爲什麼JavaScript XMLHttpRequest八位字節流MIME類型返回字符串的響應？

Question

我試圖獲得與XMLHttpRequest gltf二進制文件。這是我試過的代碼。

var xhr = new XMLHttpRequest(); 
xhr.open("GET","THE ADDRESS",true); 
xhr.setRequestHeader("Accept", "application/octet-stream"); 
xhr.responseType = "arraybuffer"; 
xhr.onload = function (v) { 
    resolve(xhr.response); // xhr.response must be ArrayBuffer but xhr.response is string 
}; 
xhr.onerror = function (e) { 
    reject(e); 
}; 
xhr.send(); 

如根據上面的代碼中，我肯定設置的responseType爲arraybuffer。但是，當負載處理程序調用時，responseType字段被更改爲""。

我沒有在這段代碼中調用任何其他``XMLHttpRequest。這是我得到的響應標題。

accept-ranges:bytes 
content-length:102040 
content-type:application/octet-stream 
date:Fri, 18 Nov 2016 09:30:13 GMT 
etag:"582ec3ef-18e98" 
last-modified:Fri, 18 Nov 2016 09:03:43 GMT 
server:h2o/2.0.4 
status:200 

而這是我發送的請求標題。

:authority:localhost 
:method:GET 
:path:/gex/t90-01/Duck/Duck.bin 
:scheme:https 
accept:*/* 
accept-encoding:gzip, deflate, sdch, br 
accept-language:ja,en-US;q=0.8,en;q=0.6 
cache-control:no-cache 
pragma:no-cache 
referer:https://localhost/gex/ 
user-agent:Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36 

Anyt help？

Answer 1

您可以通過如下更改setRequestHeader與overrideMimeType來嘗試下面的代碼。

而且，您應該在下面使用的resolve方法內正確處理xhr.response，並且不確定是否已正確完成。

var xhr = new XMLHttpRequest(); 
xhr.open("GET","THE ADDRESS",true); 
xhr.overrideMimeType("application/octet-stream"); 
//xhr.setRequestHeader("Accept", "application/octet-stream"); 
xhr.responseType = "arraybuffer"; 
xhr.onload = function (v) { 
    resolve(xhr.response); // xhr.response must be ArrayBuffer but xhr.response is string 
}; 
xhr.onerror = function (e) { 
    reject(e); 
}; 
xhr.send();