How do I upgrade an item in hand?

[Amperka_pro]

In general, I decided to work on NBT tags. Using the NbttagCompound class but ran into an incomprehensible problem. If I get the ItemStack via Minecraft.getMinecraft (). Player.getHeldItemMainHand () and use the item.setTagCompound (/ * something * /) method and then immediately throw the item, then the changes will not be applied, and if via PlayerInteractEvent.RightClickItem event
and get ItemStack item = event.getItemStack () then after operations with nbt and item drop, it will be applied. Why is that? I noticed that in the first case, if you install nbt and immediately open the inventory, then nbt will be applied, since the item will move up and then down. In the second case, the object will immediately move back and forth. How to do this with a method?

 

Forge 1.12 - 1.16

 

If anyone knows at 1.12 then tell me, at 1.16 it will do too

[Amperka_pro]

3 минуты назад diesieben07 сказал:

Это не так.

Укажите версию, которую вы используете, ответ может сильно отличаться.

If I write 1.12, then you will close the question, and if 1.16 then it may not match. How to be?

Edited January 20, 2021 by Amperka_pro

[Amperka_pro]

I tried to transfer from the same slot to this one, but it did not work. Tried doing Right click

[Amperka_pro]

2 minutes ago, diesieben07 said:

Обновитесь до 1.16, тогда мы вам поможем. Оставайтесь на версии 1.12, и вам не помогут. Просто как тот.

 

Это ваше последнее предупреждение.

Well, buy a normal computer, then I'll upgrade. Of course it's easy to say, they themselves would have been in my shoes.

[Amperka_pro]

The main thing is the new version is released, but the optimization is forgotten. People say that even on normal computers it freezes, what should I do with 2 gigabytes of RAM ((((