地图IReadOnlyDictionary EfCore

Question

我有一个实体，它有一个字典字段，它使用这样的支持字段。

private Dictionary<string, string> _communicationEventProperties = new Dictionary<string, string>();
public IReadOnlyDictionary<string, string> CommunicationEventProperties => new ReadOnlyDictionary<string,string>(_communicationEventProperties);

我已经使用Fluent正确地将它映射到SQL中的JSON。

然而，当我试图调用我的实体时，我会得到以下错误。

System.InvalidCastException: Unable to cast object of type 'System.Collections.ObjectModel.ReadOnlyDictionary`2[System.String,System.String]' to type 'System.Collections.Generic.Dictionary`2[System.String,System.String]'

它似乎没有很好地在类型之间映射。

我不知道为什么没有映射/如何使它正确地映射。

我还将附加整个堆栈跟踪：

[InvalidCastException: Unable to cast object of type 'System.Collections.ObjectModel.ReadOnlyDictionary`2[System.String,System.String]' to type 'System.Collections.Generic.Dictionary`2[System.String,System.String]'.]
   lambda_method(Closure , MaterializationContext ) +1237
   Microsoft.EntityFrameworkCore.Query.EntityLoadInfo.Materialize() +22
   Microsoft.EntityFrameworkCore.Query.Internal.QueryBuffer.GetEntity(IKey key, EntityLoadInfo entityLoadInfo, Boolean queryStateManager, Boolean throwOnNullKey) +201
   Microsoft.EntityFrameworkCore.Query.ExpressionVisitors.Internal.BufferedEntityShaper`1.Shape(QueryContext queryContext, ValueBuffer& valueBuffer) +198
   Microsoft.EntityFrameworkCore.Query.Internal.<BufferlessMoveNext>d__12.MoveNext() +1121
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
   Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.<ExecuteAsync>d__7`2.MoveNext() +174
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
   Microsoft.EntityFrameworkCore.Query.Internal.<MoveNext>d__11.MoveNext() +637
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
   Microsoft.EntityFrameworkCore.Query.Internal.<MoveNext>d__3.MoveNext() +210
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
   System.Linq.<FirstOrDefault_>d__165`1.MoveNext() in D:\a\1\s\Ix.NET\Source\System.Interactive.Async\First.cs:144
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
   Microsoft.EntityFrameworkCore.Query.Internal.<MoveNext>d__3.MoveNext() +243
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
   System.Linq.<MoveNextCore>d__7.MoveNext() in D:\a\1\s\Ix.NET\Source\System.Interactive.Async\Select.cs:106
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
   System.Linq.<MoveNext>d__10.MoveNext() in D:\a\1\s\Ix.NET\Source\System.Interactive.Async\AsyncIterator.cs:109
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
   Microsoft.EntityFrameworkCore.Query.Internal.<MoveNext>d__5.MoveNext() +634
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
   Microsoft.EntityFrameworkCore.Query.Internal.<ExecuteSingletonAsyncQuery>d__21`1.MoveNext() +447
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
   System.Runtime.CompilerServices.TaskAwaiter`1.GetResult() +29
   Metis.Communications.Core.EFCore.Interactions.EmailCommunications.GetEmailCommunicationDetails.<<-ctor>g__EmailCommunicationExists|1>d.MoveNext() in C:\Users\ethalacker\source\repos\Metis\src\Communication\Metis.Communications.Core.EFCore\Interactions\EmailCommunications\GetEmailCommunicationDetails\GetEmailCommunicationDetailsValidator.cs:25
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
   FluentValidation.Validators.<ValidateAsync>d__7.MoveNext() in /home/jskinner/code/FluentValidation/src/FluentValidation/Validators/PropertyValidator.cs:65
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
   System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task) +26
   FluentValidation.Internal.<ValidateAsync>d__66.MoveNext() in /home/jskinner/code/FluentValidation/src/FluentValidation/Internal/PropertyRule.cs:396
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
   FluentValidation.<ValidateAsync>d__14.MoveNext() in /home/jskinner/code/FluentValidation/src/FluentValidation/AbstractValidator.cs:146
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
   System.Runtime.CompilerServices.ConfiguredTaskAwaiter.GetResult() +29
   Metis.SharedKernel.Interactions.<IsValid>d__10.MoveNext() in C:\Users\ethalacker\source\repos\Metis\src\Shared\Metis.SharedKernel\Interactions\InteractionHandler.cs:77
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
   System.Runtime.CompilerServices.TaskAwaiter`1.GetResult() +29
