批量注册IEntityTypeConfiguration <>实体框架核心

问题描述 投票:19回答:6

好,所以我正在使用具有点网核心和代码优先迁移的实体框架。因此这不是问题,我只是想知道是否有人遇到过更好的方法。

目前,我有许多类似的实体类型配置

public class ExampleEntityConfiguration : IEntityTypeConfiguration<ExampleEntity>
{
   public void Configure(EntityTypeBuilder<ExampleEntity> builder)
   {
      builder.Property(p => p.Id).ValueGeneratedNever();

      // more options here
   }
}

并且我像这样将它们注册在我的dbcontext中

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
  base.OnModelCreating(modelBuilder);

  modelBuilder.ApplyConfiguration(new ExampleEntityConfiguration());

  // lot's more configurations here
}

有人遇到或知道注册所有IEntityTypeConfiguration接口的方法吗?

似乎很多重复的代码可以通过获取配置列表,遍历它们并在上下文中应用来解决。我只是不知道从哪里开始获取存在于特定名称空间中的IEntityTypeConfiguration类的列表。

任何帮助/建议都很好。

c# entity-framework-core
6个回答
20
投票

可以通过这样的反射来完成:

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    base.OnModelCreating(modelBuilder);    
    // get ApplyConfiguration method with reflection
    var applyGenericMethod = typeof(ModelBuilder).GetMethod("ApplyConfiguration", BindingFlags.Instance | BindingFlags.Public);            
    // replace GetExecutingAssembly with assembly where your configurations are if necessary
    foreach (var type in Assembly.GetExecutingAssembly().GetTypes()
        .Where(c => c.IsClass && !c.IsAbstract && !c.ContainsGenericParameters)) 
    {
        // use type.Namespace to filter by namespace if necessary
        foreach (var iface in type.GetInterfaces()) {
            // if type implements interface IEntityTypeConfiguration<SomeEntity>
            if (iface.IsConstructedGenericType && iface.GetGenericTypeDefinition() == typeof(IEntityTypeConfiguration<>)) {
                // make concrete ApplyConfiguration<SomeEntity> method
                var applyConcreteMethod = applyGenericMethod.MakeGenericMethod(iface.GenericTypeArguments[0]);
                // and invoke that with fresh instance of your configuration type
                applyConcreteMethod.Invoke(modelBuilder, new object[] {Activator.CreateInstance(type)});
                break;
            }
        }
    }
}

23
投票

使用EF Core 2.2+,它变得更加简单:

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
   Assembly assemblyWithConfigurations = GetType().Assembly; //get whatever assembly you want
   modelBuilder.ApplyConfigurationsFromAssembly(assemblyWithConfigurations);
}

12
投票

@ Evk的出色著作被进一步封装在可重用的扩展方法中:

 public static class ModelBuilderExtensions
{
    public static void ApplyAllConfigurationsFromCurrentAssembly(this ModelBuilder modelBuilder, Assembly assembly, string configNamespace = "")
    {
        var applyGenericMethods = typeof(ModelBuilder).GetMethods( BindingFlags.Instance | BindingFlags.Public | BindingFlags.FlattenHierarchy);
        var applyGenericApplyConfigurationMethods = applyGenericMethods.Where(m => m.IsGenericMethod && m.Name.Equals("ApplyConfiguration", StringComparison.OrdinalIgnoreCase));
        var applyGenericMethod = applyGenericApplyConfigurationMethods.Where(m=>m.GetParameters().FirstOrDefault().ParameterType.Name== "IEntityTypeConfiguration`1").FirstOrDefault();


        var applicableTypes = assembly
            .GetTypes()
            .Where(c => c.IsClass && !c.IsAbstract && !c.ContainsGenericParameters);

        if (!string.IsNullOrEmpty(configNamespace))
        {
            applicableTypes = applicableTypes.Where(c => c.Namespace == configNamespace);
        }

