System.Xml.XmlBufferReader.GetInt64 C# (CSharp) Méthode

        public long GetInt64(int offset)
        {
            byte[] buffer = _buffer;
            byte b1, b2, b3, b4;
            b1 = buffer[offset + 0];
            b2 = buffer[offset + 1];
            b3 = buffer[offset + 2];
            b4 = buffer[offset + 3];
            Int64 lo = (UInt32)(((((b4 << 8) + b3) << 8) + b2) << 8) + b1;
            b1 = buffer[offset + 4];
            b2 = buffer[offset + 5];
            b3 = buffer[offset + 6];
            b4 = buffer[offset + 7];
            Int64 hi = (UInt32)(((((b4 << 8) + b3) << 8) + b2) << 8) + b1;
            return (hi << 32) + lo;
        }

 private long GetInt64()
 {
     DiagnosticUtility.DebugAssert(_type == ValueHandleType.Int64 || _type == ValueHandleType.TimeSpan || _type == ValueHandleType.DateTime, "");
     return(_bufferReader.GetInt64(_offset));
 }