正在处理StreamReader，该StreamReader读取范围外定义的流

在接受Stream参数的实用程序方法中，我依赖一些StreamReader来分析数据。

我不想关闭方法中的传入流。我想让调用者方法决定处理流。

不处理打开的StreamReader是否安全？我的意思是，它最终会被自动处理吗？它会导致内存泄漏吗？

这是我的实用方法。它的目标是读取流，并将其内容作为字符串返回，而不管数据是如何编码的：

    public static string GetStringAutoDetectEncoding(Stream data, out Encoding actualEncoding)
    {
        // 1. Is there a Bye Order Mask ?
        var candidateEncoding = DetectEncodingWithByteOrderMask(data);
        // 2a. No BOM, the data is either UTF8 no BOM or ANSI
        if (candidateEncoding == Encoding.Default)
        {
            var utf8NoBomEncoding = Encoding.GetEncoding("utf-8",new EncoderExceptionFallback(), new DecoderExceptionFallback());
            var positionBackup = data.Position;
            var sr = new StreamReader(data, utf8NoBomEncoding);
            try
            {
                // 3. Try as UTF8 With no BOM
                var result = sr.ReadToEnd(); // will throw error if not UTF8
                actualEncoding = utf8NoBomEncoding; // Probably an UTF8 no bom string
                return result;
            }
            catch (DecoderFallbackException)
            {
                // 4. Rewind the stream and fallback to ASNI
                data.Position = positionBackup;
                var srFallback = new StreamReader(data, candidateEncoding);
                actualEncoding = candidateEncoding;
                return srFallback.ReadToEnd(); ;
            }
        }
        // 2b. There is a BOM. Use the detected encoding
        else
        {
            var sr = new StreamReader(data, candidateEncoding);
            actualEncoding = candidateEncoding;
            return sr.ReadToEnd(); ;
        }
    }

然后，我可以在这样的一些方法：

void Foo(){
    using(var stream = File.OpenRead(@"c:'somefile")) {
        Encoding detected;
        var fileContent = MyUtilityClass.GetStringAutoDetectEncoding(stream, detected);
        Console.WriteLine("Detected encoding: {0}", encoding);
        Console.WriteLine("File content: {0}", fileContent);
    }
}

// This method will open the stream, execute the streamClosure, and then close the stream.
public static String StreamWork(Func<Stream, String> streamClosure) {
    // Set up the stream here.
    using (Stream stream = new MemoryStream()) { // Pretend the MemoryStream is your actual stream.
        // Execute the closure. Return it's results.
        return streamClosure(stream);
    }
}

public static void Main()
{
    // Wrap all of the work that needs to be done in a closure.
    // This represents all the work that needs to be done while the stream is open.
    Func<Stream, String> streamClosure = delegate(Stream stream) {
        using (StreamReader streamReader = new StreamReader(stream)) {
            return streamReader.ReadToEnd();
        }
    };
    // Call StreamWork. This method handles creating/closing the stream.
    String result = StreamWork(streamClosure);
    Console.WriteLine(result);
    Console.ReadLine();
}