() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Throwable e) {
e.printStackTrace();
}
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
frmMain.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
private void initialize() {
frmMain = new JFrame();
btnButton = new JButton("Abutton");
// Comment this out, you lose the mouse click
btnButton.addActionListener(btnListener);
// Comment out ActionMaps, but keep addActionListner (above), and
// only lose M_PRESSED
InputMap buttonFocusedMap = btnButton
.getInputMap(JComponent.WHEN_FOCUSED);
buttonFocusedMap.put(ENTER_PRESSED, "blah");
btnButton.getActionMap().put("blah", btnActionListener);
buttonFocusedMap.put(SPACEBAR_PRESSED, "blort");
btnButton.getActionMap().put("blort", btnActionListener);
buttonFocusedMap.put(M_PRESSED, "gaaak");
btnButton.getActionMap().put("gaaak", btnActionListener);
// Is there a way to add a mouse click to the ActionMap?
buttonPanel = new JPanel();
buttonPanel.add(btnButton);
frmMain.getContentPane().add(buttonPanel);
frmMain.setBounds(100, 100, 500, 432);
frmMain.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
您可以(也可能应该)做的是创建一个抽象动作。您可以将AbstractAction用于ActionMap和单击(do JButton.setAction(…)
BasicButtonListener
,由BasicButtonUI
使用,确保所有按钮(选中、单选、切换)在聚焦时都绑定到空格。这可以跨平台工作,即使单个外观可能会唯一地呈现各种按钮模型状态。按空格键可调用按下的ui动作
,释放空格键可调用已释放的ui动作
。当鼠标在按钮的边界内按下和释放时,也会发生同样的情况;按住按钮的同时将其拖到按钮外部,以查看启用状态的更改
在任何一种情况下,按下和释放的组合都会调用按钮的actionPerformed()
方法
将Enter绑定到
操作
的一种方便方法是通过根窗格的方法,而不考虑焦点。这说明了单击按钮的所有三种方式。非常好!谢谢你的深刻解释。