Automapper asp.net 核心控制器 - 映射器未初始化错误

Question

我一直在看这个文档https://automapper.readthedocs.io/en/stable/Getting-started.html 尝试配置 automapper 以消除一些手动属性映射的痛苦。

我遇到了以下错误：

消息：System.InvalidOperationException：映射器未初始化。使用适当的配置调用初始化。如果您尝试通过容器或其他方式使用映射器实例，请确保您没有对静态 Mapper.Map 方法的任何调用，并且如果您使用 ProjectTo 或 UseAsDataSource 扩展方法，请确保传入适当的 IConfigurationProvider实例。

这一点 - “映射器未初始化。使用适当的配置调用初始化” - 令人担忧，因为我觉得我已经在我的 startup.cs 文件中做到了。

我有以下控制器动作：

[HttpPost]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> Index(NewCreditCardApplicationDetails applicationDetails)
    {
        if (!ModelState.IsValid)
        {
            return View(applicationDetails);
        }

        CreditCardApplication creditCardApplication = Mapper.Map<CreditCardApplication>(applicationDetails);

        //var creditCardApplication = new CreditCardApplication
        //{
        //    FirstName = applicationDetails.FirstName,
        //    LastName = applicationDetails.LastName,
        //    Age = applicationDetails.Age.Value,
        //    GrossAnnualIncome = applicationDetails.GrossAnnualIncome.Value,
        //    FrequentFlyerNumber = applicationDetails.FrequentFlyerNumber
        //};

        await _applicationRepository.AddAsync(creditCardApplication);

        return View("ApplicationComplete", creditCardApplication);
    }

注释行表示确实有效但我想删除的代码。

我在我的 asp.net 核心网络应用程序的 startup.cs 文件中的配置方法如下所示：

public void Configure(IApplicationBuilder app, IHostingEnvironment env, AppDbContext dbContext)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();

            dbContext.Database.EnsureCreated();
        }
        else
        {
            app.UseExceptionHandler("/Home/Error");
            app.UseHsts();
        }

        app.UseHttpsRedirection();
        app.UseStaticFiles();
        app.UseCookiePolicy();

        Mapper.Initialize(cfg =>
        {
            cfg.CreateMap<NewCreditCardApplicationDetails, CreditCardApplication>();
        });

        app.UseMvc(routes =>
        {
            routes.MapRoute(
                name: "default",
                template: "{controller=Home}/{action=Index}/{id?}");
        });
    }

NewCreditCardApplicationDetails.cs 如下所示：

public class NewCreditCardApplicationDetails
{
    [Display(Name = "First Name")]
    [Required(ErrorMessage = "Please provide a first name")]
    public string FirstName { get; set; }

    [Display(Name = "Last Name")]
    [Required(ErrorMessage = "Please provide a last name")]
    public string LastName{ get; set; }

    [Display(Name = "Age (in years)")]
    [Required(ErrorMessage = "Please provide an age in years")]
    [Range(18,int.MaxValue, ErrorMessage = "You must be at least 18 years old")]
    public int? Age { get; set; }

    [Display(Name = "Gross Income")]
    [Required(ErrorMessage = "Please provide your gross income")]        
    public decimal? GrossAnnualIncome { get; set; }
    public string FrequentFlyerNumber { get; set; }
}

CreditCardApplication.cs 如下所示：

public class CreditCardApplication
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public int Age { get; set; }
    public decimal GrossAnnualIncome { get; set; }
    public string FrequentFlyerNumber { get; set; }
}

谁能看看是什么问题？

谢谢。

Answer 1

查看：https://medium.com/ps-its-huuti/how-to-get-started-with-automapper-and-asp-net-core-2-ecac60ef523f

你应该注入映射器来使用它，不要使用静态的。