java - JNativeHook 将键写入文本区域

Question

当关键事件被记录时，它会打印到控制台。但不向文本区域添加任何文本。

我这里有一个框架:

public class A extends javax.swing.JFrame {

public A() {
    initComponents();
}


@SuppressWarnings("unchecked")                         
private void initComponents() {
 //code for components
}                     

private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {  
    try {
        GlobalScreen.registerNativeHook();
    }
    catch (NativeHookException ex) {
        System.err.println("There was a problem registering the native hook.");
        System.err.println(ex.getMessage());

        System.exit(1);
    }

    GlobalScreen.addNativeKeyListener(new GlobalKeyListenerExample());
    jTextArea1.append("logging started:\n");
}                                        
    }

    java.awt.EventQueue.invokeLater(new Runnable() {
        public void run() {
            new A().setVisible(true);
        }
    });
}

//calling this method when ever a keyevent is occured. but its not appending any text.
public void getTA(){
    jTextArea1.append("something was pressed");
}

// Variables declaration - do not modify                     
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JLabel jLabel1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTextArea jTextArea1;
// End of variables declaration                   
}

全局keylistener代码

public class GlobalKeyListenerExample implements NativeKeyListener {
A a;
public GlobalKeyListenerExample(){
  a = new A();
}

public void nativeKeyPressed(NativeKeyEvent e) {
    a.getTA();
    System.out.println("Key Pressed: " + NativeKeyEvent.getKeyText(e.getKeyCode()));
}

public void nativeKeyReleased(NativeKeyEvent e) {
    a.getTA();
    System.out.println("Key Pressed: " + NativeKeyEvent.getKeyText(e.getKeyCode()));
}

public void nativeKeyTyped(NativeKeyEvent e) {
    a.getTA();
    System.out.println("Key Typed: " + e.getKeyText(e.getKeyCode()));
}

}

当事件发生时调用 getTA() 但没有附加任何内容。任何帮助都会很棒。

Answer 1

正如我所说，您正在 GlobalKeyListenerExample 类中创建 A 类 的新对象。因此您有 2 个框架，一个是可见的，一个是隐藏的。

当您调用a.getTA();时，您正在调用从以下GlobalKeyListenerExample类创建的对象。因此您将文本设置为不可见框架的jtextfield

public  GlobalKeyListenerExample(){
  a = new A();//invisible frame
}

那么如何解决这个问题。一种方法是在您的类 A 中实现 NativeKeyListener，而不创建 GlobalKeyListener 类。这样您就可以像在 中那样实现所有抽象方法GlobalKeyListener 类。

并使用GlobalScreen.addNativeKeyListener(this);添加监听器。

示例

public class A extends javax.swing.JFrame implements NativeKeyListener {

    public A() {
        initComponents();
    }

    //implement abstract methods  
    @Override
    public void nativeKeyPressed(NativeKeyEvent e) {
        a.getTA();
        System.out.println("Key Pressed: " + NativeKeyEvent.getKeyText(e.getKeyCode()));
    }

    public void nativeKeyReleased(NativeKeyEvent e) {
        a.getTA();
        System.out.println("Key Pressed: " + NativeKeyEvent.getKeyText(e.getKeyCode()));
    }

    public void nativeKeyTyped(NativeKeyEvent e) {
        a.getTA();
        System.out.println("Key Typed: " + e.getKeyText(e.getKeyCode()));
    }

    private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
        try {
            GlobalScreen.registerNativeHook();
        } catch (NativeHookException ex) {
            System.err.println("There was a problem registering the native hook.");
            System.err.println(ex.getMessage());

            System.exit(1);
        }

        GlobalScreen.addNativeKeyListener(this);// add listner
        jTextArea1.append("logging started:\n");
    }

}

我无法测试此代码示例。如果您有任何问题，请询问。