如何按返回类型筛选EF过程(例如，通过反射或IL)

本文关键字：反射 IL 例如 返回类型 何按 筛选 EF 过程 | 更新日期: 2023-09-27 17:59:11

让我们假设我们已经通过Entity Framework 6.0从数据库映射了存储过程。我正在尝试根据存储过程的返回类型筛选存储过程，然后使用返回类型通过WPF填充网格。

以下是涉及的查询：

AssemblyName assemblyName = new AssemblyName("CT_EntityDataModel");
Assembly asm = Assembly.Load(assemblyName);
var myMethods = new ObservableCollection<MethodInfo>();
// The LINQ below can be offloaded to an ICommand for reflection using the Command pattern. If the Command pattern will be used much, it really should also be a Singleton.
var q = from t in asm.GetTypes()
        where t.IsClass && t.Namespace == "CT_EntityDataModel"
        && t.Name.Equals("CRMEntities")
        select t.GetMethods();

当我使用反射加载存储过程时，我需要的信息在[MethodInfoInstance]中。ReturnType。UnderlyingSystemType。然而，当我试图获得有关UnderlyingSystemType的更多信息时，我得到的有用信息很少。以下是即时窗口的结果：

j.ReturnType.UnderlyingSystemType
{Name = "ObjectResult`1" FullName = "System.Data.Entity.Core.Objects.ObjectResult`1[[CT_EntityDataModel.PROC_RE_ReadImportInvest_Result, CT_EntityDataModel, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]"}
    [System.RuntimeType]: {Name = "ObjectResult`1" FullName = "System.Data.Entity.Core.Objects.ObjectResult`1[[CT_EntityDataModel.PROC_RE_ReadImportInvest_Result, CT_EntityDataModel, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]"}
    base: {Name = "ObjectResult`1" FullName = "System.Data.Entity.Core.Objects.ObjectResult`1[[CT_EntityDataModel.PROC_RE_ReadImportInvest_Result, CT_EntityDataModel, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]"}
    Assembly: {EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089}
    AssemblyQualifiedName: "System.Data.Entity.Core.Objects.ObjectResult`1[[CT_EntityDataModel.PROC_RE_ReadImportInvest_Result, CT_EntityDataModel, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]], EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"
    Attributes: Public | BeforeFieldInit
    BaseType: {Name = "ObjectResult" FullName = "System.Data.Entity.Core.Objects.ObjectResult"}
    ContainsGenericParameters: false
    DeclaringMethod: 'j.ReturnType.UnderlyingSystemType.DeclaringMethod' threw an exception of type 'System.InvalidOperationException'
    DeclaringType: null
    FullName: "System.Data.Entity.Core.Objects.ObjectResult`1[[CT_EntityDataModel.PROC_RE_ReadImportInvest_Result, CT_EntityDataModel, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]"
    GenericParameterAttributes: 'j.ReturnType.UnderlyingSystemType.GenericParameterAttributes' threw an exception of type 'System.InvalidOperationException'
    GenericParameterPosition: 'j.ReturnType.UnderlyingSystemType.GenericParameterPosition' threw an exception of type 'System.InvalidOperationException'
    GenericTypeArguments: {System.Type[1]}
    GUID: {3cea792c-523d-3659-8584-7b6e3ad1678b}
    HasElementType: false
    IsAbstract: false
    IsAnsiClass: true
    IsArray: false
    IsAutoClass: false
    IsAutoLayout: true
    IsByRef: false
    IsClass: true
    IsCOMObject: false
    IsConstructedGenericType: true
    IsContextful: false
    IsEnum: false
    IsExplicitLayout: false
    IsGenericParameter: false
    IsGenericType: true
    IsGenericTypeDefinition: false
    IsImport: false
    IsInterface: false
    IsLayoutSequential: false
    IsMarshalByRef: false
    IsNested: false
    IsNestedAssembly: false
    IsNestedFamANDAssem: false
    IsNestedFamily: false
    IsNestedFamORAssem: false
    IsNestedPrivate: false
    IsNestedPublic: false
    IsNotPublic: false
    IsPointer: false
    IsPrimitive: false
    IsPublic: true
    IsSealed: false
    IsSecurityCritical: true
    IsSecuritySafeCritical: false
    IsSecurityTransparent: false
    IsSerializable: false
    IsSpecialName: false
    IsUnicodeClass: false
    IsValueType: false
    IsVisible: true
    MemberType: TypeInfo
    Module: {EntityFramework.dll}
    Namespace: "System.Data.Entity.Core.Objects"
    ReflectedType: null
    StructLayoutAttribute: {System.Runtime.InteropServices.StructLayoutAttribute}
    TypeHandle: {System.RuntimeTypeHandle}
    TypeInitializer: null
    UnderlyingSystemType: {Name = "ObjectResult`1" FullName = "System.Data.Entity.Core.Objects.ObjectResult`1[[CT_EntityDataModel.PROC_RE_ReadImportInvest_Result, CT_EntityDataModel, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]"}

