Question

我想知道如何使用新值更新现有对象。我有一个简单的帐户对象，具有以下属性

public class Account
{
    public int Id {get; set;}
    public string Forename {get; set;}
    public string Surname {get; set;}
    public DateTime RegisterDate {get; set;}
    public string Occupation {get; set;}
}

在我的项目中，我有一个简单的编辑方法，允许用户更新他们的Forename，Surname和Occupation。

public ActionResult Edit()
{
     return View();
}

[HttpPost]
public ActionResult Edit(Account editFormDetails)
{
    var accountDetails = GetAccountDetails(account.Id) //Gets a users existing details from db

    return RedirectToAction("Index");
}

是否有一种使用editFromDetails对象中的新值更新现有对象（accountDetails）的好方法？我会做克隆，但是，我的编辑表单中的字段可以留空，所以我可能不需要更新。我在这个例子中简化了我的对象，使其不那么冗长。任何帮助都会很棒。

Answer 1

使用NuGet安装名为AutoMapper

的库

PM＆GT;安装包AutoMapper

安装完成后，您需要在要更新的每个类型之间创建地图，如果类型的属性匹配（如下面给出的示例中所示），则库将自动能够将这些属性相互映射......

void Main()
{
    AutoMapper.Mapper.CreateMap<ChangeNameViewModel, User>()
        .ForMember(member => member.FirstName, viewModel => viewModel.Condition(source => !string.IsNullOrWhiteSpace(source.FirstName)))
        .ForMember(member => member.LastName, viewModel => viewModel.Condition(source => !string.IsNullOrWhiteSpace(source.LastName)));


    User user = new User 
    { 
        FirstName = "Jane", 
        LastName = "Doe", 
        UserId = Guid.NewGuid().ToString() 
    };

    ChangeNameViewModel model = new ChangeNameViewModel 
    { 
        FirstName = "John" 
    };

    user = AutoMapper.Mapper.Map<ChangeNameViewModel, User>(model, user);

    Console.WriteLine ("First name:  {0}", user.FirstName);
    Console.WriteLine ("Last name:   {0}", user.LastName);
    Console.WriteLine ("UserId: {0}", user.UserId);

    // Output should be:
    // ---------------------------
    // First name:  John
    // Last name:   Doe
    // UserId:      9fd25bfd-c978-4287-8d3d-890d67834c23
    // ---------------------------
}

public class User 
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string UserId { get; set; }
}

public class ChangeNameViewModel 
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

使用新值更新现有对象

1 个答案: