具有实体框架的自动映射器，初始化错误

问题描述

我有一个使用Code First生成模型的EF6 MVC应用.我正在尝试使用AutoMapper在模型和该模型的视图模型表示之间创建映射.但是，当我执行映射时，会收到错误消息:

I have an EF6 MVC app using Code First to generate the models. I am trying to create a mapping using AutoMapper between the model and a view model representation of that model. However, when I do the mapping I receive the error:

我肯定是在初始化Mapper，但是我无法弄清为什么配置失败.在这种情况下，谁能提供一些帮助我成功使用AutoMapper的帮助?

I am definitely initializing the Mapper, but I am not able to figure out why the configuration is failing. Could anyone provide some assistance on what I can do to successfully use AutoMapper in this situation?

以下是我如何配置和初始化Mapper的代码:

Here is the code for how I am configuring and initializing the Mapper:

    var pTConnections = _db.PTConnections.Include(p => p.PTConnectionClass).ToList();

        Mapper.Initialize(cfg =>
        {
            cfg.CreateMap<PTConnection, PTConnectionViewModel>()
                .AfterMap((s, d) => { foreach (var i in d.PTCredentialAssignments) i.PTConnection = d; });

            cfg.CreateMap<PTCredentialAssignment, PTCredentialAssignmentViewModel>()
                .ForMember(m => m.PTCredential, opt => opt.Ignore())
                .ForMember(m => m.PTConnection, opt => opt.Ignore());

            cfg.CreateMap<PTVendor, PTVendorViewModel>()
                .ForMember(m => m.PTCredentials, opt => opt.Ignore())
                .ForMember(m => m.PTConnections, opt => opt.Ignore());

            cfg.CreateMap<PTCredential, PTCredentialViewModel>();

            cfg.CreateMap<PTConnectionClass, PTConnectionClassViewModel>()
                .ForMember(m => m.PTConnections, opt => opt.Ignore());

            cfg.CreateMap<PTConnectionContactAssignment, PTConnectionContactAssignmentViewModel>()
                .ForMember(m => m.PTConnection, opt => opt.Ignore());

        });

    var dest = Mapper.Map<List<PTConnection>, List<PTConnectionViewModel>>(pTConnections);

这是我的代码优先模型:

Here is my Code First Model:

public partial class PTConnection
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public PTConnection()
    {
        PTConnectionAssignments = new HashSet<PTConnectionAssignment>();
        PTCredentialAssignments = new HashSet<PTCredentialAssignment>();
        PTConnectionContactAssignments = new HashSet<PTConnectionContactAssignment>();
    }

    [Key]
    public int PTCID { get; set; }

    [Column(TypeName = "datetime2")]
    public DateTime ModifiedDate { get; set; }

    [Required]
    [StringLength(500)]
    public string ModifiedBy { get; set; }

    [Required]
    [StringLength(255)]
    public string ConnectionName { get; set; }

    [Required]
    [StringLength(100)]
    public string Host { get; set; }

    public int Port { get; set; }

    public string Comment { get; set; }

    public int PTCCID { get; set; }

    public bool? IsDisabled { get; set; }

    public int PTVID { get; set; }

    public virtual PTConnectionClass PTConnectionClass { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<PTConnectionAssignment> PTConnectionAssignments { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<PTCredentialAssignment> PTCredentialAssignments { get; set; }

    public virtual PTVendor PTVendor { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<PTConnectionContactAssignment> PTConnectionContactAssignments { get; set; }
}

public partial class PTCredential
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public PTCredential()
    {
        PTCredentialAssignments = new HashSet<PTCredentialAssignment>();
        PTCredentialContactAssignments = new HashSet<PTCredentialContactAssignment>();
    }

