PC端下载图片

PC端将图片下载到本地
saveFile(imgdata,filename){
    var save_link=document.createElementNS('http://www.w3.org/1999/xhtml', 'a');
    save_link.href=imgdata;
    save_link.download=filename;
    var event=document.createEvent('MouseEvents');
    event.initMouseEvent('click',true,false,window,0,0,0,0,0,false,false,false,false,0,null);
    save_link.dispatchEvent(event);
    this.confirmGoWeiXin = true;
  },