点评：将HTML5 Canvas的内容保存为图片主要思想是借助Canvas自己的API - toDataURL()来实现，具体实现如下，感兴趣的朋友可以参考下哈，希望对你有所帮助
主要思想是借助Canvas自己的API - toDataURL()来实现，整个实现HTML + JavaScript的代码很简单。
<html>
<meta http-equiv="X-UA-Compatible" content="chrome=1">
<head>
<script>
window.onload = function() {
draw();
var saveButton = document.getElementById("saveImageBtn");
bindButtonEvent(saveButton, "click", saveImageInfo);
var dlButton = document.getElementById("downloadImageBtn");
bindButtonEvent(dlButton, "click", saveAsLocalImage);
};
function draw(){
var canvas = document.getElementById("thecanvas");
var ctx = canvas.getContext("2d");
ctx.fillStyle = "rgba(125, 46, 138, 0.5)";
ctx.fillRect(25,25,100,100);
ctx.fillStyle = "rgba( 0, 146, 38, 0.5)";
ctx.fillRect(58, 74, 125, 100);
ctx.fillStyle = "rgba( 0, 0, 0, 1)"; // black color
ctx.fillText("Gloomyfish - Demo", 50, 50);
}
function bindButtonEvent(element, type, handler)
{
if(element.addEventListener) {
element.addEventListener(type, handler, false);
} else {
element.attachEvent('on'+type, handler);
}
}
function saveImageInfo ()
{
var mycanvas = document.getElementById("thecanvas");
var image = mycanvas.toDataURL("image/png");
var w=window.open('about:blank','image from canvas');
w.document.write("<img src='"+image+"' />