c# - 如何在 ASP.NET Web API 异步 Controller 方法中返回对象列表

Question

如何在 ASP.NET Web API 异步 Controller 方法中返回对象列表或将列表包装在 Task 对象中？

类:

public class SubscriberHistory
{
  public string Date;
  public string Message;

  public SubscriberHistory(string Date, string Message)
  {
    this.Date = Date;
    this.Message = Message;
  }
}

Controller :

[HttpGet("[action]/{accountNumber}")]
public Task<SubscriberHistory> GetSubscriberHistory(string accountNumber)
{
    SubscriberManager subsManager = new SubscriberManager();
    return subsManager.GetSubscriberHistoryByAccountNumber(accountNumber);
}

Controller 管理器:

public async List<SubscriberHistory> GetSubscriberHistory()
{
    List<SubscriberHistory> List = new List<SubscriberHistory>();
    // HttpClient get data
    return List; // ?
}

Answer 1

永远不要返回 Task如果您没有执行任何操作，则来自操作方法async : 它没有用，还会给您的通话增加不必要的开销。

要返回对象列表，只需声明正确的返回类型:

[HttpGet("[action]/{accountNumber}")]
public List<SubscriberHistory> GetSubscriberHistory(string accountNumber)
{
    SubscriberManager subsManager = new SubscriberManager();
    return subsManager.GetSubscriberHistoryByAccountNumber(accountNumber);
}

相反，如果您想异步执行此操作，则必须返回 Task<T>并等待结果:

[HttpGet("[action]/{accountNumber}")]
public async Task<List<SubscriberHistory>> GetSubscriberHistory(string accountNumber)
{
    SubscriberManager subsManager = new SubscriberManager();
    return await subsManager.GetSubscriberHistoryByAccountNumber(accountNumber);
}

在你的经理中:

public async Task<List<SubscriberHistory>> GetSubscriberHistory()
{
    List<SubscriberHistory> list = new List<SubscriberHistory>();
    var result = await client.GetAsync("http://myhost/mypath");
    //Your code here
    return list;
}