Error on the mouse input about directxtk HOT 1 CLOSED

The output of the Error Window can be confusing, so I recommend looking at the actual compiler output in the Build window instead for details.

That said, this does not look like valid C++ code:

    if (rect(state.positionMode()))
        return true;

rect is a RECT struct and doesn't have an operator().

The error is probably because this syntax state.positionMode() is trying to treat the simple value of state.positionMode as a function pointer. It isn't a method, so you'd just use state.positionMode.

As with previous questions, you'd be well served to spend some time reading over a basic C/C++ programming tutorial.

from directxtk.