   Metis.SharedKernel.Interactions.<Handle>d__8.MoveNext() in C:\Users\ethalacker\source\repos\Metis\src\Shared\Metis.SharedKernel\Interactions\InteractionHandler.cs:41
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
   MediatR.Pipeline.<Handle>d__2.MoveNext() +260
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
   MediatR.Pipeline.<Handle>d__2.MoveNext() +733
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
   System.Runtime.CompilerServices.TaskAwaiter`1.GetResult() +29
   Metis.Web.Pages.SiteConfiguration.Communications.EmailCommunications.EmailCommunicationDetails.<Page>d__3.MoveNext() in C:\Users\ethalacker\source\repos\Metis\src\Metis.Web\Pages\SiteConfiguration\Communications\EmailCommunications\EmailCommunicationDetails\EmailCommunicationDetailsController.cs:38
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
   System.Web.Mvc.Async.TaskAsyncActionDescriptor.EndExecute(IAsyncResult asyncResult) +97
   System.Web.Mvc.Async.<>c__DisplayClass8_0.<BeginInvokeAsynchronousActionMethod>b__1(IAsyncResult asyncResult) +17
   System.Web.Mvc.Async.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult) +10
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) +32
   System.Web.Mvc.Async.<>c__DisplayClass11_0.<InvokeActionMethodFilterAsynchronouslyRecursive>b__0() +58
   System.Web.Mvc.Async.<>c__DisplayClass11_2.<InvokeActionMethodFilterAsynchronouslyRecursive>b__2() +228
   System.Web.Mvc.Async.<>c__DisplayClass11_2.<InvokeActionMethodFilterAsynchronouslyRecursive>b__2() +228
   System.Web.Mvc.Async.<>c__DisplayClass11_2.<InvokeActionMethodFilterAsynchronouslyRecursive>b__2() +228
   System.Web.Mvc.Async.<>c__DisplayClass11_2.<InvokeActionMethodFilterAsynchronouslyRecursive>b__2() +228
   System.Web.Mvc.Async.<>c__DisplayClass11_2.<InvokeActionMethodFilterAsynchronouslyRecursive>b__2() +228
   System.Web.Mvc.Async.<>c__DisplayClass11_2.<InvokeActionMethodFilterAsynchronouslyRecursive>b__2() +228
   System.Web.Mvc.Async.<>c__DisplayClass11_2.<InvokeActionMethodFilterAsynchronouslyRecursive>b__2() +228
   System.Web.Mvc.Async.<>c__DisplayClass7_0.<BeginInvokeActionMethodWithFilters>b__1(IAsyncResult asyncResult) +10
   System.Web.Mvc.Async.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult) +10
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult) +34
   System.Web.Mvc.Async.<>c__DisplayClass3_6.<BeginInvokeAction>b__4() +35
   System.Web.Mvc.Async.<>c__DisplayClass3_1.<BeginInvokeAction>b__1(IAsyncResult asyncResult) +100
   System.Web.Mvc.Async.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult) +10
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +27
   System.Web.Mvc.<>c.<BeginExecuteCore>b__152_1(IAsyncResult asyncResult, ExecuteCoreState innerState) +11
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +29
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +45
   System.Web.Mvc.<>c.<BeginExecute>b__151_2(IAsyncResult asyncResult, Controller controller) +13
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +22
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +26
   System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +10
   System.Web.Mvc.<>c.<BeginProcessRequest>b__20_1(IAsyncResult asyncResult, ProcessRequestState innerState) +28
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +29
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +28
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
   System.Web.<>c__DisplayClass7_0.<InvokeEndHandler>b__0() +30
   System.Web.StepInvoker.Invoke(Action executionStep) +100
   System.Web.<>c__DisplayClass4_0.<Invoke>b__0() +17
   Microsoft.AspNet.TelemetryCorrelation.TelemetryCorrelationHttpModule.OnExecuteRequestStep(HttpContextBase context, Action step) +64
   System.Web.<>c__DisplayClass284_0.<OnExecuteRequestStep>b__0(Action nextStepAction) +54
   System.Web.StepInvoker.Invoke(Action executionStep) +84
   System.Web.CallHandlerExecutionStep.InvokeEndHandler(IAsyncResult ar) +113
   System.Web.CallHandlerExecutionStep.OnAsyncHandlerCompletion(IAsyncResult ar) +126

Answer 1

我不得不创建一个特殊的json转换器和比较器。在执行IReadOnlyDictionary时，同样可以应用于IReadOnlyList。类将接受属性的类型，然后尝试将其反序列化为字段类型。我有IReadOnlyDictionary和IReadOnlyList的硬编码特例。但是它也可以通过重载(HasJsonConversionWithSerializationType)接受类型。

