function print_voucher(){ // 打印的主要方法
var win=window.open();
win.document.write("<br><img src=‘"+canvas.toDataURL()+"‘/>");
win.print();
win.location.reload();
}
需要打开一个窗口进行打印，示例代码如下：
<script>
$(function(){
var canvas=document.getElementById("canvas");
var ctx=canvas.getContext("2d");
ctx.fillStyle="gold";
ctx.strokeStyle="blue";
ctx.lineWidth=5;
ctx.rect(50,50,100,100);
ctx.fill();
ctx.stroke();
function print_voucher(){
var win=window.open();
win.document.write("<br><img src=‘"+canvas.toDataURL()+"‘/>");
win.print();
win.location.reload();
}
$("#printVoucher").click(function(){ print_voucher(); });
}); // end $(function(){});
</script>
<body>
<canvas id="canvas" width=300 height=300></canvas><br>
<button id="printVoucher">Print</button>
</body>
原文：http://www.cnblogs.com/LLSutdy/p/6751886.html