コード例 #1
0
        /// <summary>
        /// Reads a sequence of bytes from the current stream and advances the position within the stream by the number of bytes read
        /// </summary>
        /// <param name="buffer">An array of bytes. When this method returns, the buffer contains the specified byte array with the values between offset and (offset + count - 1) replaced by the bytes read from the current source.</param>
        /// <param name="offset">The zero-based byte offset in buffer at which to begin storing the data read from the current stream.</param>
        /// <param name="count">The maximum number of bytes to be read from the current stream.</param>
        /// <returns>The total number of bytes read into the buffer. This can be less than the number of bytes requested if that many bytes are not currently available, or zero (0) if the end of the stream has been reached.</returns>
        /// <exception cref="System.ArgumentException"/>
        /// <exception cref="System.ArgumentNullException"/>
        /// <exception cref="System.OutOfMemoryException"/>
        public int Read(byte[] buffer, int offset, int count)
        {
            if (buffer != null)
            {
                if (offset + count <= buffer.Length)
                {
                    lock (sound)
                    {
                        Stop();

                        IntPtr bufferHandle = IntPtr.Zero;
                        bufferHandle = Marshal.AllocHGlobal(count);

                        int bytesRead = Convert.ToInt32(sound.Read(bufferHandle, (uint)count));

                        if (bufferHandle != IntPtr.Zero && bytesRead > 0)
                        {
                            byte[] data = new byte[bytesRead];
                            Marshal.PtrToStructure(bufferHandle, data);
                            Array.Copy(data, 0, buffer, offset, bytesRead);
                            Marshal.FreeHGlobal(bufferHandle);
                            return(bytesRead);
                        }
                        else
                        {
                            return(0);
                        }
                    }
                }
                else
                {
                    throw new ArgumentException("The sum of offset and count is larger than the buffer length.");
                }
            }
            else
            {
                throw new ArgumentNullException("buffer");
            }
        }