EF CORE中复杂类型的映射

Posted 2021-03-07 qinqoushui

实体映射时，遇到复杂类型，可选择下述方法处理：

1. NotMapped，跳过映射
2. 在复杂类型上声明 [Owned],但仅限该复杂类型是全部由简单值类型组成的
3. 自定义序列化方法

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示例： IPInfo使用了owned，对IPEndPoint使用自定义序列化，对VersionInfo使用JSON序列化

@@@code

public class Controller : IController

????{

????public int SN { get; set; }

???? ?

????public IPInfo IPInfo { get; set; } = IPInfo.Default;

???? ?

????[Column(TypeName = "string")]

????public VersionInfo VersionInfo { get; set; } = VersionInfo.Default;

???? [Column(TypeName = "string")]

????public System.Net.IPEndPoint ServerIPEndPoint { get; set; } = new System.Net.IPEndPoint(System.Net.IPAddress.Any, 0);

???? ?

????public DateTime Time { get; set; } = DateTime.Now;

}

?

[Owned]

????public class IPInfo

????{

????public static IPInfo Default { get; } = new IPInfo()

????{

????????IP="192.168.0.254"

????};

????public string IP { get; set; }

?

????public ushort Port { get; set; } = 60000;

????public string Mac { get; set; }

????public string Mask { get; set; } = "255.255.255.0";

????public string Gateway { get; set; } = "192.168.0.1";

????public bool Force { get; set; }

?

????}

@@#

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自定义序列化

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@@@code

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public class IPEndPointConverter : ValueConverter<System.Net.IPEndPoint, string>

????{

????public IPEndPointConverter(ConverterMappingHints mappingHints = null)

????????: base(

???????? v => v.ToString(),

???????? v => System.Net.IPEndPoint.Parse(v),

???????? mappingHints)

????{

????}

?

????public static ValueConverterInfo DefaultInfo { get; }

????????= new ValueConverterInfo(typeof(System.Net.IPEndPoint), typeof(string), i => new IPEndPointConverter(i.MappingHints));

????}

????public class JsonConverter<T> : ValueConverter<T, string>

????{

????public JsonConverter() : this(null)

????{

?

????}

???? ?

????public JsonConverter(ConverterMappingHints mappingHints = null)

????????: base(

???????? v => v.SerializeObject(),

???????? v => v.Deserialize<T>(),

???????? mappingHints)

????{

????}

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????public static ValueConverterInfo DefaultInfo { get; }

????????= new ValueConverterInfo(typeof(T), typeof(string), i => new JsonConverter<T>(i.MappingHints));

}

?

protected override void OnModelCreating(ModelBuilder modelBuilder)

????{

????????base.OnModelCreating(modelBuilder);

????????void aa<T>() where T : class

????????{

????????modelBuilder.Entity<T>().ToTable(typeof(T).Name.ToLower());

????????}

???????? ?

????????aa<User>();

????????aa<Device>();

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????????foreach (var entityType in modelBuilder.Model.GetEntityTypes())

????????{

?

????????foreach (var property in entityType.GetProperties())

????????{

????????????if (property.ClrType.IsValueType && !property.ClrType.IsGenericType)

????????????continue;

?

????????????switch (property.ClrType.Name)

????????????{

????????????case nameof(System.Net.IPEndPoint):

????????????????property.SetValueConverter(new IPEndPointConverter()); //演示 owned效果，仅限复杂类型是由简单类型组成的，没有内嵌复杂类型

????????????????break;

????????????case nameof(String):

????????????????break;

????????????default:

????????????????Type genType = typeof(JsonConverter<>).MakeGenericType(property.ClrType);

????????????????ValueConverter obj = Activator.CreateInstance(genType) as ValueConverter;

????????????????property.SetValueConverter(obj);

???? ???????? break;

????????????}

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????????}

????????}

?

????}

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@@#

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