浏览器下载img标签Base64图片

https://blog.csdn.net/qq_42076140/article/details/82113622    原文地址

<a href="javascript:download();" >点击下载图片</a>

 //下载图片
function  download() {
     var imgdata =  $("#showpaypic").prop('src');//这里放需要下载的base64
    downloadfile(new date().gettime()+".png", imgdata);
 }
 //下载
 function downloadfile(filename, content) {
     var alink = document.createelement('a');
     var blob = this.base64toblob(content); //new blob([content]);
     var evt = document.createevent("htmlevents");
     evt.initevent("click", true, true);//initevent 不加后两个参数在ff下会报错  事件类型，是否冒泡，是否阻止浏览器的默认行为
     alink.download = filename;
     alink.href = url.createobjecturl(blob);
     // alink.dispatchevent(evt);
     alink.click()
 }
 //base64转blob
 function base64toblob(code) {
     var parts = code.split(';base64,');
     var contenttype = parts[0].split(':')[1];
     var raw = window.atob(parts[1]);
     var rawlength = raw.length;

     var uint8array = new uint8array(rawlength);

     for (var i = 0; i < rawlength; ++i) {
         uint8array[i] = raw.charcodeat(i);
     }
     return new blob([uint8array], {type: contenttype});
 }