如何返回带有详细错误消息的错误？

Question

I use the following code in an ASP.NET Core project to return a detailed error message (business logic related errors):

public async Task<IEnumerable<PoolStatic>> Get(string id)
{
    if (id== null)
    {
        var resp = new HttpResponseMessage(HttpStatusCode.BadRequest)
        {
            Content = new StringContent("id is not provided."),
            ReasonPhrase = "id not found"
        };
        throw new HttpResponseException(resp);
    }
 ....

However, the client gets HTTP 500 and the raw response message doesn't contain the message I set:

HTTP/1.1 500 Internal Server Error
Date: Sat, 10 Dec 2016 02:19:09 GMT
Content-Length: 0
Server: Kestrel

Answer 1

In ASP.NET Core, a better way to achieve this behavior would be to return a Task<IActionResult> from the controller, which lets you do this:

public async Task<IActionResult> Get(string id)
{
    if (id== null)
    {
        return BadRequest("id is not provided.");
    }

    // other code, including:
    // return Ok(some data);
}

BadRequest() is a helper method that creates a BadRequestObjectResult , and sends a 400 Bad Request response back to the client with whatever data you provide.