使用js实现雪花飘落效果_javascript技巧

 
  <script><br><br> function start(){<br><br> var array=new Array();<br><br> var canvas=document.getElementById("mycanvas");<br><br> var context=canvas.getContext("2d");<br><br> for(var i=0;i<50;i++){<br><br> var Showsnow=new showsnow();<br><br> array.push(Showsnow);<br><br> }<br><br> <BR> time=setInterval(function (){<br><br> context.clearRect(0,0,canvas.width,canvas.height);<BR> for(var i=0;i<array.length;i++){<br><br> <BR> array[i].move();<BR> array[i].draw(context);<br><br> }<br><br> },500);<br><br> }<BR> function showsnow(){<BR> var y=parseInt(Math.random()*50)*10;<br><br> var x=parseInt(Math.random()*80)*10;<br><br> this.draw=function(context){<br><br> <BR> context.font="50px Calibri";<BR> context.fillText("*",x,y);<br><br> <BR> }<BR> this.move=function(){<BR> y+=20;<br><br> if(y>600){<BR> y=0;<BR> }<BR> }<BR> }<BR> </script>