internal override void Update()
        {
            Length = IMM.ImmGetCompositionString(IMEHandle, Flag, IntPtr.Zero, 0);
            IntPtr pointer = Marshal.AllocHGlobal(Length);

            try
            {
                IMM.ImmGetCompositionString(IMEHandle, Flag, pointer, Length);
                _values = new byte[Length];
                Marshal.Copy(pointer, _values, 0, Length);
            }
            finally
            {
                Marshal.FreeHGlobal(pointer);
            }
        }
 internal override void Update()
 {
     Value = IMM.ImmGetCompositionString(IMEHandle, Flag, IntPtr.Zero, 0);
 }