建立早期绑定关系

Question

当我将注释链接到特定实体时，而不是像这样创建关系：

var associateRequest = new AssociateRequest
{
    Target = new EntityReference(SalesOrder.EntityLogicalName, salesOrderGuid),
    RelatedEntities = new EntityReferenceCollection
    {
        new EntityReference(Annotation.EntityLogicalName, noteGuid),
    },
    Relationship = new Relationship("SalesOrder_Annotation")
};

是否可以用强类型的方式引用关系：

var associateRequest = new AssociateRequest
{
    Target = new EntityReference(SalesOrder.EntityLogicalName, salesOrderGuid),
    RelatedEntities = new EntityReferenceCollection
    {
        new EntityReference(Annotation.EntityLogicalName, noteGuid)
    },
    Relationship = SalesOrder.Relationships.SalesOrder_Annotation // <----- ???
};

这类似于能够在开发时获取逻辑名称：

SalesOrder.EntityLogicalName

我们能否以同样的方式引用具体的 1:N 关系：

SalesOrder.Relationships.SalesOrder_Annotation

Answer 1

如果您使用 SDK 中提供的标准 CrmSvcUtil.exe 应用程序 (\SDK\Bin\CrmSvcUtil.exe) 生成代码，则您要查找的值存储在代码属性 RelationshipSchemaNameAttribute 中。我已经使用 SDK (\SDK\SampleCode\CS\HelperCode\MyOrganizationCrmSdkTypes.cs) 中提供的早期绑定实体类文件在控制台应用程序中验证了此代码。

按如下方式调用该方法（根据您的示例）：

var relationship = GetRelationship<SalesOrder>(nameof(SalesOrder.SalesOrder_Annotation))

或者如果你想返回实际的字符串值：

var relationshipName = GetRelationshipSchemaName<SalesOrder>(nameof(SalesOrder.SalesOrder_Annotation))

将此代码添加到应用程序中的帮助程序类中：

public static string GetRelationshipSchemaName<T>(string relationshipPropertyName) where T:Entity
{
    return typeof (T).GetProperties()
        .FirstOrDefault(x => x.Name == relationshipPropertyName)
        .GetCustomAttributes()
        .OfType<RelationshipSchemaNameAttribute>()
        .FirstOrDefault()
        ?.SchemaName;            
}

public static Relationship GetRelationship<T>(string relationshipPropertyName) where T : Entity
{
    return new Relationship(typeof(T).GetProperties()
        .FirstOrDefault(x => x.Name == relationshipPropertyName)
        .GetCustomAttributes()
        .OfType<RelationshipSchemaNameAttribute>()
        .FirstOrDefault()
        ?.SchemaName);
}

这是您更新后的代码的样子：

var associateRequest = new AssociateRequest
                                   {
                                       Target =
                                           new EntityReference(
                                               SalesOrder.EntityLogicalName,
                                               salesOrderGuid),
                                       RelatedEntities =
                                           new EntityReferenceCollection
                                               {
                                                   new EntityReference(
                                                       Annotation
                                                           .EntityLogicalName,
                                                       noteGuid)
                                               },
                                       Relationship = GetRelationship<SalesOrder>(nameof(SalesOrder.SalesOrder_Annotation)) ///////////????
                                   };

Answer 2

再想一想，我的 t4 模板答案似乎有点矫枉过正
您可以使用表达式树和扩展方法来轻松获得所需的内容

using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;

namespace ConsoleApplication9
{
    internal class Program
    {
        private static void Main(string[] args)
        {
            Relationship r = new Class1().GetRelationShip(s => s.RelationShipProperty);
            Console.WriteLine(r.Name);
            System.Console.ReadLine();
        }
    }

    public static class MyExtention
    {
        public static Relationship GetRelationShip<T, TProperty>(this T t, Expression<Func<T, TProperty>> expression)
        {
            return new Relationship(((expression.Body as MemberExpression).Member as PropertyInfo)
                    .GetCustomAttributes(typeof(RelationshipAttribute))
                    .Select(a=>(RelationshipAttribute)a)
                    .First().Name
                    );
        }
    }

    public class RelationshipAttribute : System.Attribute
    {
        public string Name { get; set; }

        public RelationshipAttribute(string name)
        {
            Name = name;
        }
    }

    public class Relationship
    {
        public string Name { get; set; }

        public Relationship(string name)
        {
            Name = name;
        }
    }

    public class Class1
    {
        [Relationship("RelationShipA")]
        public List<int> RelationShipProperty { get; set; }
    }
}

