Java AWT鼠标事件全解析

要执行这些 Java AWT 程序，你需要将它们分别保存为独立的 .java 文件，并使用 javac 和 java 命令进行编译和运行。以下是每个程序的执行步骤和功能说明。

1.程序清单 1: `MouseEventsDemo.java`

此程序演示了鼠标事件处理，包括点击、进入、退出、按下、释放、拖动和移动事件。

java 复制代码

// 保存为 MouseEventsDemo.java
import java.awt.*;
import java.awt.event.*;

public class MouseEventsDemo extends Frame implements MouseListener, MouseMotionListener {

  String msg = "";
  int mouseX = 0, mouseY = 0; // 鼠标坐标 public MouseEventsDemo() {
     addMouseListener(this);
     addMouseMotionListener(this);
     addWindowListener(new MyWindowAdapter());
  }

  // 处理鼠标点击事件
  public void mouseClicked(MouseEvent me) {
    msg = msg + " -- click received";
    repaint();
  }

  // 处理鼠标进入组件区域事件 public void mouseEntered(MouseEvent me) {
    mouseX = 100;
    mouseY = 100;
    msg = "Mouse entered.";
    repaint();
  }

  // 处理鼠标离开组件区域事件
  public void mouseExited(MouseEvent me) {
    mouseX = 100;
    mouseY = 100;
    msg = "Mouse exited.";
    repaint();
  }

  // 处理鼠标按键按下事件
  public void mousePressed(MouseEvent me) {
    // 保存坐标 mouseX = me.getX();
    mouseY = me.getY();
    msg = "Button down";
    repaint();
  }

  // 处理鼠标按键释放事件 public void mouseReleased(MouseEvent me) {
    // 保存坐标
    mouseX = me.getX();
    mouseY = me.getY();
    msg = "Button Released";
    repaint();
  }

  // 处理鼠标拖动事件 public void mouseDragged(MouseEvent me) {
    // 保存坐标 mouseX = me.getX();
    mouseY = me.getY();
    msg = "*" + " mouse at " + mouseX + ", " + mouseY;
    repaint();
  }

  // 处理鼠标移动事件 public void mouseMoved(MouseEvent me) {
    msg = "Moving mouse at " + me.getX() + ", " + me.getY();
    repaint();
  }

  // 在窗口的当前 X,Y 位置显示消息
  public void paint(Graphics g) {
    g.drawString(msg, mouseX, mouseY);
  }

  public static void main(String[] args) {
    MouseEventsDemo appwin = new MouseEventsDemo();

    appwin.setSize(new Dimension(300, 300));
    appwin.setTitle("MouseEventDemo");
    appwin.setVisible(true);
  }
}

// 当点击框架中的关闭框时，关闭窗口并退出程序。
class MyWindowAdapter extends WindowAdapter {
  public void windowClosing(WindowEvent we) {
    System.exit(0);
  }
}

执行命令：

bash 复制代码

javac MouseEventsDemo.java
java MouseEventsDemo

2. 程序清单 2: `SimpleKey.java`

此程序演示了基本的键盘事件处理，包括按键按下、释放和键入事件。

java 复制代码

// 保存为 SimpleKey.java
import java.awt.*;
import java.awt.event.*;

public class SimpleKey extends Frame implements KeyListener {

  String msg = "";
  String keyState = "";

  public SimpleKey() {
    addKeyListener(this);
    addWindowListener(new MyWindowAdapter());
  }

  // 处理按键按下事件 public void keyPressed(KeyEvent ke) {
    keyState = "Key Down";
    repaint();
  }

  // 处理按键释放事件
  public void keyReleased(KeyEvent ke) {
    keyState = "Key Up";
    repaint();
  }

  // 处理键入字符事件 public void keyTyped(KeyEvent ke) {
    msg += ke.getKeyChar();
    repaint();
  }

  // 显示按键信息
  public void paint(Graphics g) {
    g.drawString(msg, 20, 100);
    g.drawString(keyState, 20, 50);
  }

  public static void main(String[] args) {
    SimpleKey appwin = new SimpleKey();

    appwin.setSize(new Dimension(200, 150));
    appwin.setTitle("SimpleKey");
    appwin.setVisible(true);
  }
}

// 当点击框架中的关闭框时，关闭窗口并退出程序。
class MyWindowAdapter extends WindowAdapter {
  public void windowClosing(WindowEvent we) {
    System.exit(0);
  }
}

执行命令：

bash 复制代码

javac SimpleKey.java
java SimpleKey

3. 程序清单 3: `KeyEventsDemo.java`

此程序演示了如何识别特定的虚拟键码（如功能键、方向键、翻页键）。

java 复制代码

// 保存为 KeyEventsDemo.java
import java.awt.*;
import java.awt.event.*;

public class KeyEventsDemo extends Frame
  implements KeyListener {

  String msg = "";
  String keyState = "";

  public KeyEventsDemo() {
    addKeyListener(this);
    addWindowListener(new MyWindowAdapter());
  }

