c# – 使用UTF-8解码文件流

有没有想过快速检查而没有以byte []的形式将整个文件读入内存的想法？

我正在使用VSTS 2008和C#.

当使用XMLDocument加载包含无效字节序列的XML文档时,会有一个异常,但是当将所有内容读入字节数组然后检查UTF-8时,没有异常,任何想法？

这是显示我的XML文件内容的屏幕截图,或者您可以从here下载该文件的副本

编辑1：

class Program
{
    public static byte[] RawReadingTest(string fileName)
    {
        byte[] buff = null;

        try
        {
            FileStream fs = new FileStream(fileName,FileMode.Open,FileAccess.Read);
            BinaryReader br = new BinaryReader(fs);
            long numBytes = new FileInfo(fileName).Length;
            buff = br.ReadBytes((int)numBytes);
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }

        return buff;
    }

    static void XMLTest()
    {
        try
        {
            XmlDocument xDoc = new XmlDocument();
            xDoc.Load("c:abc.xml");
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
    }

    static void Main()
    {
        try
        {
            XMLTest();
            Encoding ae = Encoding.GetEncoding("utf-8");
            string filename = "c:abc.xml";
            ae.GetString(RawReadingTest(filename));
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }

        return;
    }
}

编辑2：当使用新的UTF8Encoding(true,true)时会出现异常,但是当使用新的UTF8Encoding(false,true)时,不会抛出异常.我很困惑,因为它应该是控制是否抛出异常的第二个参数(如果有无效的字节序列),为什么第一个参数很重要？

public static void TestTextReader2()
    {
        try
        {
            // Create an instance of StreamReader to read from a file.
            // The using statement also closes the StreamReader.
            using (StreamReader sr = new StreamReader(
                "c:a.xml",new UTF8Encoding(true,true)
                ))
            {
                int bufferSize = 10 * 1024 * 1024; //could be anything
                char[] buffer = new char[bufferSize];
                // Read from the file until the end of the file is reached.
                int actualsize = sr.Read(buffer,bufferSize);
                while (actualsize > 0)
                {
                    actualsize = sr.Read(buffer,bufferSize);
                }
            }
        }
        catch (Exception e)
        {
            // Let the user know what went wrong.
            Console.WriteLine("The file could not be read:");
            Console.WriteLine(e.Message);
        }

    }