c# - 如何在控制台应用程序 C# 中使用异步等待

Question

这是存储库中的方法:

public async Task<IEnumerable<T>> FindAll()
    {
        IQueryable<T> query = this.Context.Set<T>();
        return await query.Select(e => e).ToListAsync();
    }


public class Program
{
    static void Main(string[] args)
    {
        DB dB = new DB();
        IUnitOfWork unitOfWork = new UnitOfWork(dB);
        Task<IEnumerable<User>> users = unitOfWork.UserRepository.FindAll();
        users.Wait();
        Console.WriteLine(users);
    }
}

当我运行我的代码时，我得到:

System.Runtime.CompilerServices.AsyncTaskMethodBuilder'1+AsyncStateMachineBox'1[System.Collections.Generic.IEnumerable'1[PasteBook.WebApi.Models.User],PasteBook.WebApi.Repositories.GenericRepository'1+d__5[PasteBook.WebApi.Models.User]]

Answer 1

最简单的选择就是使用异步入口点:

public class Program
{
    // async Main method, with a Task return type
    static async Task Main(string[] args)
    {
        DB dB = new DB();
        IUnitOfWork unitOfWork = new UnitOfWork(dB);
        // It's fine to await within the async method
        var users = await unitOfWork.UserRepository.FindAll();
        foreach (var user in users)
        {
            Console.WriteLine(user);
        }
    }
}

(请注意，此答案并不试图解决您是否应该使用这种特定的数据库访问模式 - 它的重点是“如何从控制台应用程序使用 await”。)