mousetest2.java

关于java画图程序

import java.awt.Graphics;
import java.awt.Point;
import java.awt.Event;
import java.applet.Applet;
import java.awt.Color;
public class Mousetest2 extends Applet
{
	final int MaxMarks=40;
	int CurMarks=0;
	Point MarkStarts[]=new Point[MaxMarks];
	Point MarkEnds[]=new Point[MaxMarks];
	Point StartPoint,CurPoint;
	//String CurMessage="";
	
	public boolean mouseDown(Event evt,int x,int y){
	if(CurMarks<MaxMarks){
		StartPoint=new Point(x,y);
	}
	return true;
}
public boolean mouseUp(Event evt,int x,int y){
if(CurMarks<MaxMarks){
	MarkStarts[CurMarks]=StartPoint;
	MarkEnds[CurMarks]=CurPoint;
	CurMarks++;
	StartPoint=null;
	repaint();
}
return true;
}
public boolean mouseDrag(Event evt,int x,int y){
	if(CurMarks<MaxMarks){
		CurPoint=new Point(x,y);
		repaint();
	}
	return true;
}
public boolean mouseMove(Event evt,int x,int y){
	//CurMessage="鼠标的坐标位置为("+x+","+y+")";
repaint();
return true;
}
public void paint(Graphics g){
int x1,x2,y1,y2;
//g.drawString(CurMessage,10,10);
for(int i=0;i<CurMarks;i++){
x1=MarkStarts[ i].x;
y1=MarkStarts[ i].y;
x2=MarkEnds[ i].x;
y2=MarkEnds[ i].y;
g.setColor(Color.red);
g.drawLine(x1,y1,x2,y2);
}
if(StartPoint!=null){
	x1=StartPoint.x;
	y1=StartPoint.y;
	x2=CurPoint.x;
    y2=CurPoint.y;
    g.setColor(Color.red);
    g.drawLine(x1,y1,x2,y2);
}
}
}