用java语言编写的简单画线程序，部分源码 import java.awt.*; import java.awt.event.*; public class MyMouseDraw1P extends WindowAdapter{ Frame win; MyCanvas c; int x,y; public MyMouseDraw1P(){ win = new Frame(); x=-1; y=-1; c = new MyCanvas(); win.setLayout(new BorderLayout(0,0)); win.add(c, BorderLayo