canvas实现平铺

 1 /**
 2  * Created by Administrator on 2016/1/30.
 3  */
 4 function draw(id){
 5     var canvas = document.getElementById(id);
 6     var context = canvas.getContext(‘2d‘);
 7     var img = new Image();
 8     img.src = "图像/1234.gif";
 9     img.onload = function (){
10         var ptrn = context.createPattern(img,‘no-repeat‘);
11         context.fillStyle = ptrn;
12         context.fillRect(0,0,300,200);
13     }
14 }