  // 处理按键按下事件 public void keyPressed(KeyEvent ke) {
    keyState = "Key Down";

    int key = ke.getKeyCode();
    switch(key) {
      case KeyEvent.VK_F1:
        msg += "<F1>";
        break;
      case KeyEvent.VK_F2:
        msg += "<F2>";
        break;
      case KeyEvent.VK_F3:
        msg += "<F3>";
        break;
      case KeyEvent.VK_PAGE_DOWN:
        msg += "<PgDn>";
        break;
      case KeyEvent.VK_PAGE_UP:
        msg += "<PgUp>";
        break;
      case KeyEvent.VK_LEFT:
        msg += "<Left Arrow>";
        break;
      case KeyEvent.VK_RIGHT:
        msg += "<Right Arrow>";
        break;
    }

    repaint();
  }

  // 处理按键释放事件 public void keyReleased(KeyEvent ke) {
    keyState = "Key Up";
    repaint();
  }

  // 处理键入字符事件
  public void keyTyped(KeyEvent ke) {
    msg += ke.getKeyChar();
    repaint();
  }

  // 显示按键信息 public void paint(Graphics g) {
    g.drawString(msg, 20, 100);
    g.drawString(keyState, 20, 50);
  }

  public static void main(String[] args) {
    KeyEventsDemo appwin = new KeyEventsDemo();

    appwin.setSize(new Dimension(200, 150));
    appwin.setTitle("KeyEventsDemo");
    appwin.setVisible(true);
  }
}

// 当点击框架中的关闭框时，关闭窗口并退出程序。
class MyWindowAdapter extends WindowAdapter {
  public void windowClosing(WindowEvent we) {
    System.exit(0);
  }
}

执行命令：

bash 复制代码

javac KeyEventsDemo.java
java KeyEventsDemo

4. 程序清单 4: `AdapterDemo.java`

此程序演示了使用适配器类（MouseAdapter）来处理鼠标事件，避免了实现接口中所有方法的繁琐。

java 复制代码

// 保存为 AdapterDemo.java
import java.awt.*;
import java.awt.event.*;

public class AdapterDemo extends Frame {
  String msg = "";

  public AdapterDemo() {
     addMouseListener(new MyMouseAdapter(this));
     addMouseMotionListener(new MyMouseAdapter(this));
     addWindowListener(new MyWindowAdapter());
  }

  // 显示鼠标信息 public void paint(Graphics g) {
    g.drawString(msg, 20, 80);
  }

  public static void main(String[] args) {
    AdapterDemo appwin = new AdapterDemo();

    appwin.setSize(new Dimension(200, 150));
    appwin.setTitle("AdapterDemo");
    appwin.setVisible(true);
  }
}

// 仅处理鼠标点击和拖动事件
class MyMouseAdapter extends MouseAdapter {
  AdapterDemo adapterDemo;

  public MyMouseAdapter(AdapterDemo adapterDemo) {
    this.adapterDemo = adapterDemo;
  }

  // 处理鼠标点击事件
  public void mouseClicked(MouseEvent me) {
    adapterDemo.msg = "Mouse clicked";
    adapterDemo.repaint();
  }

  // 处理鼠标拖动事件
  public void mouseDragged(MouseEvent me) {
    adapterDemo.msg = "Mouse dragged";
    adapterDemo.repaint();
  }
}

// 当点击框架中的关闭框时，关闭窗口并退出程序。
class MyWindowAdapter extends WindowAdapter {
  public void windowClosing(WindowEvent we) {
    System.exit(0);
  }
}

执行命令：

bash 复制代码

javac AdapterDemo.java
java AdapterDemo

5. 程序清单 5: `MousePressedDemo.java`

此程序演示了使用外部适配器类处理鼠标按下事件。

java 复制代码

// 保存为 MousePressedDemo.java
import java.awt.*;
import java.awt.event.*;

public class MousePressedDemo extends Frame {
  String msg = "";

  public MousePressedDemo() {
    addMouseListener(new MyMouseAdapter(this));
    addWindowListener(new MyWindowAdapter());
  }

  public void paint(Graphics g) {
    g.drawString(msg, 20, 100);
  }

  public static void main(String[] args) {
    MousePressedDemo appwin = new MousePressedDemo();

    appwin.setSize(new Dimension(200, 150));
    appwin.setTitle("MousePressedDemo");
    appwin.setVisible(true);
  }
}

class MyMouseAdapter extends MouseAdapter {
  MousePressedDemo mousePressedDemo;

  public MyMouseAdapter(MousePressedDemo mousePressedDemo) {
    this.mousePressedDemo = mousePressedDemo;
  }

  // 处理鼠标按下事件 public void mousePressed(MouseEvent me) {
    mousePressedDemo.msg = "Mouse Pressed.";
    mousePressedDemo.repaint();
  }
}

// 当点击框架中的关闭框时，关闭窗口并退出程序。
class MyWindowAdapter extends WindowAdapter {
  public void windowClosing(WindowEvent we) {
    System.exit(0);
  }
}

