.NET6升级至.NET7 RC1时泛型类型约束违反问题排查

问题详情 #

将WinForms项目从.NET6升级至.NET7 RC1，修改目标框架并更新所有NuGet包后，运行项目时触发以下错误：

泛型参数[0]“System.Int32”不符合“T MaxFloatT”的类型约束。

错误出现在以下代码行：

System.Windows.Forms.Application.Run(host.Services.GetRequiredService<XtraMain>());

Program.cs 代码 #

[STAThread]
private static void Main()
{
    WindowsFormsSettings.ForceDirectXPaint();
    DevExpress.UserSkins.BonusSkins.Register();
    DevExpress.Skins.SkinManager.EnableFormSkins();
    System.Windows.Forms.Application.EnableVisualStyles();
    System.Windows.Forms.Application.SetCompatibleTextRenderingDefault(false);
    System.Windows.Forms.Application.SetHighDpiMode(HighDpiMode.SystemAware);
    
    using IHost host = CreateHostBuilder().Build();
    System.Windows.Forms.Application.Run(host.Services.GetRequiredService<XtraMain>());
}

private static IHostBuilder CreateHostBuilder() => Host.CreateDefaultBuilder()
        .ConfigureAppConfiguration((context, builder) =>
        {
            builder
            .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
            .AddJsonFile($"appsettings.{context.HostingEnvironment.EnvironmentName}.json", optional: true)
            .AddEnvironmentVariables(); 
        })
        .ConfigureServices((context, services) =>
        {
            services.AddScoped<XtraMain>();
            services.AddPersistenceServices(context.Configuration);
            services.AddApplicationServices();
            services.AddSingleton<IFormFactory, FormFactory>();
        });

