请教各位大侠：如何讲两个点之间的线段去掉。

Question

用背景色再畫一邊就好了.
以白色為例:
g.setColor(Color.white) ;
g.drawLine(ax,ay,bx,by) ;ok,搞定,
請給分,謝謝

Answer 1

g.setBackgroundColor(透明颜色);
g.drawLine(int ax,int ay,int bx,int by);

Answer 2

sorry,可能是我说的不清楚，因为还有其他的图形，我只想把 a b 之间的线段去掉。谢谢！

Answer 3

我用
g.setColor(Color.white);
g.drawLine(ax,ay,bx,by) ;结果，图形全没了。不知是为什么？
一下是我的程序：import java.awt.*;
import javax.swing.*;
import java.io.*;
public class snowflakes1 extends JApplet
{
 int level=0;
 public void init()
 {
    String leveStr = JOptionPane.showInputDialog("enter the depth of recursion");
    level = Integer.parseInt(leveStr);
    } public void paint (Graphics g)
   {
    Point pointone= new Point(20,280);
    Point pointtwo = new Point(280,280);
    Point pointthree=new Point(150,20);    drawsnowflakes(g,level,pointone,pointtwo);
    drawsnowflakes(g,level,pointtwo,pointthree);
    drawsnowflakes(g,level,pointthree,pointone);    }    private void drawsnowflakes(Graphics g,int lev, Point p1,Point p2)        {
           Point exP1P2;
           Point exP2P3;
           Point exP3P1;           Point p4=new Point(p1.x+(p2.x-p1.x)/3,p1.y+(p2.y-p1.y)/3);
           Point p5=new Point(p1.x+2*(p2.x-p1.x)/3,p1.y+2*(p2.y-p1.y)/3);           if(lev>0)
           {
              exP1P2=exPoint(p1,p2);
              //exP2P3=exPoint(p2,p3);
              //exP3P1=exPoint(p3,p1);
              g.drawLine(p1.x,p1.y,p4.x,p4.y);
              g.drawLine(p4.x,p4.y,exP1P2.x,exP1P2.y);
              g.drawLine(exP1P2.x,exP1P2.y,p5.x,p5.y);
              g.drawLine(p5.x,p5.y,p2.x,p2.y);
              g.setColor(Color.white);   //?????????????????????????????
              g.drawLine(p4.x,p4.y,p5.x,p5.y);//?????????????????????????             drawsnowflakes(g,lev-1,p4,exP1P2);
             drawsnowflakes(g,lev-1,exP1P2,p5);
             drawsnowflakes(g,lev-1,p1,p4);
             drawsnowflakes(g,lev-1,p5,p2);          }
       }       private Point exPoint(Point pone, Point ptwo)      {         Point midpoint = new Point((int)((pone.x+ptwo.x)/2+(Math.pow(3.0,0.5)*(pone.y-ptwo.y)/6)),(int)((pone.y+ptwo.y)/2+(Math.pow(3.0,0.5)*(ptwo.x-pone.x)/6)));         return midpoint;         }  }

Answer 4

你用了
   g.setColor(Color.white);
   g.drawLine(p4.x,p4.y,p5.x,p5.y);
之後,把畫筆顏色還原才行阿
如果以前是黑色,應該再來句
      g.setColor(Color.black);