UnderlyingSystemType或其他地方是否有方法允许我获取返回类型？

是的，我知道反思的表现很糟糕。一旦我能弄清楚如何做到这一点，我将在IL级别优化代码。如果你告诉我使用ADO。NET或其他什么，我会告诉你，你不知道自己在说什么。仅供参考，我能够直接从数据库中获取返回类型的唯一干净方法是sys.dm_exec_descripte_first_result_set_For_object，它在SQL Server 2012之前的数据库中不包括；此外，dm_exec_descript_first_result_set_for_object并没有从包含动态SQL的过程中提供太多有用的信息。

在最坏的情况下，我想我可以简单地使用正则表达式从MethodInfo实例中获取类型。ReturnType。UnderlyingSystemType。FullName，看起来像这样：

"System.Data.Entity.Core.Objects.ObjectResult`1[[CT_EntityDataModel.PROC_ReadImportInvest_Result，CT_EntityDataModel，版本=1.0.0.0，区域性=中性，PublicKeyToken=null]]"

如果我查看类型PROC_CT_ReadImportInvest_Result，它的定义如下：

namespace CT_EntityDataModel
{
    using System;
    public partial class PROC_RE_ReadImportInvest_Result
    {
        public System.DateTime dtDate1 { get; set; }
        public string txtData1 { get; set; }
    }
}

我想要上面FullName值的"PROC_ReadImportInvest_Result"部分。有没有一种不那么难看的方法来获得这种类型，而不是使用Regex来提取它？

谢谢，Devin

[更新（太平洋标准时间2014年4月20日下午5:56）：这是解决这个问题的最终代码]：

    // If these values will be consumed by a ViewModel, then we need to use an ObservableDictionary here.
public  Dictionary<MethodInfo, Type> GetTypesDictionary()
{
    // This is for our ViewModel.
    AssemblyName assemblyName = new AssemblyName("CT_EntityDataModel");
    Assembly asm = Assembly.Load(assemblyName);
    // The LINQ below can be offloaded to an ICommand for reflection.
    var q = from t in asm.GetTypes()
            where t.IsClass && t.Namespace == "CT_EntityDataModel"
            && t.Name.Equals("CRMEntities")
            select t.GetMethods();
    // We need to filter these to only those that return a dataset.
    // q can be offloaded to an IPredicateStrategy that returns only the results that match the strategy.
    return (from i in q
            from j in i
            where j.Name.StartsWith("PROC_") && j.Name.Contains("Global")
            let methodType = j.ReturnType.UnderlyingSystemType
            where methodType.IsGenericType
            let test = j.ReturnType.UnderlyingSystemType.GetGenericArguments()
            where test.Length > 0
            select j).ToDictionary(j => j, j => j.ReturnType.UnderlyingSystemType.GetGenericArguments()[0]);
// We can use a Strategy pattern to encapsulate the ".Name.StartsWith" logic.
// This would make an interesting extension method. 
}

如何按返回类型筛选EF过程(例如，通过反射或IL)

您似乎正在获得通用代理对象。你可以试试这样的东西：

var methodType = [MethodInfoInstance].ReturnType.UnderlyingSystemType;
if(methodType.IsGenericType)
{
    methodType = methodType.GetGenericArguments()[0];
}

PS。我是在头脑中写这篇文章的，所以如果有一些语法错误，请原谅我。

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