执行命令：

bash 复制代码

javac MousePressedDemo.java
java MousePressedDemo

6. 程序清单 6: `InnerClassDemo.java`

此程序演示了使用内部类来处理事件，使代码结构更紧凑。

java 复制代码

// 保存为 InnerClassDemo.java
import java.awt.*;
import java.awt.event.*;

public class InnerClassDemo extends Frame {
  String msg = "";

  public InnerClassDemo() {
    addMouseListener(new MyMouseAdapter());
    addWindowListener(new MyWindowAdapter());
  }

  // 内部类处理鼠标按下事件
  class MyMouseAdapter extends MouseAdapter {
    public void mousePressed(MouseEvent me) {
      msg = "Mouse Pressed.";
      repaint();
    }
  }

  // 内部类处理窗口关闭事件
  class MyWindowAdapter extends WindowAdapter {
    public void windowClosing(WindowEvent we) {
      System.exit(0);
    }
  }

  public void paint(Graphics g) {
    g.drawString(msg, 20, 80);
  }

  public static void main(String[] args) {
    InnerClassDemo appwin = new InnerClassDemo();

    appwin.setSize(new Dimension(200, 150));
    appwin.setTitle("InnerClassDemo");
    appwin.setVisible(true);
  }
}

执行命令：

bash 复制代码

javac InnerClassDemo.java
java InnerClassDemo

7. 程序清单 7: `AnonymousInnerClassDemo.java`

此程序演示了使用匿名内部类来处理事件，这是最简洁的事件处理方式。

java 复制代码

// 保存为 AnonymousInnerClassDemo.java
import java.awt.*;
import java.awt.event.*;

public class AnonymousInnerClassDemo extends Frame {
  String msg = "";

  public AnonymousInnerClassDemo() {

    // 匿名内部类处理鼠标按下事件
    addMouseListener(new MouseAdapter() {
      public void mousePressed(MouseEvent me) {
        msg = "Mouse Pressed.";
        repaint();
      }
    });

 // 匿名内部类处理窗口关闭事件
    addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent we) {
        System.exit(0);
      }
    });
  }

  public void paint(Graphics g) {
    g.drawString(msg, 20, 80);
  }

  public static void main(String[] args) {
    AnonymousInnerClassDemo appwin =
                  new AnonymousInnerClassDemo();

    appwin.setSize(new Dimension(200, 150));
    appwin.setTitle("AnonymousInnerClassDemo");
    appwin.setVisible(true);
  }
}

执行命令：

bash 复制代码

javac AnonymousInnerClassDemo.java
java AnonymousInnerClassDemo

程序功能与事件处理机制总结

程序文件	核心演示内容	事件处理方式	关键接口/类
`MouseEventsDemo`	鼠标所有事件（点击、移动、拖动等）	主类实现 `MouseListener` 和 `MouseMotionListener` 接口	`MouseListener`, `MouseMotionListener`
`SimpleKey`	键盘基本事件（按下、释放、键入）	主类实现 `KeyListener` 接口	`KeyListener`
`KeyEventsDemo`	识别特定虚拟键码（如F1, 方向键）	主类实现 `KeyListener` 接口，使用 `getKeyCode()`	`KeyListener`, `KeyEvent.VK_*`
`AdapterDemo`	使用适配器类处理鼠标事件	使用外部 `MouseAdapter` 类	`MouseAdapter`
`MousePressedDemo`	使用外部适配器类处理单一事件	使用外部 `MouseAdapter` 类	`MouseAdapter`
`InnerClassDemo`	使用内部类处理事件	使用成员内部类	内部类
`AnonymousInnerClassDemo`	使用匿名内部类处理事件	使用匿名内部类	匿名内部类

通用执行步骤：

保存文件 ：将每个 listing 的代码复制到对应的 .java 文件中（例如 MouseEventsDemo.java）。
编译：在命令行中，导航到文件所在目录，运行 javac 文件名.java。
运行：编译成功后，运行 java 类名（注意：类名不含 .java 后缀）。

注意事项：

这些是基于 AWT 的旧式 Java GUI 程序。运行前请确保已安装 Java开发工具包 (JDK)。
程序窗口的关闭功能均通过 WindowAdapter 实现，点击窗口关闭按钮可退出程序。
所有程序都遵循 AWT 的事件处理模型：事件源 （如 Frame）注册事件监听器 （如 MouseListener），当事件发生时，会调用监听器对应的回调方法（如 mouseClicked）。

Java AWT鼠标事件全解析

1.程序清单 1: MouseEventsDemo.java

2. 程序清单 2: SimpleKey.java

3. 程序清单 3: KeyEventsDemo.java

4. 程序清单 4: AdapterDemo.java

5. 程序清单 5: MousePressedDemo.java

6. 程序清单 6: InnerClassDemo.java

7. 程序清单 7: AnonymousInnerClassDemo.java

程序功能与事件处理机制总结

参考来源

1.程序清单 1: `MouseEventsDemo.java`

2. 程序清单 2: `SimpleKey.java`

3. 程序清单 3: `KeyEventsDemo.java`

4. 程序清单 4: `AdapterDemo.java`

5. 程序清单 5: `MousePressedDemo.java`

6. 程序清单 6: `InnerClassDemo.java`

7. 程序清单 7: `AnonymousInnerClassDemo.java`