menu
public class Menu
{ /// <summary>
/// id
/// </summary>
[Key, DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity), JsonIgnore]
public int id { set; get; }
/// <summary>
/// 名称
/// </summary>
[MaxLength(100), Required]
public string name { set; get; }
/// <summary>
/// 属性
/// </summary>
public virtual Meta meta{ get; set; }
}
meta
public class Meta
{
/// <summary>
/// 名称
/// </summary>
[MaxLength(150), Required]
public string title { set; get; }
/// <summary>
/// 图标
/// </summary>
[MaxLength(150)]
public string icon { set; get; }
/// <summary>
/// 隐藏
/// </summary>
public bool? hidden { set; get; }
}
//EF [Owned] 已拥有
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Menu>().OwnsOne(p => p.meta);
}
//问题 主键ID不自增
id = table.Column<int>(type: "int", nullable: false)
//丢失
.Annotation("MySQL:ValueGenerationStrategy", MySQLValueGenerationStrategy.IdentityColumn),
//采用新的方法 属性 Json转对象
modelBuilder
.Entity<Menu>()
.Property(e => e.meta)
.HasConversion(
v => ObjectToJson(v), // 进入 Json转对象
v => JsonToObject<Meta>(v), //返回 Json转对象
new ValueComparer<Meta>(
(c1, c2) => ObjectToJson(c1) == ObjectToJson(c2),
c => c == null ? 0 : ObjectToJson(c).GetHashCode(),
c => c)
);
/// <summary>
/// 对象转json
/// </summary>
/// <param name="obj">对象</param>
/// <returns></returns>
protected string ObjectToJson(object obj)
{
string result = null;
try
{
result = JsonSerializer.Serialize(obj);
}
catch { }
return result;
}
/// <summary>
/// 把Json文本转为实体
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="input"></param>
/// <returns></returns>
protected T JsonToObject<T>(string input)
{
try
{
return JsonSerializer.Deserialize<T>(input);
}
catch
{
return default(T);
}
}
EF OwnsOne 主键不自增的相关教程结束。
