HTML5 Canvans(3) 调整Canvas画布大小和擦除

//得到2D渲染上下文
var cancans =
document.getElementById("myCanvas");

var
width = cancans.getAttribute("width");
var
height = cancans.getAttribute("height");
var
context = document.getElementById("myCanvas").getContext("2d");

var
x = 40, y = 40;
context.fillStyle =
"blue"; //设置填充色
context.fillRect(x, y, 55, 55);
  context.clearRect(x, y, 45, 45);

var
timeoutlRst;
var resizeCavans =
function ()
{
    //节流，防止频繁调用
   
clearTimeout(timeoutlRst);
    setTimeout(SetCanvansSize, 500);
}
var
SetCanvansSize = function () {
    var width =
document.body.clientWidth;
    var
height = $(window).get(0).innerHeight;//这里使用jquery的封装的方法得到高度
    cancans.width = width;
    cancans.height = height;
    context.fillStyle = "blue"; //设置填充色
   
context.fillRect(0, 0, width,
height);
}
window.onresize =
resizeCavans;
// cancans.setAttribute("width", 500);
//设置canvans大小后所有设置样式会重置

本文来自蓝猫一直飞的博客，原文地址:http://www.cnblogs.com/FlyCat/archive/2012/07/06/2579971.html