c# - Condition false, but code inside the if statement executed

Question

I have the following method:

public bool ConnectAsync()
{
    if (IsConnected)
        throw new InvalidOperationException("Socket is already connected");

    if (IsConnecting)
    {
        throw new InvalidOperationException("Attempt to connect in progress");
    }

    . . .
}

Where:

    private readonly object padLock = new object();

    private bool isConnecting = false;

    public bool IsConnected
    {
        get
        {
            lock (padLock)
            { return socket.Connected; }
        }
    }

    public bool IsConnecting
    {
        get
        {
            lock (padLock)
            { return isConnecting; }
        }

        private set
        {
            lock (padLock)
            { isConnecting = value; }
        }
    }

Why the code inside the if statement is executed if my variable isConnecting is false?

Edit:
If I use the filed isConnecting instead of the property IsConnecting I have the same behavior. The code runs in the same thread anywhere.

Edit 2:

Finally this works:

lock (padLock)
{
    if (IsConnecting)
        throw new InvalidOperationException("Attempt to connect in progress");
}

And this works:

{
    if (IsConnecting)
        throw new InvalidOperationException("Attempt to connect in progress");
}

But why?

Answer 1

This is probably an issue with the debugger and multiple threads, try putting the lock around the outside of the if statement rather than inside the property.