资 源 简 介
应用背景 var canvas=document.getElementById("demo");
var cxt=canvas.getContext("2d");
var flag=0;
canvas.onmousedown=function(evt){
evt=window.event?window.event:evt;
var startX=evt.pageX-this.offsetLeft;
var startY=evt.pageY-this.offsetTop;
cxt.beginPath();
cxt.moveTo(startX,startY);
flag=1;
}
//鼠标移动 (获取鼠标位置)
canvas.onmousemove=function(){