Can I glue this crack as a temporary solution? I suddenly noticed a crack in my frame. 

Is it practical for me to use glue to seal it off as a temporary solution? 



Edit: Further information  ...two incidents so far. Someone opened their driver side door on me and I slammed into it. That considerably weakened it. Then I fell again while turning a sharp corner, it broke it.

Update from 29th Jan 2019:


I went to a bike shop and they told me they could not replace it; I need to talk to the shop where I bought it from and get a replacement from them. Does it have to go this way? I would imagine this fork could be easily replaced.
No.

The consequences of fork failure are likely to be severe and painful. This may only be a secondary fork crown but it's still structural. The fact that it's such a wide crack means something is already deformed and weakened. Any glue joint would be under huge stress and aluminium doesn't glue well. If this happened out on the trail it might be possible to ride back to civilisation at walking pace on a fire road, but I'd probably rather scoot the bike standing on one pedal. As your picture indicates it's indoors, you need a new fork before riding it anywhere. 

I wouldn't even ride it to a bike shop.

More generally (thanks to cmaster): Never ride a bike where there's so much as a crack in a) the front axle, b) any part of the fork, including the steering tube, c) the stem, or d) the handlebar. There is zero backup for any of these parts, and failure usually means immediate loss of control and consequently unmitigated crash.