Boost converter Inductor Current
It depends on the output voltage.

At the start, when the capacitor is discharged, there will still be a positive voltage across the inductor and the current will continue to build in the inductor during the switch open cycle.

When the output capacitor voltage reaches the same level as the supply voltage the voltage across the inductor will be zero during the off cycle. After that the voltage on the capacitor will be greater than the supply voltage. From then on the inductor loses it's charge during the off cycle.