begin end invoke problem

        [TestMethod]
        public void BeginEndPairWithData()
        {
            byte[] changingData = new byte[] { 0 };
            Action changeData = () => changingData = new byte[] { 1 };
            IAsyncResult res = changeData.BeginInvoke(changeData.EndInvoke, null);
            res.AsyncWaitHandle.WaitOne();
            changingData.ShouldAllBeEquivalentTo((byte)1);
        }

        [TestMethod]
        public void BeginEndPairWithDataInSeparateMethods()
        {
            byte[] changingData = new byte[] { 0 };
            IAsyncResult res = BeginChange(ref changingData, EndChange);
            res.AsyncWaitHandle.WaitOne();
            changingData.ShouldAllBeEquivalentTo((byte)1);
        }

        private void EndChange(IAsyncResult res)
        {
        }

        private IAsyncResult BeginChange(ref byte[] changingData, AsyncCallback callback)
        {
            Action changeData = () => changingData = new byte[] { 1 }; // <-- problem here Can't change changingData in lambda
            return changeData.BeginInvoke(callback, null);
        }