The electric field within a charged cylinder shell is NOT zero when you have a coaxial conductor inside that is held at a different potential than the outer shell. This is already the case in a cylindrical capacitor with coaxial metal electrodes. If in such a coaxial cylindrical capacitor (with an insulator filling the space between the electrodes), you replace the inner metal with a semiconductor and attach ohmic contacts to both ends of the semiconducting cylinder then you already have, in principle, a wrap-around gate metal-insulator-semiconductor field-effect-transistor (MISFET). In this an applied voltage between the outer metal (gate) and the inner semiconductor creates an electric field inducing a charge on the inner semiconductor producing a conducting inversion channel that can be controlled by the applied gate voltage between the outer metal and the inner semiconductor (usually one contact called source). This can be used to modulate the current produced by an applied voltage (drain-source voltage) between the contacts at the ends of the inner semiconductor which is then a wrap-around gate MISFET or MOSFET when the insulator is an oxide.
