.net - 使用FileStreamResult，如何关闭MemoryStream？

Question

以下代码有效，但是我想知道创建的MemoryStream是否正确关闭。应该如何执行此操作，或者FileStreamResult为我处理它？

public FileStreamResult DownloadBudgetedRoleOpportunities(
    Guid projectGuid, 
    IEnumerable<Guid> guidRequiredRoles)
{
    var rolebroker = new ProjectRoleBudgetBroker();
    var memstream = rolebroker.CreateBudgetedRoleOpportunies(
        projectGuid, 
        guidRequiredRoles);

    var fsr = new FileStreamResult ( memstream, "application/csv" )
              {
                FileDownloadName = "RoleOpportunities.csv"
              };
    // memstream.Close(); throws exception
    return fsr;
}

Answer 1

FileStreamResult将为您做到这一点。如有疑问，请始终检查代码，因为代码永远不会说谎，并且由于ASP.NET MVC是开源的，因此查看代码更加容易。

在Google上快速搜索FileStreamResult.cs，可让您验证WriteFile方法中的流是否已使用using语句正确处理。 (无双关语)

protected override void WriteFile(HttpResponseBase response) {
    // grab chunks of data and write to the output stream
    Stream outputStream = response.OutputStream;
    using (FileStream) {
        byte[] buffer = new byte[_bufferSize];

        while (true) {
            int bytesRead = FileStream.Read(buffer, 0, _bufferSize);
            if (bytesRead == 0) {
                // no more data
                break;
            }

            outputStream.Write(buffer, 0, bytesRead);
        }
    }
}