[PHP知识库]PHP之 将canvas生成的饼状图生成图片

参考
https://blog.csdn.net/wxw_nini/article/details/82463749
https://blog.csdn.net/Byte_Dance/article/details/87866929

js中

$("#btn").click(function () {
     var sr = document.getElementById("ccc");
     html2canvas(sr).then(function (canvas) {
         window.html_canvas = canvas.toDataURL("image/png").replace("image/png", "image/octet-stream");
         var pHtml = "<img src="+window.html_canvas+" id='image_down'/>";
         $('#html2canvas').html(pHtml);
         // $('.ask_con').remove();
         ceshi(window.html_canvas);
     });
 })

 /**
  * 把图片文件流保存到本地
  */
 function ceshi(path){
     $.ajax({
         url:"{:url('admin/download/img')}",
         data:{img:path},
         type:'post',
         dataType:'json',
         success:function(res){
             if(res.code == 200){
                 layer.msg('下载图片成功');

                 const url="http://dmp.51jcloud.com/"+res.data;
                 fetch(url).then(async res => await res.blob()).then((blob) => {
                   // 创建隐藏的可下载链接
                   const a = document.createElement('a');
                   a.style.display = 'none';
                   a.href = URL.createObjectURL(blob);
                   // 保存下来的文件名
             //    a.download = 'image.png';
                   a.download = res.name;
                   document.body.appendChild(a);
                   a.click();
                   // 移除元素
                   document.body.removeChild(a);
                 })  

             }else{
                 layer.msg('下载图片失败');
             }
         }
     });
 }

控制器

public function chart_img(){
    $base64_string = $this->request->param('img');

    $base64_string= explode(',', $base64_string); //截取data:image/png;base64, 这个逗号后的字符
    $data= base64_decode($base64_string[1]);//对截取后的字符使用base64_decode进行解码
    $url = ROOT_PATH . 'public' . DS . 'uploads' . DS . 'images' . DS .time().rand(1000,9999).".png";
    $res = file_put_contents($url, $data); //写入文件并保存到本地
    
    $u = explode('/',$url);
    $name = $u[7];
    $downurl = 'uploads' . DS . 'images' . DS .$u[7];

    if($res){
        $da = [
            'code'=>200,
            // 'data'=>$url,
            'data'=>$downurl,
            'name'=>$name
        ];
    }else{
         $da = [
            'code'=>403
        ];
    }
    return $da;
}