WebApi JSON Output

Question

所以我在MVC4中创建了一个WebApi项目，但在理解JSON输出时遇到了问题。我不完全确定这是JSON的预期输出，还是我做了一些错误的事情。

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，每个项目都可以有一个优先级。

实体http://img705.imageshack.us/img705/9294/stackoverflowentities.png

现在，我收到的输出很奇怪，也不是很直观。我不确定这是否是预期的JSON(因为我对它是全新的)。当我运行网站来检索项目的JSON输出时，我得到了以下结果。

[
{
"$id": "1",
"pb_Priority": {
"$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();
}

我希望从这个json结果中得到一个项目(对象)列表，其中包含任何其他相关的FK等等。而在这里，我得到了一个大物体，另一个裁判作为第二个物体。如果我做错了什么，我会期待这样的事情(别担心，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
}

]

以下是未格式化的原始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"}]

Answer 1

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。

作为一种最佳实践，您不应该将DB模型公开为webapi模型。您最好创建另一个DTO模型，您可以准确地控制将返回给客户端的内容以及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(将它们标记为内部)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反序列化时不要访问它们。