我还为其他用例添加了一些其他示例。

我的类属性

private Dictionary<string, string> _communicationEventProperties = new Dictionary<string, string>();
public IReadOnlyDictionary<string, string> CommunicationEventProperties => new ReadOnlyDictionary<string,string>(_communicationEventProperties);

private List<TokenValue> _tokenValues = new List<TokenValue>();
public IReadOnlyList<TokenValue> TokenValues => _tokenValues.AsReadOnly();

private List<string> _cCAddresses = new List<string>();
public IReadOnlyList<string> CCAddresses => _cCAddresses.AsReadOnly();

public class TokenValue
{
    public string Key { get; }
    public string Value { get; }

    public TokenValue(string key, string value)
    {
        // using Dawn. Else you can use a normal "?? throw new ArgumentNullException"
        Key = Guard.Argument(key, nameof(Key)).NotNull().NotEmpty().MaxLength(250);
        Value = value;
    }
}

配置文件

using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata.Builders;

namespace Application.EFCore.Configurations
{
    public class MyEntityConfiguration : IEntityTypeConfiguration<MyEntity>
    {
        public void Configure(EntityTypeBuilder<MyEntity> builder)
        {
            ...

            builder.Property(b => b.CommunicationEventProperties)
                .HasJsonConversion();

            builder.Property(b => b.TokenValues)
                .HasJsonConversion();

            builder.Property(b => b.CCAddresses)
                .HasJsonConversion();
            ...
        }
    }
}

Json转换类

using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata.Builders;
using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
using Newtonsoft.Json;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;

public static class BuilderExtensions
{
    public static PropertyBuilder<TProperty> HasJsonConversion<TProperty>(this PropertyBuilder<TProperty> propertyBuilder) where TProperty : class
    {
        var serializationType = GetSerializationTypeByConvention<TProperty>();
        return HasJsonConversionWithSerializationType(propertyBuilder, serializationType);
    }

    public static PropertyBuilder<TProperty> HasJsonConversionWithSerializationType<TProperty, TSerialization>(this PropertyBuilder<TProperty> propertyBuilder)
        where TProperty : class
        where TSerialization : TProperty
        => HasJsonConversionWithSerializationType(propertyBuilder, typeof(TSerialization));

    public static PropertyBuilder<TProperty> HasJsonConversionWithSerializationType<TProperty>(this PropertyBuilder<TProperty> propertyBuilder, Type serializationType) where TProperty : class
    {
        Guard.Argument(serializationType, nameof(serializationType)).NotNull().Require(t => typeof(TProperty).IsAssignableFrom(t), t => $"Must be able to assign {nameof(serializationType)} '{t.FullName}' to <{nameof(TProperty)}> '{typeof(TProperty).FullName}'");            

        var converter = MakeConverter<TProperty>(serializationType);
        var comparer = MakeComparer<TProperty>(serializationType);

        propertyBuilder.HasConversion(converter);
        propertyBuilder.Metadata.SetValueConverter(converter);
        propertyBuilder.Metadata.SetValueComparer(comparer);

        return propertyBuilder;
    }

    private static Type GetSerializationTypeByConvention<TProperty>() where TProperty : class
    {
        var typeIsReadOnlyDictionary = typeof(TProperty).IsGenericType && typeof(TProperty).GetGenericTypeDefinition() == typeof(IReadOnlyDictionary<,>);
        if (typeIsReadOnlyDictionary) return typeof(Dictionary<,>).MakeGenericType(typeof(TProperty).GetGenericArguments());

        var typeIsReadOnlyList = typeof(TProperty).IsGenericType && typeof(TProperty).GetGenericTypeDefinition() == typeof(IReadOnlyList<>);
        if (typeIsReadOnlyList) return typeof(List<>).MakeGenericType(typeof(TProperty).GetGenericArguments());

        return typeof(TProperty);
    }

    private static Microsoft.EntityFrameworkCore.ChangeTracking.ValueComparer<TProperty> MakeComparer<TProperty>(Type serializationType)
            => new Microsoft.EntityFrameworkCore.ChangeTracking.ValueComparer<TProperty>(
                (l, r) => Serialize(l) == Serialize(r),
                v => v == null ? 0 : Serialize(v).GetHashCode(),
                v => Deserialize<TProperty>(Serialize(v), serializationType));

    private static ValueConverter<TProperty, string> MakeConverter<TProperty>(Type serializationType)
        => new ValueConverter<TProperty, string>(
            v => Serialize(v),
            v => Deserialize<TProperty>(v, serializationType));


    private static TProperty Deserialize<TProperty>(string v, Type serializationType)
    {
        if (v == null) return default;
        return (TProperty)JsonConvert.DeserializeObject(v, serializationType);
    }
    private static string Serialize<TProperty>(TProperty v)
        => JsonConvert.SerializeObject(v
            , Formatting.None
            , new JsonSerializerSettings {
                NullValueHandling = NullValueHandling.Ignore
            });
}