我正在使用ASP.NET Core 2.1中的WebAPI进行我的副项目。我正在使用Entity Framework Core 2.1。
我有一个用户：
public class User : Account
{
public UInt64 UserEmail { get; protected set; }
public UserImage UserImage { get; set; }
public virtual ICollection<Recipe> Recipes { get; set; }
public User() { }
public User(string nick, UInt64 login, byte[] salt, byte[] passwordHash,
string restoreKey, UInt64 userEmail) : base(nick, login, salt, passwordHash, restoreKey)
{
UserEmail = userEmail;
Role = "user";
}
public void Update(UInt64 login, UInt64 userEmail)
{
Login = login;
UserEmail = userEmail;
UpdatedAt = DateTime.UtcNow;
}
public void UpdatePassword(byte[] newPassword)
{
PasswordHash = newPassword;
UpdatedAt = DateTime.UtcNow;
}
}
和UserImage：
public class UserImage : Image
{
public int? UserRef { get; set; }
public virtual User User { get; set; }
public UserImage() : base() { }
public UserImage(string content) : base(content) { }
}
在我的DbContext中，我有这样的事情：
modelBuilder.Entity<User>()
.HasOne(x => x.UserImage)
.WithOne(y => y.User)
.HasForeignKey<UserImage>(y => y.UserRef)
.IsRequired(false);
我的服务中有一个方法返回一个用户的图像：
public async Task<User> GetAsync(int id)
{
var user = await _context.Users.GetById(id)
.Include(x => x.UserImage)
.SingleOrDefaultAsync();
if (user == null)
throw new CorruptedOperationException("Invalid id");
return user;
}
问题是，当我使用Postman获取用户时，我得到了那种响应：
{
"userEmail": 2606810040825320252,
"userImage": {
"userRef": 16,
"user": {
"userEmail": 2606810040825320252,
"recipes": null,
"nick": "MadBear123",
"login": 10458175107962595193,
"salt": "Fv/S1pnpu1u0RA6RxE1wfwCmqhbkb0Fu0W2sOuFgv//PHyizyPtmuaX8OtYkCgSJPlKMGmE2qFgg2rgs70Ee9bbMU26iVhtIApqV/Zxac54P9EXBvgkAXede3YHzSPzHkvGz3WchUUDIQqHF+EmdvPT9KuYR1Djgywxh0bDbSJk=",
"passwordHash": "Yk5S3jutaKJpwSQoRH0nk2At3nYL/Wzi+8QGRFOZuByi54o+YJHuhPYRMMSG3Vmimv1UMRWe+VA8ym2xQxoEJA==",
"role": "user",
"restoreKey": "Vub!@g17@kcP",
"id": 16,
"createdAt": "2018-10-14T11:11:43.9902857",
"updatedAt": "2018-10-14T11:11:43.990384"
},
"imageContent": "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",
"id": 10,
"createdAt": "2018-10-16T05:45:42.4644513",
"updatedAt": "2018-10-16T05:45:42.4645292"
},
"recipes": null,
"nick": "MadBear123",
"login": 10458175107962595193,
"salt": "Fv/S1pnpu1u0RA6RxE1wfwCmqhbkb0Fu0W2sOuFgv//PHyizyPtmuaX8OtYkCgSJPlKMGmE2qFgg2rgs70Ee9bbMU26iVhtIApqV/Zxac54P9EXBvgkAXede3YHzSPzHkvGz3WchUUDIQqHF+EmdvPT9KuYR1Djgywxh0bDbSJk=",
"passwordHash": "Yk5S3jutaKJpwSQoRH0nk2At3nYL/Wzi+8QGRFOZuByi54o+YJHuhPYRMMSG3Vmimv1UMRWe+VA8ym2xQxoEJA==",
"role": "user",
"restoreKey": "Vub!@g17@kcP",
"id": 16,
"createdAt": "2018-10-14T11:11:43.9902857",
"updatedAt": "2018-10-14T11:11:43.990384"
}
就像你可以看到我得到一个用户的图像，在这个图像中我得到（再次）这个用户。我想得到这样的回应：
{
"userEmail": 2606810040825320252,
"userImage": {
"userRef": 16,
"user": null,
"imageContent": "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",
"id": 10,
"createdAt": "2018-10-16T05:45:42.4644513",
"updatedAt": "2018-10-16T05:45:42.4645292"
},
"recipes": null,
"nick": "MadBear123",
"login": 10458175107962595193,
"salt": "Fv/S1pnpu1u0RA6RxE1wfwCmqhbkb0Fu0W2sOuFgv//PHyizyPtmuaX8OtYkCgSJPlKMGmE2qFgg2rgs70Ee9bbMU26iVhtIApqV/Zxac54P9EXBvgkAXede3YHzSPzHkvGz3WchUUDIQqHF+EmdvPT9KuYR1Djgywxh0bDbSJk=",
"passwordHash": "Yk5S3jutaKJpwSQoRH0nk2At3nYL/Wzi+8QGRFOZuByi54o+YJHuhPYRMMSG3Vmimv1UMRWe+VA8ym2xQxoEJA==",
"role": "user",
"restoreKey": "Vub!@g17@kcP",
"id": 16,
"createdAt": "2018-10-14T11:11:43.9902857",
"updatedAt": "2018-10-14T11:11:43.990384"
}
或类似的东西。我尝试使用Include（）和（或没有）虚拟方式，但我最终得到了这个。
UPDATE
GetById（）的定义：
public static IQueryable<User> GetById(this IQueryable<User> value,int id)
=> value.Where(x => x.Id == id);
你可以在GitHub找到完整的项目。我正在分支MB#20。
对于循环引用，您无法在EF Core中控制它。
对于一般处理，我们在Startup.cs中配置它
.AddJsonOptions(options =>
{
options.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json
.ReferenceLoopHandling.Ignore;
options.SerializerSettings.ContractResolver =
new CamelCasePropertyNamesContractResolver();
});
用例：
var user = await _userService.GetAsync(id);
return Ok(user);
对于你的问题，你在user返回之前修改了return Ok(user.ShapeData(fields));，这使得JsonSerialize无法知道它的循环引用。
对于变通方法，在转换为ExpandoObject之前，处理循环引用，如
public static ExpandoObject ShapeData<TSource>(this TSource source, string fields)
{
if (source == null)
{
throw new ArgumentNullException("source");
