所以我在MVC4中创建了一个WebApi项目，并且无法理解JSON输出。我不完全确定这是否是JSON的预期输出，或者我是否做错了。
我有三个表，（pb_Project，pb_Tasks和pb_Priority）。关系如下： 项目可能有许多任务，每个项目可以有一个优先级。
entities http://img705.imageshack.us/img705/9294/stackoverflowentities.png
现在，我收到的输出很奇怪而且不太直观。我不确定这是否是预期的JSON（因为我是全新的）。当我运行网站以检索项目的JSON输出时，我得到以下结果。
[
{
"$id": "1",
"pb_Priority": {
"$id": "2",
"pb_Projects": [
{
"$ref": "1"
},
{
"$id": "3",
"pb_Priority": {
"$ref": "2"
},
"pb_Tasks": [
{
"$id": "4",
"pb_Projects": {
"$ref": "3"
},
"TASK_ID": 3,
"PROJECT_ID": 2,
"USER_ID": 2,
"DUE_DATE": "2012-11-19T00:00:00",
"PRIORITY_ID": 2,
"TASK_NAME": "project 2 task 1",
"DESCRIPTION": "asdf"
}
],
"PROJECT_ID": 2,
"USER_ID": 2,
"NAME": "Project2",
"DESCRIPTION": "project 2 description",
"BUDGET": 1,
"LOCATION": "CANADA",
"START_DATE": "2012-11-18T00:00:00",
"PRIORITY_ID": 1,
"PROJ_SCALE": null,
"NOTES": null
}
],
"PRIORITY_ID": 1,
"PRIORITY_LEVEL": 1
},
"pb_Tasks": [
{
"$id": "5",
"pb_Projects": {
"$ref": "1"
},
"TASK_ID": 1,
"PROJECT_ID": 1,
"USER_ID": 1,
"DUE_DATE": "2012-11-19T00:00:00",
"PRIORITY_ID": 1,
"TASK_NAME": "project 1 task 1",
"DESCRIPTION": "adsf"
},
{
"$id": "6",
"pb_Projects": {
"$ref": "1"
},
"TASK_ID": 2,
"PROJECT_ID": 1,
"USER_ID": 2,
"DUE_DATE": "2012-11-19T00:00:00",
"PRIORITY_ID": 1,
"TASK_NAME": "project 1 task 2 user 2",
"DESCRIPTION": "asd"
}
],
"PROJECT_ID": 1,
"USER_ID": 1,
"NAME": "Project1",
"DESCRIPTION": "project 1 description",
"BUDGET": 1000,
"LOCATION": "USA",
"START_DATE": "2012-11-18T00:00:00",
"PRIORITY_ID": 1,
"PROJ_SCALE": null,
"NOTES": null
},
{
"$ref": "3"
}
]
控制器如下：
public IEnumerable<pb_Projects> Getpb_Projects()
{
return db.pb_Projects.AsEnumerable();
}
我对这个json结果的期望是与任何其他相对FK等项目（对象）的列表。而在这里我得到一个大对象，另一个ref作为第二个对象。我做错了什么，我会期待这样的事情（不要担心它只是测试数据所以没有真正的密码：P）......
