canvas转存为图片实例教程

<canvas id="canvas"></canvas>
<button class="button-balanced" id="save">save</button>
<br />
<a href="" download="canvas_love.png" id="save_href">
 <img src="" id="save_img"/>
</a>

var c=document.getElementById("canvas");
function drawLove(canvas){
 let ctx = canvas.getContext("2d");
 ctx.beginPath();
 ctx.fillStyle="#E992B9";
 ctx.moveTo(75,40);
 ctx.bezierCurveTo(75,37,70,25,50,25);
 ctx.bezierCurveTo(20,25,20,62.5,20,62.5);
 ctx.bezierCurveTo(20,80,40,102,75,120);
 ctx.bezierCurveTo(110,102,130,80,130,62.5);
 ctx.bezierCurveTo(130,62.5,130,25,100,25);
 ctx.bezierCurveTo(85,25,75,37,75,40);
 ctx.fill();
}
drawLove(c); 

var butSave = document.getElementById("save");
butSave.onclick=function(){
 var svaeHref = document.getElementById("save_href");
 /*
 * 传入对应想要保存的图片格式的mime类型
 * 常见：image/png，image/gif,image/jpg,image/jpeg
 */
 var img = document.getElementById("save_img");
 var tempSrc = canvas.toDataURL("image/png");
 svaeHref.href=tempSrc; 
 img.src=tempSrc; 
};