Question

目的是让控制器在我的自定义服务中使用异步方法。

控制器：

[Route("api/data/summary")]
[HttpGet]
public async Task<IHttpActionResult> Get()
{
    var result = await DataService.GetDataObjects();
    return Ok(result);
}

服务：

public static async Task<IEnumerable<DataObject>> GetDataObjects()
{
    var apiKey = "some-api-key";
    var path = "path-to-external-service";
    using (var client = new HttpClient())
    {
        var dataToProcess = // some data object

        client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", apiKey);
        client.BaseAddress = new Uri(path);

        HttpResponseMessage response = await client.PostAsJsonAsync("", dataToProcess);
        var content = await response.Content.ReadAsStringAsync();

        var result = MakeEntities(content); // some logic

        return result;
    }
}

但我遇到的问题是，在服务实际处理完数据之前，控制器的操作会返回空结果。

您能否建议如何正确实施？

Answer 1

您的代码没问题，控制器似乎在GetDataObjects返回值之前没有返回值。

以下情况除外：

MakeEntities使用了一些异步操作，你不在MakeEntities中等待它。所以MakeEntities返回任务。
代码运行时异常会增加。确保GetDataObjects和MakeEntities代码正常运行。

Answer 2

目的是让控制器在我的自定义服务中使用异步方法。

控制器：

[HttpGet]
[Route("api/data/summary")]
public async Task<IHttpActionResult> Get()
{
    var result = await DataService.GetDataObjects().ConfigureAwait(false);
    return Ok(result);
}

服务：

public static async Task<ResponseEntity> GetDataObjects()
{
    ResponseEntity response = new ResponseEntity();
    var apiKey = "some-api-key";
    var path = "path-to-external-service";
    using (var client = new HttpClient())
    {
        var dataToProcess = // some data object    
        client.BaseAddress = new Uri(path);
        client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", apiKey);
        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));    
        HttpResponseMessage response = await client.PostAsJsonAsync("", dataToProcess).ConfigureAwait(false);
        string responseString = await response.Content.ReadAsStringAsync().ConfigureAwait(false);    
        var result = JsonConvert.DeserializeObject<ResponseEntity>(responseString);

        return response;
    }
}

WebAPI：在业务逻辑中使用异步方法

2 个答案: