具有相似主体的通用和非通用方法

Question

我有一个使用ExecuteAsyncServiceRequest重载调用的方法，您会注意到这两个方法的主体是相似的。我发现自己想知道是否有更简洁的方式来编写这些方法？具体来说，不必在方法主体中重复自己。

提前致谢！

    /// <summary>
    /// Executes an async service request which returns a response of type TResponse
    /// </summary>
    /// <param name="execute">The service request to execute</param>
    /// <param name="success">Callback when the service request is successful</param>
    /// <param name="failure">Callback when the service request fails</param>
    /// <typeparam name="TResponse">Type of the expected ServiceResult returned from the async request</typeparam>
    protected async void ExecuteAsyncServiceRequest<TResponse>(Func<Task<ServiceResult<TResponse>>> execute,
                                                            Action<TResponse> success,
                                                            Action<string> failure)
    {
        ServiceResult<TResponse> result = await execute();

        if (result.ResultCode == ServiceResult.ServiceResultCode.Failed)
            failure(result.FailureDetails);

        success(result.Response);    
    }

    /// <summary>
    /// Executes an async service request
    /// </summary>
    /// <param name="execute">The service request to execute</param>
    /// <param name="success">Callback when the service request is successful</param>
    /// <param name="failure">Callback when the service request fails</param>       
    protected async void ExecuteAsyncServiceRequest(Func<Task<ServiceResult>> execute,
                                                    Action success,
                                                    Action <string> failure)
    {
        ServiceResult result = await execute();

        if (result.ResultCode == ServiceResult.ServiceResultCode.Failed)
            failure(result.FailureDetails);

        success();
    }

Answer 1

不。不幸的是，这是由于 .NET 本身类型系统的限制 - 具体来说，它void不是一种类型。

具有更多功能影响的语言（与经典的 OOP 相对）往往没有void;的概念。相反，unit存在一种具有单个值的特殊类型（通常称为 ）。像这样的东西：

public sealed class Unit {
  private Unit() { }
  public static Unit Instance { get; } = new Unit();
}

您可以对代码执行类似的操作，但这取决于您是否值得：

protected async void ExecuteAsyncServiceRequest(Func<Task<ServiceResult>> execute,
                                                Action success,
                                                Action <string> failure) =>
    ExecuteAsyncServiceRequest(
        async () => new ServiceResult<Unit>(await execute(), Unit.Instance),
        _ => success(),
        failure);

这是假设ServiceResult<T>可以有一个（可能internal）构造函数作为ServiceResult参数并复制其所有属性，除了从第二个构造函数参数复制的实际“结果”之外。