以编程方式触发JTextField中的键事件？ [英] Programmatically trigger a key events in a JTextField?

问题描述

如何以编程方式触发正在 ENTER 上侦听事件的 JTextField 上的按键事件？

How do I programmatically trigger a key pressed event on a JTextField that is listening for events on the ENTER?

我的 JTextField 上的关键事件的监听器声明如下：

The listener for key events on my JTextField is declared as follows:

myTextField.addKeyListener(new KeyAdapter() {

    @Override
    public void keyTyped(KeyEvent e) {
        if (e.getKeyChar() == KeyEvent.VK_ENTER) {
            // Do stuff
        }
    }
});

谢谢。

推荐答案

• 不要在 JTextField 上使用 KeyListener 添加 ActionListener 将在按下 ENTER 时触发（感谢@robin +1获取建议）

  • Do not use KeyListener on JTextField simply add ActionListener which will be triggered when ENTER is pressed (thank you @robin +1 for advice)

    JTextField textField = new JTextField();
    
    textField.addActionListener(new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent ae) {
             //do stuff here when enter pressed
        }
    });
    

  
  

  • 要触发 KeyEvent 使用 requestFocusInWindow（）关于组件并使用 Robot 类来模拟按键

  • To trigger KeyEvent use requestFocusInWindow() on component and use Robot class to simulate key press

    如下所示：

    textField.requestFocusInWindow();
    
    try { 
        Robot robot = new Robot(); 
    
        robot.keyPress(KeyEvent.VK_ENTER); 
    } catch (AWTException e) { 
    e.printStackTrace(); 
    } 
    

    示例：

    import java.awt.AWTException;
    import java.awt.Robot;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    import java.awt.event.KeyEvent;
    import javax.swing.JFrame;
    import javax.swing.JTextField;
    import javax.swing.SwingUtilities;
    
    public class Test {
    
        public static void main(String[] args) {
            SwingUtilities.invokeLater(new Runnable() {
                @Override
                public void run() {
                    JFrame frame = new JFrame();
                    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                    JTextField textField = new JTextField();
    
                    textField.addActionListener(new ActionListener() {
                        @Override
                        public void actionPerformed(ActionEvent ae) {
                            System.out.println("Here..");
                        }
                    });
                    frame.add(textField);
    
                    frame.pack();
                    frame.setVisible(true);
    
                    textField.requestFocusInWindow();
    
                    try {
                        Robot robot = new Robot();
    
                        robot.keyPress(KeyEvent.VK_ENTER);
                    } catch (AWTException e) {
                        e.printStackTrace();
                    }
                }
            });
        }
    }
    

    更新：

    像@Robin和@mKorbel这样的人建议您可能需要 DocumentListener / DocumentFiler （过滤器允许在 JTextField 更新之前进行验证。）

    As others like @Robin and @mKorbel have suggested you might want a DocumentListener/DocumentFiler (Filter allows validation before JTextField is updated).

    你需要在数据验证事件IMO。

    You will need this in the event of data validation IMO.

    看到类似的问题 here

    它显示了如何将 DocumentFilter 添加到 JTextField 进行数据验证。文件过滤的原因就像我说的那样，在显示chnage之前允许验证更有用IMO

    it shows how to add a DocumentFilter to a JTextField for data validation. The reason for document filter is as I said allows validation before chnage is shown which is more useful IMO

    这篇关于以编程方式触发JTextField中的键事件？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！