System.IO.UnmanagedMemoryStream.SetLength C# (CSharp) Méthode

        public override void SetLength(long value)
        {
            if (value < 0)
                throw new ArgumentOutOfRangeException("length", SR.ArgumentOutOfRange_NeedNonNegNum);
            Contract.EndContractBlock();
            if (!_isOpen) throw new ObjectDisposedException(null, SR.ObjectDisposed_StreamClosed);
            if (!CanWrite) throw new NotSupportedException(SR.NotSupported_UnwritableStream);

            if (value > _capacity)
                throw new IOException(SR.IO_FixedCapacity);

            long pos = Interlocked.Read(ref _position);
            long len = Interlocked.Read(ref _length);
            if (value > len)
            {
                unsafe
                {
                    Helpers.ZeroMemory(_mem + len, value - len);
                }
            }
            Interlocked.Exchange(ref _length, value);
            if (pos > value)
            {
                Interlocked.Exchange(ref _position, value);
            }
        }

		public void SetLength_Negative ()
		{
			UnmanagedMemoryStream ums = new UnmanagedMemoryStream(mem_byteptr,
				length, capacity, FileAccess.ReadWrite);
			try {
				ums.SetLength(-1);
				Assert.Fail ("#1");
			} catch (ArgumentOutOfRangeException ex) {
				// Non-negative number required
				Assert.AreEqual (typeof (ArgumentOutOfRangeException), ex.GetType (), "#2");
				Assert.IsNull (ex.InnerException, "#3");
				Assert.IsNotNull (ex.Message, "#4");
				Assert.IsNotNull (ex.ParamName, "#5");
				Assert.AreEqual ("length", ex.ParamName, "#6");
			}
			ums.Close();
		}