I do one-armed hangs fairly frequently, but then I weigh only 140lbs/64kg. These kind of moves definitely favour the shorter, lighter athlete.
Obviously, jumping up and grabbing the bar with just one hand is a very bad way to approach this move: Take hold of the bar with two hands, pack your shoulders tight and very carefully and gradually relax your grip with one hand. You should be able to tell without letting go of the bar whether or not your shoulder is up to the task of supporting your weight.
Make sure you're in a position where you can let go of the bar completely without risking injury, i.e. not too far from the ground, and once you're comfortable 'half-gripping' the bar with one hand, release your grip with that hand entirely. If you feel your body start to twist or rotate and you're unable to control the movement, let go!
By all means give it a try but have realistic expectations and don't push yourself too hard. A move like this could take years to get down and, while it is an impressive feat, it's not worth injuring yourself over so train sensibly and stop when either your grip or your shoulders start to fatigue.