C#读取中文文件乱码的解方法

private void DetectEncoding()

{

    if (this.byteLen >= 2)

    {

        this._detectEncoding = false;

        bool flag = false;

        if ((this.byteBuffer[0] == 0xfe) && (this.byteBuffer[1] == 0xff))

        {

            this.encoding = new UnicodeEncoding(true, true);

            this.CompressBuffer(2);

            flag = true;

        }

        else if ((this.byteBuffer[0] == 0xff) && (this.byteBuffer[1] == 0xfe))

        {

            if (((this.byteLen < 4) || (this.byteBuffer[2] != 0)) || (this.byteBuffer[3] != 0))

            {

                this.encoding = new UnicodeEncoding(false, true);

                this.CompressBuffer(2);

                flag = true;

            }

            else

            {

                this.encoding = new UTF32Encoding(false, true);

                this.CompressBuffer(4);

                flag = true;

            }

        }

        else if (((this.byteLen >= 3) && (this.byteBuffer[0] == 0xef)) && ((this.byteBuffer[1] == 0xbb) && (this.byteBuffer[2] == 0xbf)))

        {

            this.encoding = Encoding.UTF8;

            this.CompressBuffer(3);

            flag = true;

        }

        else if ((((this.byteLen >= 4) && (this.byteBuffer[0] == 0)) && ((this.byteBuffer[1] == 0) && (this.byteBuffer[2] == 0xfe))) && (this.byteBuffer[3] == 0xff))

        {

            this.encoding = new UTF32Encoding(true, true);

            this.CompressBuffer(4);

            flag = true;

        }

        else if (this.byteLen == 2)

        {

            this._detectEncoding = true;

        }

        if (flag)

        {

            this.decoder = this.encoding.GetDecoder();

            this._maxCharsPerBuffer = this.encoding.GetMaxCharCount(this.byteBuffer.Length);

            this.charBuffer = new char[this._maxCharsPerBuffer];

        }

    }

}