Answer 3

根据您的说法，您生成的类有一个带有关系名称的属性。
您所需要的只是一个 t4 模板，它可以为您的关系生成一个具有强类型属性的类

假设您的项目中有以下代码

namespace ConsoleApplication9
{
    public class RelationshipAttribute : System.Attribute
    {
        public string Name { get; set; }

        public RelationshipAttribute(string name) { Name = name; }
    }

    [Relationship("RelationShipA")]
    public class Class1 { }

    [Relationship("RelationShipB")]
    public class Class2 { }

    [Relationship("RelationShipC")]
    public class Class3 { }

}

这个模板

<#@ template debug="false" hostspecific="false" language="C#" #>
<#@ assembly name="System" #>
<#@ assembly name="System.Core" #>
<#@ assembly name="$(TargetPath)" #>
<#@ import namespace="System.Collections.Generic" #>
<#@ import namespace="System.Linq" #>
<#@ import namespace="System" #>
<#@ import namespace="System.Reflection" #>
<#@ output extension=".cs" #>

namespace YourNameSpace
{
   public static class Relationships
   {
      <# 
         var types = typeof(ConsoleApplication9.RelationshipAttribute).Assembly
                     .GetTypes()
                     .Select(t => new { t.Name, Value = t.GetCustomAttribute(typeof(ConsoleApplication9.RelationshipAttribute)) })
                     .Where(t => t.Value != null)
                     .Select(t=> new { t.Name,Value= ((ConsoleApplication9.RelationshipAttribute)t.Value).Name })
                     .ToList();

                 foreach (var attr in types)
  { #>
 public static class  <#=  attr.Name #>
        {
            public const string <#=  attr.Value #> = "<#=  attr.Value #>";
        }
      <# }

  #>}
}

将生成以下 .cs 文件

namespace YourNameSpace
{
   public static class Relationships
   {
         public static class  Class1
         {
           public const string RelationShipA = "RelationShipA";
         }
         public static class  Class2
         {
           public const string RelationShipB = "RelationShipB";
         }
         public static class  Class3
         {
           public const string RelationShipC = "RelationShipC";
         }
   }
}

那么你就可以像这样使用它了

Relationship = new Relationship(Relationships.Class1.RelationShipA )

Answer 4

我不确定我的问题是否正确。 C# 6.0 特性 nameof(...) 不会做这件事吗？

即。

new Relationship(nameof(RelationshipSalesOrder.Relationships.SalesOrder_Annotation));

Answer 5

XrmToolBox 中的 Early Bound Generator 将为您生成这些关系名称。

public static class Fields
{
    public const string AccountId = "accountid";
    public const string AccountRoleCode = "accountrolecode";
    public const string Address1_AddressId = "address1_addressid";
    // *** SNIP *** 
    public const string YomiLastName = "yomilastname";
    public const string YomiMiddleName = "yomimiddlename";
    public const string business_unit_contacts = "business_unit_contacts";
    public const string contact_customer_accounts = "contact_customer_accounts";
    public const string Referencingcontact_customer_contacts = "contact_customer_contacts";
    public const string Referencingcontact_master_contact = "contact_master_contact";
    public const string contact_owning_user = "contact_owning_user";
    public const string lk_contact_createdonbehalfby = "lk_contact_createdonbehalfby";
    public const string lk_contact_modifiedonbehalfby = "lk_contact_modifiedonbehalfby";
    public const string lk_contactbase_createdby = "lk_contactbase_createdby";
    public const string lk_contactbase_modifiedby = "lk_contactbase_modifiedby";
    public const string system_user_contacts = "system_user_contacts";
}