.NET Core Web API - 如何從 ActionResult 獲取響應信息

Question

我有一個 WebAPI 核心端點方法，我使用內部庫 (RequestLogManager) 來保存來自和傳入請求的請求和響應數據。

因為我想記錄響應代碼和正文，所以我將 ActionResult 存儲在方法結束時返回的變量中（而不是從方法中的多個位置返回）。 例子：

    // This is a contrived method to illustrate the issue.
    
    [Route("test/actionresult/{testParam:int}")]
    [HttpGet]
    public async Task<ActionResult> GetTestActionResult(int testParam)
    {
        ActionResult actionResult = Ok(); // Default

        // Log Incoming Request
        int requestlogid = await RequestLogManager.LogIncomingRequestAsync("API - GetTestActionResult", Request);

        switch (testParam)
        {
            case 204:
                actionResult = NoContent();
                break;

            case 404:
                actionResult = NotFound();
                break;

            case 500:
                actionResult = StatusCode(StatusCodes.Status500InternalServerError, "An Error Occurred!");
                break;

            default:
                break;
        }

        // Log Outgoing Response
        RequestLogManager.LogResponseForRequestNoWait(requestlogid, ??? ResponseBody ???, ??? ResponseCode ???);

        return actionResult;
    }

在我的方法結束時，如何從 ActionResult 獲取響應代碼和正文的值以記錄？

• 我嘗試使用 Response.Body 和 Response.StatusCode，但它們總是“”和 200（我推測是因為我使用的是 ActionResult 而不是實際創建 HttpResponse）。
• 我嘗試將 ActionResult 轉換為 ObjectResult - ObjectResult 在屬性 StatusCode 和 Value 中確實有這些 - 但這會導致錯誤消息： Unable to cast object of type 'Microsoft.AspNetCore.Mvc.NoContentResult' to type 'Microsoft.AspNetCore.Mvc.ObjectResult'

Answer 1

中間件是 go 處理請求和響應日志的方式。 您可以自定義中間件，它們可以連接到HTTP管道，您可以在中間件實現中執行日志記錄。 這種方法可以幫助您在全球范圍內進行。

創建中間件以攔截請求和響應

// Request Logging middleware
public class RequestLoggingMiddleware
{
    private RequestDelegate _next;
    public RequestLoggingMiddleware(RequestDelegate next)
    {
        _next = next;
    }

    public async Task Invoke(HttpContext context)
    {
        // Logic to log your request. Can be accessed via "context.Request"
        await _next.Invoke(context);
    }
}

// Response Logging Middleware
public class ResponseLoggingMiddleware
{
    private RequestDelegate _next;
    public ResponseLoggingMiddleware(RequestDelegate next)
    {
        _next = next;
    }

    public async Task Invoke(HttpContext context)
    {
        // observe the Invoke() method being called first
        await _next.Invoke(context)
        // This is where your logging logic goes. For eg., you can capture 404 as below
        if(context.Response.StatusCode == 404)
        {
            // log the 404 and do whatever you want to do on a 404 here.
        }
    }
}

將中間件連接到HTTP管道

這非常簡單，可以通過以下代碼語句完成。

// Within the Configure() method of Startup.cs
app.UseMiddleware<ResponseLoggingMiddleware>();
app.UseMiddleware<RequestLoggingMiddleware>();

連接中間件的順序在這里很重要。 有關中間件排序和一般中間件的更多信息，請點擊此處

更新：

創建自定義屬性以處理端點級別的日志記錄

public class LoggingAttribute : Attribute, IActionFilter
{
    public void OnActionExecuted(ActionExecutedContext context)
    {
        // This method is called just right after the completion of the 
        // execution of the action method. Status Code can be obtained as shown below
        // response logging based on status code goes here.
        var result = context.Result;
        var response = context.HttpContext.Response.StatusCode;
    }

    public void OnActionExecuting(ActionExecutingContext context)
    {
        // This method is called before the action method is invoked.
        // Access the request using context.HttpContext.Request
        // and include the logging logic where
        var request = context.HttpContext.Request;            
    }
}

現在可以將此屬性添加到 controller 內的操作方法中，只要需要，如下所示。

[HttpGet]
[LoggingAttribute]
public ActionResult<IEnumerable<string>> Get()
{
    // ...other code
}