C# multipart data uploading problems - InvalidOperationException

Asked Aug 08 '16 at 14:36

Active Aug 08 '16 at 14:47

Viewed 81 times

I have the problem with posting some files using MultipartFormDataContent. I try to use FileStream for adding file content to MultipartFormDataContent

var multipartMetadata = new MultipartFormDataContent();
var fileStream1 = File.Open("sample1.txt");
var fileStream2 = File.Open("sample2.txt");

multipartMetadata.Add(new StreamContent(fileStream1), fileData.Name, fileData.FileName);

multipartMetadata.Add(new StreamContent(fileStream2), fileData.Name, fileData.FileName);

var client = new HttpClient();

await client.PostAsync(uri, multipartMetadata);

InvalidOperationException was thrown during execution this code. Exception Message "Cannot close stream until all bytes are written". There are any ideas how to fix it ?

edited Aug 08 '16 at 14:47

asked Aug 08 '16 at 14:36

Виктор С

What was the exception message? – pquest Aug 08 '16 at 14:38
Exception message was "Cannot close stream until all bytes are written". – Виктор С Aug 08 '16 at 14:40
and what line does the exception occur on? – pquest Aug 08 '16 at 14:41
Related : http://stackoverflow.com/questions/16416601/c-sharp-httpclient-4-5-multipart-form-data-upload – Aug 08 '16 at 14:41
Exception occur on last line - client.PostAsync(uri, multipartMetadata) . – Виктор С Aug 08 '16 at 14:42
Related link provided above is not appropriate for me, because it uses MemoryStream. MemoryStream produces memory leaks for large files – Виктор С Aug 08 '16 at 14:43
can you show the code snippet where you create fileStream1 and fileStream2? – pquest Aug 08 '16 at 14:44
I create fileStream1/2 using simple way - var fileStream1 = File.OpenRead("sample1.txt"); var fileStream2 = File.OpenRead("sample2.txt"); – Виктор С Aug 08 '16 at 14:46
not in a using block or anything? – pquest Aug 08 '16 at 14:49
It shown without any blocks, but previously i tried to use blocks for streams, httpClient and MultipartFormDataContent. Exception are the same for different combinations. – Виктор С Aug 08 '16 at 14:52
if you put a breakpoint on `await client.PostAsync(uri, multipartMetadata);` and check the fileStream objects, are they open? – pquest Aug 08 '16 at 14:53
Or my god!!!! It is.... Sorry for this question. Problem has been resolved. – Виктор С Aug 08 '16 at 14:57
pquest, thank you very much! – Виктор С Aug 08 '16 at 14:58

C# multipart data uploading problems - InvalidOperationException

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