Automapper不会忽略嵌套属性

Question

我已经浏览了各种类似的帖子，但无法发现我用这个方法的错误。基本上我有两个视图更新“设置”对象的不同部分。视图模型包含两个属性中的一个，并且根据要设置的属性，应忽略另一个。它的ViewModel ==＆gt;它工作正常。实体直接但当Automapper尝试更新嵌套对象时失败。

我有以下对象结构：

public class Account
{
    public int AccountId { get; set; }
    public DateTime DateToBeIgnored { get; set; }
    public AccountSetting Settings { get; set; }
}

public class AccountSetting
{
    public string PropertyOne { get; set; }
    public string PropertyTwo { get; set; }
}

public class AccountViewModel
{
    public int AccountId { get; set; }
    public DateTime DateToBeIgnored { get; set; }
    public AccountSettingViewModel Settings { get; set; }
}

public class AccountSettingViewModel
{
    public string PropertyTwo { get; set; }
}

public class OtherAccountSettingViewModel
{
    public string PropertyOne { get; set; }
}

使用映射：

void WireUpMappings()
{
    // From the entities to the view models
    Mapper.CreateMap<Account, AccountViewModel>();
    Mapper.CreateMap<AccountSetting, AccountSettingViewModel>();
    Mapper.CreateMap<AccountSetting, OtherAccountSettingViewModel>();

    // From the view models to the entities
    Mapper.CreateMap<AccountViewModel, Account>()
        .ForMember(dest => dest.DateToBeIgnored, opt => opt.Ignore());

    Mapper.CreateMap<AccountSettingViewModel, AccountSetting>()
        .ForMember(dest => dest.PropertyTwo, opt => opt.Ignore());

    Mapper.CreateMap<OtherAccountSettingViewModel, AccountSetting>()
        .ForMember(dest => dest.PropertyOne, opt => opt.Ignore());

    Mapper.AssertConfigurationIsValid();
}

映射[OtherAccountSettingViewModel - ＆gt; AccountSetting]，只分配属性“PropertyTwo”（“PropertyOne”的原始值保持不变） - 这就是我所期望的。

但是在映射[AccountViewModel - ＆gt;帐户]“DateToBeIgnored”按预期被忽略，而Account.AccountSetting.PropertyTwo的先前值被替换为“null”。

有人能发现我的错误吗？

Answer 1

以下是解决方案：

[TestMethod]
public void TestMethod1()
{
     Mapper.CreateMap<AccountViewModel, Account>()
        .ForMember(dest => dest.DateToBeIgnored, opt => opt.Ignore())
        .ForMember(dest=>dest.Settings, opt=>opt.UseDestinationValue());

    Mapper.CreateMap<AccountSettingViewModel, AccountSetting>()
        .ForMember(dest=>dest.PropertyOne, opt=>opt.Ignore())
        .ForMember(dest => dest.PropertyTwo, opt => opt.MapFrom(a => a.PropertyTwo));

    Mapper.AssertConfigurationIsValid();

    AccountViewModel viewmodel = new AccountViewModel()
    {
        AccountId = 3,
        DateToBeIgnored = DateTime.Now,
        Settings = new AccountSettingViewModel() { PropertyTwo = "AccountSettingViewModelPropTwo" }
    };

    Account account = new Account()
    {
        AccountId = 10,
        DateToBeIgnored = DateTime.Now,
        Settings = new AccountSetting() { PropertyOne = "AccountPropOne", PropertyTwo = "AccountPropTwo" }
    };

    account = Mapper.Map<AccountViewModel, Account>(viewmodel, account);

    Assert.IsNotNull(account);

}