        foreach (var type in applicableTypes)
        {
            foreach (var iface in type.GetInterfaces())
            {
                // if type implements interface IEntityTypeConfiguration<SomeEntity>
                if (iface.IsConstructedGenericType && iface.GetGenericTypeDefinition() == typeof(IEntityTypeConfiguration<>))
                {
                    // make concrete ApplyConfiguration<SomeEntity> method
                    var applyConcreteMethod = applyGenericMethod.MakeGenericMethod(iface.GenericTypeArguments[0]);
                    // and invoke that with fresh instance of your configuration type
                    applyConcreteMethod.Invoke(modelBuilder, new object[] { Activator.CreateInstance(type) });
                    Console.WriteLine("applied model " + type.Name);
                    break;
                }
            }
        }
    }
}

并且可以这样称呼:

public class ApiDbContext : DbContext
{
    public DbSet<Customer> Customers { get; set; }
    public ApiDbContext(DbContextOptions<ApiDbContext> options) : base(options) { }
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);
        modelBuilder.ApplyAllConfigurationsFromCurrentAssembly("MyRoot.Api.Entities.Configuration");
    }
    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        base.OnConfiguring(optionsBuilder);
    }
}

6
投票

@ Evk的回答有点过时了,不再起作用了,@ paul van bladel的回答是可行的,尽管它包含硬编码的字符串,但我非常讨厌。如果有人有我的感觉,我想以创建静态扩展方法的形式提出我的解决方案:

public static ModelBuilder ApplyAllConfigurationsFromAssembly(
    this ModelBuilder modelBuilder, Assembly assembly)
{   
    var applyGenericMethod = typeof(ModelBuilder)
        .GetMethods(BindingFlags.Instance | BindingFlags.Public)
        .Single(m => m.Name == nameof(ModelBuilder.ApplyConfiguration)
            && m.GetParameters().Count() == 1
            && m.GetParameters().Single().ParameterType.GetGenericTypeDefinition() == typeof(IEntityTypeConfiguration<>));        
    foreach (var type in assembly.GetTypes()
        .Where(c => c.IsClass && !c.IsAbstract && !c.ContainsGenericParameters)) 
    {
        foreach (var iface in type.GetInterfaces())
        {
            if (iface.IsConstructedGenericType && iface.GetGenericTypeDefinition() == typeof(IEntityTypeConfiguration<>)) 
            {
                var applyConcreteMethod = applyGenericMethod.MakeGenericMethod(iface.GenericTypeArguments[0]);
                applyConcreteMethod.Invoke(modelBuilder, new object[] {Activator.CreateInstance(type)});
                break;
            }
        }
    }
}

并且,如果您的配置类与DbContext存储在同一程序集中,则可以按以下方式使用此方法:

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.ApplyAllConfigurationsFromAssembly(GetType().Assembly);           
    base.OnModelCreating(modelBuilder);
}

0
投票

我真的很喜欢为将代码移至扩展方法而提供的答案@paul van bladel。我还需要从其他程序集中调用它,因此我创建了一个枚举并更改了applyTypes来进行不同的设置。

IEnumerable<Type> assemblyTypeList;

switch (pAssemblyMethodType)
{
    case AssemblyMethodType.CallingAssembly:
        assemblyTypeList = Assembly.GetCallingAssembly()
            .GetTypes()
            .Where(c => c.IsClass
                && !c.IsAbstract
                && !c.ContainsGenericParameters);
        break;
    case AssemblyMethodType.ExecutingAssembly:
        assemblyTypeList = Assembly.GetExecutingAssembly()
            .GetTypes()
            .Where(c => c.IsClass
                && !c.IsAbstract
                && !c.ContainsGenericParameters);
        break;
    default:
        throw new ArgumentOutOfRangeException(nameof(pAssemblyMethodType), pAssemblyMethodType, null);
}

0
投票

-DbContext

protected override void OnModelCreating(ModelBuilder builder)
{
    builder.ApplyConfigurationsFromAssembly(Assembly.GetExecutingAssembly());

    base.OnModelCreating(builder);
}
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