title: How to disable base64-encoded filenames in HttpClient/MultipartFormDataContent
body: <p>I'm using <code>HttpClient</code> to POST <code>MultipartFormDataContent</code> to a Java web application. I'm uploading several <code>StringContents</code> and one file which I add as a <code>StreamContent</code> using <code>MultipartFormDataContent.Add(HttpContent content, String name, String fileName)</code> using the method <code>HttpClient.PostAsync(String, HttpContent)</code>.</p>
  
  <p>This works fine, except when I provide a <strong>fileName</strong> that contains german umlauts (I haven't tested other non-ASCII characters yet). In this case, <strong>fileName</strong> is being base64-encoded. The result for a file named <strong>99 2 LD 353 Temp Äüöß-1.txt</strong> </p>
  
  <p>looks like this:</p>
  
  <pre><code> __utf-8_B_VGVtcCDvv73vv73vv73vv71cOTkgMiBMRCAzNTMgVGVtcCDvv73vv73vv73vv70tMS50eHQ___
  </code></pre>
  
  <p>The Java server shows this encoded file name in its UI, which confuses the users. I cannot make any server-side changes.</p>
  
  <p>How do I disable this behavior? Any help would be highly appreciated.</p>
  
  <p>Thanks in advance!</p>