    [Key]
    public int PTCRID { get; set; }

    [Column(TypeName = "datetime2")]
    public DateTime ModifiedDate { get; set; }

    [Required]
    [StringLength(500)]
    public string ModifiedBy { get; set; }

    [Required]
    [StringLength(100)]
    public string CredUsername { get; set; }

    [Required]
    [StringLength(500)]
    public string CredPassword { get; set; }

    public string Directory { get; set; }

    public bool? IsDisabled { get; set; }

    public string Comments { get; set; }

    public int? PTVID { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<PTCredentialAssignment> PTCredentialAssignments { get; set; }

    public virtual PTVendor PTVendor { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<PTCredentialContactAssignment> PTCredentialContactAssignments { get; set; }
}

public partial class PTVendor
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public PTVendor()
    {
        PTConnections = new HashSet<PTConnection>();
        PTCredentials = new HashSet<PTCredential>();
        PTIneligableCredentialVendorAssignments = new HashSet<PTIneligableCredentialVendorAssignment>();
        PTVendorAssignments = new HashSet<PTVendorAssignment>();
        PTVendorContactAssignments = new HashSet<PTVendorContactAssignment>();
    }

    [Key]
    public int PTVID { get; set; }

    [Column(TypeName = "datetime2")]
    public DateTime ModifiedDate { get; set; }

    [Required]
    [StringLength(500)]
    public string ModifiedBy { get; set; }

    [Required]
    [StringLength(50), Display(Name="Vendor Name")]
    public string Name { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<PTConnection> PTConnections { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<PTCredential> PTCredentials { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<PTIneligableCredentialVendorAssignment> PTIneligableCredentialVendorAssignments { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<PTVendorAssignment> PTVendorAssignments { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<PTVendorContactAssignment> PTVendorContactAssignments { get; set; }
}

[Table("PTCredentialAssignment")]
public partial class PTCredentialAssignment
{
    [Key]
    public int PTCRAID { get; set; }

    [Column(TypeName = "datetime2")]
    public DateTime ModifiedDate { get; set; }

    [Required]
    [StringLength(500)]
    public string ModifiedBy { get; set; }

    public int PTCID { get; set; }

    public int PTCRID { get; set; }

    public virtual PTConnection PTConnection { get; set; }

    public virtual PTCredential PTCredential { get; set; }
}

[Table("PTConnectionClass")]
public partial class PTConnectionClass
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public PTConnectionClass()
    {
        PTConnections = new HashSet<PTConnection>();
    }

    [Key]
    public int PTCCID { get; set; }

    [Column(TypeName = "datetime2")]
    public DateTime ModifiedDate { get; set; }

    [Required]
    [StringLength(500)]
    public string ModifiedBy { get; set; }

    [Required]
    [StringLength(50)]
    public string Class { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<PTConnection> PTConnections { get; set; }
}

[Table("PTConnectionContactAssignment")]
public partial class PTConnectionContactAssignment
{
    [Key]
    public int PTCCAID { get; set; }

    [Column(TypeName = "datetime2")]
    public DateTime ModifiedDate { get; set; }

    [Required]
    [StringLength(500)]
    public string ModifiedBy { get; set; }

    public int PTCID { get; set; }

    [Required]
    [StringLength(60)]
    public string FirstName { get; set; }

    [Required]
    [StringLength(60)]
    public string LastName { get; set; }

    [Required]
    [StringLength(10)]
    public string PhoneNumber { get; set; }

    [StringLength(20)]
    public string Extension { get; set; }

    [StringLength(100)]
    public string Email { get; set; }

    [StringLength(60)]
    public string Title { get; set; }

    public string Comment { get; set; }

    public virtual PTConnection PTConnection { get; set; }
}

这是我的ViewModel:

Here is my ViewModel:

   public partial class PTConnectionViewModel
    {
        [Key]
        public int PTCID { get; set; }

        [Column(TypeName = "datetime2")]
        public DateTime ModifiedDate { get; set; }

        [Required]
        [StringLength(500)]
        public string ModifiedBy { get; set; }

        [Required]
        [StringLength(255)]
        public string ConnectionName { get; set; }

        [Required]
        [StringLength(100)]
        public string Host { get; set; }

        public int Port { get; set; }

        public string Comment { get; set; }

        public int PTCCID { get; set; }

        public bool? IsDisabled { get; set; }

        public int PTVID { get; set; }

        public virtual PTConnectionClassViewModel PTConnectionClass { get; set; }

        public virtual ICollection<PTConnectionAssignmentViewModel> PTConnectionAssignments { get; set; }

        public virtual ICollection<PTCredentialAssignmentViewModel> PTCredentialAssignments { get; set; }

        public virtual PTVendorViewModel PTVendor { get; set; }

        public virtual ICollection<PTConnectionContactAssignmentViewModel> PTConnectionContactAssignments { get; set; }
    }

public partial class PTVendorViewModel
{
    [Key]
    public int PTVID { get; set; }

