原生JS发请求

 var xhr = new XMLHttpRequest();
     xhr.onreadystatechange = function () {
         if (xhr.readyState == 4 && xhr.status == 200) {
            console.log(xhr.responseText);
         }
     };
    xhr.open('post', gDatagridUrl, true);
    xhr.setRequestHeader("Authorization", sessionStorage.getItem("token"));
    xhr.setRequestHeader("Content-Type", "application/json");
    xhr.setRequestHeader("Accept", "application/json");
    // xhr.onload = function () {
    //     if (this.status == 200) {
    //         var res = this.response;
    //         console.log(res)
    //     }
    // };
    xhr.send();