清华大学：JAVA教学课件：5-14

public void go(){
f = new Frame("Two listeners example");
f.add("North",new Label("Click and drag the mouse"));
tf = new TextField(30);
f.add("South",tf);

f.addMouseMotionListener(new MouseMotionAdapter(){
public void mouseDragged(MouseEvent e){
String s = "Mouse dragging,X=" +e.getX() +"Y="+ e.getY();
tf.setText(s);
}
}); // <- 注意括号在这里的用法

f.addMouseListener(new MouseEventHandler());
f.setSize(300,200);
f.setVisible(true);
}