    [Column(TypeName = "datetime2")]
    public DateTime ModifiedDate { get; set; }

    [Required]
    [StringLength(500)]
    public string ModifiedBy { get; set; }

    [Required]
    [StringLength(50), Display(Name="Vendor Name")]
    public string Name { get; set; }

    public virtual ICollection<PTConnectionViewModel> PTConnections { get; set; }

    public virtual ICollection<PTCredentialViewModel> PTCredentials { get; set; }

}

public partial class PTCredentialViewModel
{
    [Key]
    public int PTCRID { get; set; }

    [Column(TypeName = "datetime2")]
    public DateTime ModifiedDate { get; set; }

    [Required]
    [StringLength(500)]
    public string ModifiedBy { get; set; }

    [Required]
    [StringLength(100)]
    public string CredUsername { get; set; }

    [Required]
    [StringLength(500)]
    public string CredPassword { get; set; }

    public string Directory { get; set; }

    public bool? IsDisabled { get; set; }

    public string Comments { get; set; }

    public int? PTVID { get; set; }

    public virtual ICollection<PTCredentialAssignmentViewModel> PTCredentialAssignments { get; set; }

    public virtual PTVendorViewModel PTVendor { get; set; }

    public virtual ICollection<PTCredentialContactAssignmentViewModel> PTCredentialContactAssignments { get; set; }
}

public partial class PTCredentialAssignmentViewModel
{
    [Key]
    public int PTCRAID { get; set; }

    [Column(TypeName = "datetime2")]
    public DateTime ModifiedDate { get; set; }

    [Required]
    [StringLength(500)]
    public string ModifiedBy { get; set; }

    public int PTCID { get; set; }

    public int PTCRID { get; set; }

    public virtual PTConnectionViewModel PTConnection { get; set; }

    public virtual PTCredentialViewModel PTCredential { get; set; }
}

public partial class PTConnectionClassViewModel
{

    [Key]
    public int PTCCID { get; set; }

    [Column(TypeName = "datetime2")]
    public DateTime ModifiedDate { get; set; }

    [Required]
    [StringLength(500)]
    public string ModifiedBy { get; set; }

    [Required]
    [StringLength(50)]
    public string Class { get; set; }

    public virtual ICollection<PTConnectionViewModel> PTConnections { get; set; }
}

public partial class PTConnectionContactAssignmentViewModel
{
    [Key]
    public int PTCCAID { get; set; }

    [Column(TypeName = "datetime2")]
    public DateTime ModifiedDate { get; set; }

    [Required]
    [StringLength(500)]
    public string ModifiedBy { get; set; }

    public int PTCID { get; set; }

    [Required]
    [StringLength(60)]
    public string FirstName { get; set; }

    [Required]
    [StringLength(60)]
    public string LastName { get; set; }

    [Required]
    [StringLength(10)]
    public string PhoneNumber { get; set; }

    [StringLength(20)]
    public string Extension { get; set; }

    [StringLength(100)]
    public string Email { get; set; }

    [StringLength(60)]
    public string Title { get; set; }

    public string Comment { get; set; }

    public virtual PTConnectionViewModel PTConnection { get; set; }
}

推荐答案

只需将地图从一种类型创建为另一种即可.不要将地图从一种类型的列表创建为另一种类型的列表. Automapper可以自动处理集合.

Just create the map from one type to another. Don't create the map from a List of one type to a list of another type. Automapper can automatically handle collections.

实际上，您是在告诉Automapper如何将List<A>映射到List<B>，而没有告诉Automapper如何将A实际映射到B.将您的注册更改为以下内容:

In effect, you're telling Automapper how to map a List<A> to a List<B> without telling Automapper how to actually map A to B. Change your registration to the following:

Mapper.Initialize(cfg =>
{
    cfg.CreateMap<PTConnection, PTConnectionViewModel>();
});

您仍然可以将List<PTConnection>以及大多数其他集合类型映射到List<PTConnectionViewModel>.

You can still map a List<PTConnection> to a List<PTConnectionViewModel> just fine, as well as most other collection types.

这篇关于具有实体框架的自动映射器，初始化错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！