[
{
"$id": "1",
"UserId": 1,
"CreateDate": "2012-11-18T21:46:56.78",
"ConfirmationToken": null,
"IsConfirmed": true,
"LastPasswordFailureDate": null,
"PasswordFailuresSinceLastSuccess": 0,
"Password": "AIGvGbJIedgTyY+m08DCVhZbVnRTWzW6kvl1JMOqsFqOCSjnJTBlGUGmVveAYIONJw==",
"PasswordChangedDate": "2012-11-18T21:46:56.78",
"PasswordSalt": "",
"PasswordVerificationToken": null,
"PasswordVerificationTokenExpirationDate": null
},
{
"$id": "2",
"UserId": 2,
"CreateDate": "2012-11-18T21:48:05.067",
"ConfirmationToken": null,
"IsConfirmed": true,
"LastPasswordFailureDate": null,
"PasswordFailuresSinceLastSuccess": 0,
"Password": "ACeoUpOVNEvgumvmSkFziRkNQzTlZC8+KAy32egXQseKLmhmJGX/VDXRXylkBUph3Q==",
"PasswordChangedDate": "2012-11-18T21:48:05.067",
"PasswordSalt": "",
"PasswordVerificationToken": null,
"PasswordVerificationTokenExpirationDate": null
},
{
"$id": "3",
"UserId": 3,
"CreateDate": "2012-11-19T00:35:49.163",
"ConfirmationToken": null,
"IsConfirmed": true,
"LastPasswordFailureDate": null,
"PasswordFailuresSinceLastSuccess": 0,
"Password": "AF7W+1FNLcaA2qJ3nmrB7S9mkJmJGZCpAZYbyH5+iXryq1epr8i67ddgSbvFQF1bQw==",
"PasswordChangedDate": "2012-11-19T00:35:49.163",
"PasswordSalt": "",
"PasswordVerificationToken": null,
"PasswordVerificationTokenExpirationDate": null
},
{
"$id": "4",
"UserId": 4,
"CreateDate": "2012-11-19T00:39:00.667",
"ConfirmationToken": null,
"IsConfirmed": true,
"LastPasswordFailureDate": null,
"PasswordFailuresSinceLastSuccess": 0,
"Password": "ABPdfSj8jZAWqhHMDuTVQuL3AiEmiplSujA/GNjQoGoMQm0zhNwAAOaInbqrXFrM0g==",
"PasswordChangedDate": "2012-11-19T00:39:00.667",
"PasswordSalt": "",
"PasswordVerificationToken": null,
"PasswordVerificationTokenExpirationDate": null
}
这是原始未格式化的JSON
[{"$id":"1","pb_Priority":{"$id":"2","pb_Projects":[{"$ref":"1"},{"$id":"3","pb_Priority":{"$ref":"2"},"pb_Tasks":[],"PROJECT_ID":2,"USER_ID":2,"NAME":"test2","DESCRIPTION":"test2","BUDGET":1.0,"LOCATION":"test","START_DATE":"2012-11-18T00:00:00","PRIORITY_ID":1,"PROJ_SCALE":null,"NOTES":null}],"PRIORITY_ID":1,"PRIORITY_LEVEL":1},"pb_Tasks":[{"$id":"4","pb_Projects":{"$ref":"1"},"TASK_ID":1,"PROJECT_ID":1,"USER_ID":1,"DUE_DATE":"2012-11-19T00:00:00","PRIORITY_ID":1,"TASK_NAME":"asdf","DESCRIPTION":"adsf"},{"$id":"5","pb_Projects":{"$ref":"1"},"TASK_ID":2,"PROJECT_ID":1,"USER_ID":2,"DUE_DATE":"2012-11-19T00:00:00","PRIORITY_ID":1,"TASK_NAME":"sdf","DESCRIPTION":"asd"},{"$id":"6","pb_Projects":{"$ref":"1"},"TASK_ID":3,"PROJECT_ID":1,"USER_ID":2,"DUE_DATE":"2012-11-19T00:00:00","PRIORITY_ID":2,"TASK_NAME":"dsf","DESCRIPTION":"asdf"}],"PROJECT_ID":1,"USER_ID":1,"NAME":"test","DESCRIPTION":"test","BUDGET":null,"LOCATION":"test","START_DATE":"2012-11-18T00:00:00","PRIORITY_ID":1,"PROJ_SCALE":null,"NOTES":null},{"$ref":"3"}]
答案 0 :(得分：3)
如果您使用EF，默认情况下，它将延迟加载导航属性中的所有数据。当序列化程序序列化模型时，它将访问模型上的每个属性，EF将加载所有嵌套数据。
作为最佳做法，您不应将您的数据库模型公开为web api模型。您最好创建另一个DTO模型，您可以准确控制将返回给客户端的内容以及您希望从客户端接收的内容。
或者您可以通过修改器隐藏这些导航属性（将其标记为内部）或使用[IgnoreDataMember]属性来快速解决此问题。它告诉序列化程序在序列化和去序列化时不要访问它们。