EPPlus cannot access a closed Stream

Question

Why does EPPlus throw `System.ObjectDisposedException: Cannot access a closed Stream.` after writing to a MemoryStream and seeking to position zero in an ASP.NET MVC application? ``` public FileStreamResult ExportToExcel() { using (var memoryStream = new MemoryStream()) using (var excel = new ExcelPackage()) { var worksheet = excel.Workbook.Worksheets.Add("Products"); worksheet.Cells["A1"].LoadFromCollection(Collection: myCollection, PrintHeaders: true); excel.SaveAs(memoryStream); memoryStream.Seek(0, SeekOrigin.Begin); // also tried memoryStream.Position = 0; return new FileStreamResult(memoryStream, contentType) { FileDownloadName = "test.xlsx", }; } } ``` If I move the `var memoryStream = ...` out of the `using` statement, it works, but it feels like this could leak a lot of memory for large results until the next garbage collection, if it is not disposed of explicitly. Maybe the ExcelPackage disposes the MemoryStream as well? Full Stack Trace: ``` [ObjectDisposedException: Cannot…

Accepted Answer

I think it is because you have your `MemoryStream` is a `using`.

This causes (at the end of processing) the stream to be closed and disposed.

Let the `FileStreamResult` handle closing this, and remove the `using`.

EPPlus cannot access a closed Stream

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