问FileReader readAsDataURL()方法无法读取typescript中24 MB的大型pdf文件

EN

var config = { headers: { 'Content-Type': undefined } };

$http.post(url, file, config)
  .then(function (response) {
    var data = response.data;
    var status = response.status;
    var statusText = response.statusText;
    var headers = response.headers;
    var config = response.config;

    console.log("Success");
    return response; 
}).catch(function (errorResponse)
    console.log("Error");
    throw errorResponse;
});