错误MouseMotionListener,MouseListener

时间:2011-11-19 22:33:50

标签: java swing mouseevent

我收到错误:

AniWorld is not abstract and does not override abstract method mouseMoved(MouseEvent) in MouseMotionListener
public class AniWorld extends  Applet implements MouseMotionListener, MouseListener

代码是:

 import java.awt.*;
import java.lang.*;
import java.applet.*;
import java.net.*;
import java.net.MalformedURLException;
import java.applet.Applet.*;
import java.io.IOException;
import java.awt.event.*;

public class AniWorld extends  Applet implements MouseMotionListener, MouseListener
{
public Stage      stage;
GridBagLayout     layout;
public void init()
{
    addMouseMotionListener(this);
    addMouseListener(this);
    setBackground( Color.white );
    layout = new GridBagLayout();
    setLayout( layout );
    int width = Integer.parseInt( getParameter( "width" ).trim() );
    int height = Integer.parseInt( getParameter( "height" ).trim() );
    stage = new Stage( width-10,height-10);
    constrain( stage,this,layout,1,0,1,6,
               GridBagConstraints.NONE,
               GridBagConstraints.CENTER,0,0 );

    stage.addBall();
    stage.addRect();
    stage.addArc();
    stage.start();
}
public void start()
{
    stage.start();
} // end of start()



public static void constrain(
                 Component     component,
                 Container     container,
                 GridBagLayout layout,
                 int           gridx,
                 int           gridy,
                 int           gridwidth,
                 int           gridheight,
                 int           fill,
                 int           anchor,
                 double        weightx,
                 double        weighty
                 ) {

    GridBagConstraints gbc = new GridBagConstraints();

    gbc.gridx      = gridx;
    gbc.gridy      = gridy;
    gbc.gridwidth  = gridwidth;
    gbc.gridheight = gridheight;
    gbc.fill       = fill;
    gbc.anchor     = anchor;
    gbc.weightx    = weightx;
    gbc.weighty    = weighty;

    layout.setConstraints( component,gbc );

    container.add( component );

    } // end of constrain()

public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
}

4 个答案:

答案 0 :(得分:2)

不让GUI类实现侦听器接口的另一个原因。最好的解决方案不是这样做,而是使用扩展MouseAdapter的匿名内部类或执行相同操作的私有内部类。否则,你要求你的GUI做得太多,并在将来为可能的调试问题做好准备。

答案 1 :(得分:1)

您需要添加

public void mouseMoved(MouseEvent) 

到AniWorld,或从已实现的接口列表中删除“MouseMotionListener”。

你得到这个错误的原因是因为当你说你实现一个接口时,你必须为接口中的所有方法提供实现,或者你的类需要是抽象的。

答案 2 :(得分:1)

您必须实施(或至少留下空白实施)方法MouseDragged(MouseEvent e)MouseMoved(MouseEvent e),因为您正在实施MouseMotionListener界面。

这里是MouseMotionListener

的文档

答案 3 :(得分:0)

是AniWorld,       你必须覆盖接口的所有方法,意味着如果你正在实现MouseListener,那么你必须覆盖所有五个方法,如果你要留下一个方法来覆盖那么100%你会得到同样的错误......你正在实现两个监听器,所以你必须覆盖,mouseCliked(),mouseEntered(),mouseExited(),mousePressed(),mouseReleased(),mouseDragged(),mouseMoved()

在所有方法覆盖后,您将成功,没有任何错误....