private long i;

@SubscribeEvent
	public void onstop(FMLServerStoppedEvent e) {
		i=0;
	}

	@SubscribeEvent
	public void onDeath(RenderWorldLastEvent e) {
		i++;
		if(i==1) {		
			Minecraft mc = Minecraft.getInstance();
			mc.getIntegratedServer().shareToLAN(GameType.ADVENTURE, false, 25565);
			ITextComponent itextcomponent = new TranslationTextComponent("本地游戏已在端口"+Minecraft.getInstance().getIntegratedServer().getServerPort()+"上开启 ");
			mc.ingameGUI.getChatGUI().printChatMessage(itextcomponent);	
		}
	}

This is the way I currently think of ，   Since RenderWorldLastEvent is rendering the world all the time, I can only do this. Can you provide other events that are executed only once after entering the map?

@SubscribeEvent
	public void onjon(PlayerLoggedInEvent e) {	
			Minecraft mc = Minecraft.getInstance();
			mc.getIntegratedServer().shareToLAN(GameType.SURVIVAL, true, 25565);
			ITextComponent itextcomponent = new TranslationTextComponent("本地游戏已在端口"+Minecraft.getInstance().getIntegratedServer().getServerPort()+"上开启 ");
			mc.ingameGUI.getChatGUI().printChatMessage(itextcomponent);	
	}

Enter the map :

   The game crashes :

   AL lib: (EE) alc_cleanup: 1 device not closed

 

This event doesn't work. Same as FMLServerStartingEvent! !

FMLServerStartingEvent & FMLServerStoppedEvent & FMLPlayerLoggedInEvent = Server Only

RenderWorldLastEvent & Minecraft.getInstance() = Client Only

 

Mixing "Server Only" and "Client Only" = Very Bad, Not Working

 

You could take a look at EntityJoinTheWorldEvent and use a flag. I personally dont know the best Client Side event for this