def app_shutdown() -> None:
        state.app_shutdown = True

    router = APIRouter()

    @router.on_event("startup")
    def router_startup() -> None:
        state.router_startup = True

    @router.on_event("shutdown")
    def router_shutdown() -> None:
        state.router_shutdown = True

    sub_router = APIRouter()

    @sub_router.on_event("startup")
    def sub_router_startup() -> None:

from fastapi import FastAPI
from fastapi.testclient import TestClient

app = FastAPI()

items = {}


@app.on_event("startup")
async def startup_event():
    items["foo"] = {"name": "Fighters"}
    items["bar"] = {"name": "Tenders"}


@app.get("/items/{item_id}")
async def read_items(item_id: str):
    return items[item_id]


def test_read_items():
    with TestClient(app) as client:

from fastapi import FastAPI

app = FastAPI()


@app.on_event("shutdown")
def shutdown_event():
    with open("log.txt", mode="a") as log:
        log.write("Application shutdown")


@app.get("/items/")
async def read_items():

from fastapi import FastAPI

app = FastAPI()

items = {}


@app.on_event("startup")
async def startup_event():
    items["foo"] = {"name": "Fighters"}
    items["bar"] = {"name": "Tenders"}


@app.get("/items/{item_id}")
async def read_items(item_id: str):

        return decorator

    @deprecated(
        """
        on_event is deprecated, use lifespan event handlers instead.

        Read more about it in the
        [FastAPI docs for Lifespan Events](https://fastapi.tiangolo.com/advanced/events/).
        """
    )
    def on_event(
        self,
        event_type: Annotated[
            str,
            Doc(

MotorClient](https://stackoverflow.com/questions/41584243/runtimeerror-task-attached-to-a-different-loop)), то не забывайте создавать экземпляры объектов, которым нужен цикл событий (event loop), только внутри асинхронных функций, например, в `@app.on_event("startup")` callback.

///...

[MongoDB'nin MotorClient](https://stackoverflow.com/questions/41584243/runtimeerror-task-attached-to-a-different-loop) kullanımı), event loop gerektiren nesneleri yalnızca async fonksiyonların içinde oluşturmanız gerektiğini unutmayın; örneğin bir `@app.on_event("startup")` callback'i içinde.

///...

            self.on_shutdown.append(func)

    @deprecated(
        """
        on_event is deprecated, use lifespan event handlers instead.

        Read more about it in the
        [FastAPI docs for Lifespan Events](https://fastapi.tiangolo.com/advanced/events/).
        """
    )
    def on_event(
        self,
        event_type: Annotated[
            str,
            Doc(

[MongoDBs MotorClient](https://stackoverflow.com/questions/41584243/runtimeerror-task-attached-to-a-different-loop)), dann denken Sie daran, Objekte zu instanziieren, die einen Event Loop nur innerhalb asynchroner Funktionen benötigen, z. B. einen `@app.on_event("startup")`-Callback.

///...

your tests (e.g. when using [MongoDB's MotorClient](https://stackoverflow.com/questions/41584243/runtimeerror-task-attached-to-a-different-loop)), remember to instantiate objects that need an event loop only within async functions, e.g. an `@app.on_event("startup")` callback.

///...