堆栈跟踪信息 #

在 System.RuntimeType.ValidateGenericArguments(MemberInfo definition, RuntimeType[] genericArguments, Exception e) 处
在 System.Reflection.RuntimeMethodInfo.MakeGenericMethod(Type[] methodInstantiation) 处
在 AutoMapper.Internal.TypeDetails.<>c__DisplayClass25_1.b__10(MethodInfo extensionMethod) 处
在 System.Linq.Enumerable.WhereSelectArrayIterator2.MoveNext() 处 在 System.Linq.Enumerable.ConcatIterator1.MoveNext() 处
在 System.Linq.Enumerable.d__2313.MoveNext() 处 在 System.Linq.Enumerable.WhereSelectEnumerableIterator2.MoveNext() 处
在 System.Linq.Enumerable.UnionIterator1.MoveNext() 处 在 System.Linq.Enumerable.ConcatIterator1.MoveNext() 处
在 AutoMapper.Internal.TypeDetails.PossibleNames() 处
在 AutoMapper.Internal.TypeDetails.GetMember(String name) 处
在 AutoMapper.Configuration.Conventions.DefaultName.GetMatchingMemberInfo(TypeDetails sourceTypeDetails, Type destType, Type destMemberType, String nameToSearch) 处
在 AutoMapper.Configuration.Conventions.ParentSourceToDestinationNameMapper.GetMatchingMemberInfo(TypeDetails sourceTypeDetails, Type destType, Type destMemberType, String nameToSearch) 处
在 AutoMapper.Configuration.Conventions.DefaultMember.MapDestinationPropertyToSource(ProfileMap options, TypeDetails sourceTypeDetails, Type destType, Type destMemberType, String nameToSearch, List1 resolvers, IMemberConfiguration parent, Boolean isReverseMap) 处 在 AutoMapper.Configuration.Conventions.MemberConfiguration.MapDestinationPropertyToSource(ProfileMap options, TypeDetails sourceType, Type destType, Type destMemberType, String nameToSearch, List1 resolvers, Boolean isReverseMap) 处
在 AutoMapper.Configuration.Conventions.NameSplitMember.MapDestinationPropertyToSource(ProfileMap options, TypeDetails sourceType, Type destType, Type destMemberType, String nameToSearch, List1 resolvers, IMemberConfiguration parent, Boolean isReverseMap) 处 在 AutoMapper.Configuration.Conventions.MemberConfiguration.MapDestinationPropertyToSource(ProfileMap options, TypeDetails sourceType, Type destType, Type destMemberType, String nameToSearch, List1 resolvers, Boolean isReverseMap) 处
在 AutoMapper.ProfileMap.MapDestinationPropertyToSource(TypeDetails sourceTypeDetails, Type destType, Type destMemberType, String destMemberName, List1 members, Boolean reverseNamingConventions) 处 在 AutoMapper.TypeMap..ctor(Type sourceType, Type destinationType, ProfileMap profile, Boolean isReverseMap) 处 在 AutoMapper.ProfileMap.BuildTypeMap(IGlobalConfiguration configurationProvider, ITypeMapConfiguration config) 处 在 AutoMapper.ProfileMap.Register(IGlobalConfiguration configurationProvider) 处 在 AutoMapper.MapperConfiguration.Seal() 处 在 AutoMapper.MapperConfiguration..ctor(MapperConfigurationExpression configurationExpression) 处 在 Microsoft.Extensions.DependencyInjection.ServiceCollectionExtensions.<>c.<AddAutoMapperClasses>b__12_2(IServiceProvider sp) 处 在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, RuntimeResolverContext context) 处 在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSiteMain(ServiceCallSite callSite, TArgument argument) 处
在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitRootCache(ServiceCallSite callSite, RuntimeResolverContext context) 处
在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(ServiceCallSite callSite, TArgument argument) 处 在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.Resolve(ServiceCallSite callSite, ServiceProviderEngineScope scope) 处 在 Microsoft.Extensions.DependencyInjection.ServiceProvider.CreateServiceAccessor(Type serviceType) 处 在 System.Collections.Concurrent.ConcurrentDictionary2.GetOrAdd(TKey key, Func2 valueFactory) 处 在 Microsoft.Extensions.DependencyInjection.ServiceProvider.GetService(Type serviceType, ServiceProviderEngineScope serviceProviderEngineScope) 处 在 Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.GetService(Type serviceType) 处 在 Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType) 处 在 Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider) 处 在 Microsoft.Extensions.DependencyInjection.ServiceCollectionExtensions.<>c.<AddAutoMapperClasses>b__12_3(IServiceProvider sp) 处 在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, RuntimeResolverContext context) 处 在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSiteMain(ServiceCallSite callSite, TArgument argument) 处
在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitDisposeCache(ServiceCallSite transientCallSite, RuntimeResolverContext context) 处
在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(ServiceCallSite callSite, TArgument argument) 处 在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, RuntimeResolverContext context) 处 在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSiteMain(ServiceCallSite callSite, TArgument argument) 处
在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitDisposeCache(ServiceCallSite transientCallSite, RuntimeResolverContext context) 处
在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(ServiceCallSite callSite, TArgument argument) 处 在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, RuntimeResolverContext context) 处 在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSiteMain(ServiceCallSite callSite, TArgument argument) 处
在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitRootCache(ServiceCallSite callSite, RuntimeResolverContext context) 处
在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScopeCache(ServiceCallSite callSite, RuntimeResolverContext context) 处
在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(ServiceCallSite callSite, TArgument argument) 处
在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.Resolve(ServiceCallSite callSite, ServiceProviderEngineScope scope) 处
在 Microsoft.Extensions.DependencyInjection.ServiceLookup.DynamicServiceProviderEngine.<>c__DisplayClass2_0.b__0(ServiceProviderEngineScope scope) 处
在 Microsoft.Extensions.DependencyInjection.ServiceProvider.GetService(Type serviceType, ServiceProviderEngineScope serviceProviderEngineScope) 处
在 Microsoft.Extensions.DependencyInjection.ServiceProvider.GetService(Type serviceType) 处
在 Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType) 处
在 Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider) 处
在 SmartWinForm.Program.Main() 位于 C:\Users\MBoua\source\repos\SmartWinForm\SmartWinForm\Program.cs:第30行

排查方向 #

从堆栈跟踪可以看出，错误发生在AutoMapper构建类型映射的过程中，核心是int类型被传入了一个仅允许浮点类型的泛型方法MaxFloat<T>。

• 检查所有AutoMapper配置文件，查找涉及MaxFloat或类似命名的映射规则，确认是否存在整数类型到浮点类型的错误映射配置，或者自定义类型转换器/扩展方法的类型约束是否正确。
• 确认AutoMapper版本与.NET7 RC1的兼容性，尝试升级到AutoMapper的最新稳定版或适配.NET7的预览版本。
• 检查项目中是否存在自定义泛型扩展方法MaxFloat<T>，其类型约束可能仅允许float/double，但被错误地用于int类型。

内容的提问来源于stack exchange，提问作者M.Bouabdallah