Aditya Manthramurthy <******@****.***> 1760547645 -0700

Klaus Post <******@****.***> 1739895955 -0800

Klaus Post <******@****.***> 1759093161 +0200

Mark Theunissen <******@****.***> 1719991040 +1000

有些情況需要在 HTTP 錯誤回應中加入自訂標頭，例如某些安全性情境。

你大概不需要在程式碼中直接使用。

但若你在進階情境中需要，可以這樣加入自訂標頭：

{* ../../docs_src/handling_errors/tutorial002_py310.py hl[14] *}

## 安裝自訂例外處理器 { #install-custom-exception-handlers }

你可以使用 [Starlette 的相同例外工具](https://www.starlette.dev/exceptions/) 來加入自訂例外處理器。

假設你有一個自訂例外 `UnicornException`，你（或你使用的函式庫）可能會 `raise` 它。

而你想用 FastAPI 全域處理這個例外。

你可以使用 `@app.exception_handler()` 加入自訂例外處理器：

participant client as Client
participant handler as Exception handler
participant dep as Dep with yield
participant operation as Path Operation
participant tasks as Background tasks

    Note over client,operation: Can raise exceptions, including HTTPException
    client ->> dep: Start request
    Note over dep: Run code up to yield
    opt raise Exception
        dep -->> handler: Raise Exception

participant client as Client
participant handler as Exception handler
participant dep as Dep with yield
participant operation as Path Operation
participant tasks as Background tasks

    Note over client,operation: Can raise exceptions, including HTTPException
    client ->> dep: Start request
    Note over dep: Run code up to yield
    opt raise Exception
        dep -->> handler: Raise Exception

    client ->> dep: Startet den Request
    Note over dep: Führt den Code bis zum yield aus
    opt Löst Exception aus
        dep -->> handler: Löst Exception aus
        handler -->> client: HTTP-Error-Response
    end
    dep ->> operation: Führt Abhängigkeit aus, z. B. DB-Session
    opt Löst aus
        operation -->> dep: Löst Exception aus (z. B. HTTPException)
        opt Handhabt

jiuker <******@****.***> 1754621164 +0800

participant client as Client
participant handler as Exception handler
participant dep as Dep with yield
participant operation as Path Operation
participant tasks as Background tasks

    Note over client,operation: Can raise exceptions, including HTTPException
    client ->> dep: Start request
    Note over dep: Run code up to yield
    opt raise Exception
        dep -->> handler: Raise Exception