Entity framework core 脚手架DbContext在尝试复数化时返回System.ArgumentNullException:参数名称：EFCore 2.0中的ProposeIdentifier

当我运行命令时，Scaffold DbContext“Server=localhost；Database=MyDatabase；integratedsecurity=true”Microsoft.EntityFrameworkCore.SqlServer

我得到一个错误：

System.ArgumentNullException: Value cannot be null.
Parameter name: proposedIdentifier
   at Microsoft.EntityFrameworkCore.Utilities.Check.NotEmpty(String value, String parameterName)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.CSharpUtilities.Uniquifier(String proposedIdentifier, ICollection`1 existingIdentifiers)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.CSharpUtilities.GenerateCSharpIdentifier(String identifier, ICollection`1 existingIdentifiers, Func`2 singularizePluralizer, Func`3 uniquifier)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.CSharpUtilities.GenerateCSharpIdentifier(String identifier, ICollection`1 existingIdentifiers, Func`2 singularizePluralizer)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.CSharpNamer`1.GetName(T item)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.CSharpUniqueNamer`1.GetName(T item)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.GetEntityTypeName(DatabaseTable table)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.VisitTable(ModelBuilder modelBuilder, DatabaseTable table)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.VisitTables(ModelBuilder modelBuilder, ICollection`1 tables)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.VisitDatabaseModel(ModelBuilder modelBuilder, DatabaseModel databaseModel)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.CreateFromDatabaseModel(DatabaseModel databaseModel, Boolean useDatabaseNames)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.Create(String connectionString, IEnumerable`1 tables, IEnumerable`1 schemas, Boolean useDatabaseNames)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.ModelScaffolder.Generate(String connectionString, IEnumerable`1 tables, IEnumerable`1 schemas, String projectPath, String outputPath, String rootNamespace, String contextName, Boolean useDataAnnotations, Boolean overwriteFiles, Boolean useDatabaseNames)
   at Microsoft.EntityFrameworkCore.Design.Internal.DatabaseOperations.ScaffoldContext(String provider, String connectionString, String outputDir, String dbContextClassName, IEnumerable`1 schemas, IEnumerable`1 tables, Boolean useDataAnnotations, Boolean overwriteFiles, Boolean useDatabaseNames)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.ScaffoldContextImpl(String provider, String connectionString, String outputDir, String dbContextClassName, IEnumerable`1 schemaFilters, IEnumerable`1 tableFilters, Boolean useDataAnnotations, Boolean overwriteFiles, Boolean useDatabaseNames)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.ScaffoldContext.<>c__DisplayClass0_1.<.ctor>b__0()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.<>c__DisplayClass3_0`1.<Execute>b__0()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)
Value cannot be null.
Parameter name: proposedIdentifier.

System.ArgumentNullException:值不能为null。
参数名称：ProposeIdentifier
位于Microsoft.EntityFrameworkCore.Utilities.Check.NotEmpty（字符串值，字符串参数名称）
位于Microsoft.EntityFrameworkCore.Scaffolding.Internal.CSharpUtilities.Uniquifier（字符串ProposeIdentifier，ICollection`1现有标识符）
位于Microsoft.EntityFrameworkCore.Scaffolding.Internal.CSharpUtilities.GenerateCSharpIdentifier（字符串标识符、ICollection`1现有标识符、Func`2 SingularizePlluralizer、Func`3 uniquifier）
位于Microsoft.EntityFrameworkCore.Scaffolding.Internal.CSharpUtilities.GenerateCSharpIdentifier（字符串标识符，ICollection`1现有标识符，Func`2 SingularizePlluralizer）
位于Microsoft.EntityFrameworkCore.Scaffolding.Internal.CSharpNamer`1.GetName（T项）
位于Microsoft.EntityFrameworkCore.Scaffolding.Internal.CSharpUniqueNamer`1.GetName（T项）
位于Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.GetEntityTypeName（数据库表）
位于Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.VisitTable（ModelBuilder ModelBuilder，DatabaseTable表）
位于Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.VisitTables（ModelBuilder ModelBuilder，ICollection`1表）
位于Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.VisitDatabaseModel（ModelBuilder ModelBuilder，DatabaseModel DatabaseModel DatabaseModel）
位于Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.CreateFromDatabaseModel（DatabaseModel DatabaseModel，布尔useDatabaseNames）
位于Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.Create（字符串连接字符串、IEnumerable`1表、IEnumerable`1模式、布尔useDatabaseNames）
位于Microsoft.EntityFrameworkCore.Scaffolding.Internal.ModelScaffolder.Generate（字符串连接字符串、IEnumerable`1表、IEnumerable`1架构、字符串项目路径、字符串输出路径、字符串根命名空间、字符串contextName、布尔useDataAnnotations、布尔重写文件、布尔useDatabaseNames）
位于Microsoft.EntityFrameworkCore.Design.Internal.DatabaseOperations.ScaffoldContext（字符串提供程序、字符串连接字符串、字符串输出目录、字符串dbContextClassName、IEnumerable`1模式、IEnumerable`1表、布尔useDataAnnotations、布尔UseOverwriteFile、布尔UseDatabaseName）
位于Microsoft.EntityFrameworkCore.Design.OperationExecutor.ScaffoldContextImpl（字符串提供程序、字符串连接字符串、字符串输出目录、字符串dbContextClassName、IEnumerable`1 schemaFilters、IEnumerable`1表格过滤器、布尔useDataAnnotations、布尔重写文件、布尔useDatabaseNames）
在Microsoft.EntityFrameworkCore.Design.OperationExecutor.ScaffoldContext.c__DisplayClass0_1.b_0（）中
在Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.c__DisplayClass3_0`1.b__0（）中
位于Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute（操作）
值不能为null。
参数名称：ProposeIdentifier。

在我的启动项目中，我有：

public class CustomPluralizerDesignTimeServices : IDesignTimeServices
{
    public void ConfigureDesignTimeServices(IServiceCollection services)
    {
        services.AddSingleton<IPluralizer, HumanizerToIPluralizerAdapter>();
    }
}

public class HumanizerToIPluralizerAdapter : IPluralizer
{
    public string Pluralize(string name) => name.Pluralize();

    public string Singularize(string name) => name.Singularize();
}

公共类CustomPlularizerDesignTimeServices:IDesignTimeServices
{
public void配置DesignTimeServices（iSeries收集服务）
{
services.AddSingleton（）；
}
}
公共类HumanizerToIPluralizerAdapter:IPluralizer
{
公共字符串Pluralize（字符串名称）=>name.Pluralize（）；
公共字符串Singularize（字符串名称）=>name.Singularize（）；
}

当我删除此代码时，脚手架工作正常

依赖项：

• 数据访问项目（.NET标准2.0）
  • Microsoft.EntityFrameworkCore.SqlServer 2.0
  • Microsoft.EntityFrameworkCore.Tools
  • Microsoft.VisualStudio.Web.CodeGeneration.Design
• 启动项目（.NET CORE 2.0）
  • Microsoft.AspNetCore.All

---

看起来像是您的

IPluralizer

实现中的一个bug。确保它没有为某些值返回null或空字符串。

Microsoft.EntityFrameworkCore.SqlServer

您不需要包含此项，除非您同时拥有

EF 6

和

EF CORE

nuget软件包。如果两个都安装了，除非您绝对需要

EF 6

的原因，否则在我删除参数时，必须将其指定为package manager控制台中的用户输入。有关依赖项，请参见我的编辑