GetObjectAsync object stream couldn't use on the new FileStreamResult

I try use GetObjectAsync (Downloads an object as a stream.) and I would like to use stream on FileStreamResult. I can set it but when GetObjectAsync method finish my FileStreamResult.FileStream contentbytes go 0. You can follow the attaches. GetObjectAsync hasn’t a return type.

My old response and return value with S3.Model

            var file = await _storage.Download(bucket, key);

            var result  = new FileStreamResult(file.ResponseStream, file.Headers.ContentType)
            {
                FileDownloadName = temp.Name + type,
                LastModified = file.LastModified,
                EntityTag = new EntityTagHeaderValue(file.ETag)
            };

MinioClient

When I use with this code, i get that

ObjectDisposedException: Cannot access a closed Stream.

            using (Stream strm = new MemoryStream())
            {
                await _storage.Client1.GetObjectAsync(bucket, key, async stream => { await stream.CopyToAsync(strm); });
              
                fileStreamResult = new FileStreamResult(strm, file.Headers.ContentType)
                {
                    FileDownloadName = temp.Name + type,
                    LastModified = DateTimeOffset.Now,
                    EntityTag = new EntityTagHeaderValue(file.ETag)
                };     
           
                return fileStreamResult;
            }

then i try to it with this code,

           await _storage.Client1.GetObjectAsync(bucket, key, stream =>
           {
               fileStreamResult = new FileStreamResult(stream, file.Headers.ContentType)
               {
                   FileDownloadName = temp.Name + type,
                   LastModified = DateTimeOffset.Now,
                   EntityTag = new EntityTagHeaderValue(file.ETag)
               };
           });
            
            return fileStreamResult;

It sets to file stream and when finish the GetObjectAsync method, it set to fileStreamResult.FileStream contentBytes as 0 automaticly.

How i can fix this.

Thank you.

[ebozduman]

you can use stream.CopyToAsync(ms), but when minio calls back, the user response stream has ended, and the http channel has been closed.

@hyfree, The issue was with the async lambda function (Action<Stream>) used in GetObjectAsync callback. So, Func<Stream, CancellationToken, Task> support is added to properly await async methods, like Stream’s CopyToAsync.

@onurbos, @hyfree, Please follow PR#730, which is currently in the code review process. You can also check the functional test GetObject_AsyncCallback_Test1 in Minio.Functional.Tests/FunctionalTest.cs. The fix will be available as soon as the PR is merged and a new MinIO release is created for nuget.org. I anticipate it’ll be available in the next couple of weeks.

[harshavardhana]

Please upgrade to the latest release.