}
var result =JsonConvert.SerializeObject(source, new JsonSerializerSettings{
ReferenceLoopHandling = ReferenceLoopHandling.Ignore
} );
source = JsonConvert.DeserializeObject<TSource>(result);
var dataShapedObject = new ExpandoObject();
//your rest code
return dataShapedObject;
}
更新
对于UserImage中的null，它是由您将属性指定为public string ImageContent { get; protected set; }引起的。
尝试自定义DefaultContractResolver以反序列化受保护的属性。
IncludePrivateStateContractResolver.cs
public class IncludePrivateStateContractResolver : DefaultContractResolver
{
protected override List<MemberInfo> GetSerializableMembers(Type objectType)
{
const BindingFlags BindingFlags = BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public;
var properties = objectType.GetProperties(BindingFlags);//.Where(p => p.HasSetter() && p.HasGetter());
var fields = objectType.GetFields(BindingFlags);
var allMembers = properties.Cast<MemberInfo>().Union(fields);
return allMembers.ToList();
}
protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
{
var prop = base.CreateProperty(member, memberSerialization);
if (!prop.Writable)
{
var property = member as PropertyInfo;
if (property != null)
{
prop.Writable = property.HasSetter();
}
else
{
var field = member as FieldInfo;
if (field != null)
{
prop.Writable = true;
}
}
}
if (!prop.Readable)
{
var field = member as FieldInfo;
if (field != null)
{
prop.Readable = true;
}
}
return prop;
}
}
public static class TypeExtensions
{
public static bool HasSetter(this PropertyInfo property)
{
//In this way we can check for private setters in base classes
return property.DeclaringType.GetMethods(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public)
.Any(m => m.Name == "set_" + property.Name);
}
public static bool HasGetter(this PropertyInfo property)
{
//In this way we can check for private getters in base classes
return property.DeclaringType.GetMethods(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public)
.Any(m => m.Name == "get_" + property.Name);
}
}
用例：
public static ExpandoObject ShapeData<TSource>(this TSource source, string fields)
{
var soureType = source.GetType();
if (source == null)
{
throw new ArgumentNullException("source");
}
var serializeSettings = new JsonSerializerSettings{
ReferenceLoopHandling = ReferenceLoopHandling.Ignore
};
var deserializeSettings = new JsonSerializerSettings{
ContractResolver = new IncludePrivateStateContractResolver()
};
var result =JsonConvert.SerializeObject(source, serializeSettings );
var castType = JsonConvert.DeserializeObject<TSource>(result, deserializeSettings);
var dataShapedObject = new ExpandoObject();
我设法解决了我的问题。我将模型属性中的所有私有设置器更改为公共使用的Tao Zhou原始答案。
我的ShapeData方法：
public static ExpandoObject ShapeData<TSource>(this TSource source, string fields)
{
if (source == null)
{
throw new ArgumentNullException("source");
}
var result = JsonConvert.SerializeObject(source, new JsonSerializerSettings
{
ReferenceLoopHandling = ReferenceLoopHandling.Ignore
});
source = JsonConvert.DeserializeObject<TSource>(result);
var dataShapedObject = new ExpandoObject();
// rest of my code
}
用户：
public class User : Account
{
public UInt64 UserEmail { get; set; }
public UserImage UserImage { get; set; }
public virtual ICollection<Recipe> Recipes { get; set; }
// rest of the code
}
UserImage：
public class UserImage : Image
{
public int? UserRef { get; set; }
public virtual User User { get; set; }
public UserImage() : base() { }
public UserImage(string content) : base(content) { }
}
返回数据的示例：
{
"userEmail": 2606810040825320252,
"userImage": {
"userRef": 16,
"user": null,
"imageContent": "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",
"id": 10,
"createdAt": "2018-10-16T05:45:42.4644513",
"updatedAt": "2018-10-16T05:45:42.4645292"
},
"recipes": null,
"nick": "MadBear123",
"login": 10458175107962595193,
"salt": "Fv/S1pnpu1u0RA6RxE1wfwCmqhbkb0Fu0W2sOuFgv//PHyizyPtmuaX8OtYkCgSJPlKMGmE2qFgg2rgs70Ee9bbMU26iVhtIApqV/Zxac54P9EXBvgkAXede3YHzSPzHkvGz3WchUUDIQqHF+EmdvPT9KuYR1Djgywxh0bDbSJk=",
"passwordHash": "Yk5S3jutaKJpwSQoRH0nk2At3nYL/Wzi+8QGRFOZuByi54o+YJHuhPYRMMSG3Vmimv1UMRWe+VA8ym2xQxoEJA==",
"role": "user",
"restoreKey": "Vub!@g17@kcP",
"id": 16,
"createdAt": "2018-10-14T11:11:43.9902857",
"updatedAt": "2018-10-14T11:11:43.990384"
}