c# - 如何将异步任务存储在字典中并根据配置值调用它们？

Question

这是我的代码如下:

public interface IResponseEntity
{
}

public class ResponseEntity : IResponseEntity
{
    public string Status { get; set; }
    public string Message { get; set; }
    public string Data { get; set; }
}

public class ObjectForRequest
{
    public string abcd { get; set; }
    public string xyz { get; set; }
    public string pqrs { get; set; }
    public short mnop { get; set; }
}

private async Task<IResponseEntity> Dowork_for_A(ObjectForRequest objReq)
{
    //Code for A
    ....................
}

private async Task<IResponseEntity> Dowork_for_B(ObjectForRequest objReq)
{
    //Code for B
    ....................
}

private async Task<IResponseEntity> Dowork_for_C(ObjectForRequest objReq)
{
    //Code for C
    ....................
}

private async Task<IResponseEntity> Dowork_for_D(ObjectForRequest objReq)
{
    //Code for D
    ....................
}

public async Task<IResponseEntity> method(ObjectForRequest objReq)
{
    if (CONFIGVALUE == 'A')
        return await Dowork_for_A(RequestOBJ);
    else if (CONFIGVALUE == 'B')
        return await Dowork_for_B(RequestOBJ);
    else if (CONFIGVALUE == 'C')
        return await Dowork_for_C(RequestOBJ);
    else if (CONFIGVALUE == 'D')
        return await Dowork_for_D(RequestOBJ);
    else
        return null;
}

好像现在我正在检查 if 条件中的配置值，然后调用异步任务来返回值。
如何设置 <key, value>一对字典作为配置值作为“键”和“值”作为异步任务？或者换句话说，这里如何将异步任务存储在字典中并根据配置值调用它们？

Answer 1

这是非常简单的。像这样声明你的字典:

    Dictionary<char, Func<ObjectForRequest, Task<IResponseEntity>>> _actions =
         new Dictionary<char, Func<ObjectForRequest, Task<IResponseEntity>>>()
    {
        { 'A', Dowork_for_A },
        { 'B', Dowork_for_B }
        // ...
    }

然后:

public async Task<IResponseEntity> method(ObjectForRequest objReq)
{
     Func<ObjectForRequest, Task<IResponseEntity>> action;
     if (!_actions.TryGetValue(CONFIGVALUE, out action))
     {
          return null;
     }   
     return await action(objReq);
}

另外，请务必考虑这对性能的影响。字典对于大集合来说非常快，但如果你真的只有 3 或 4 个选项， switch或 if ... else链几乎肯定会更快。确切的临界点是什么时候 Dictionary变得更好很难说。