实体类序列化为 json答案

【问题标题】：Entity class serialize to json实体类序列化为 json
【发布时间】：2012-05-30 19:46:30
【问题描述】：

       try
        {
            using (EXAMINATIONEntities entity = new EXAMINATIONEntities())
            {
                JavaScriptSerializer serializer = new JavaScriptSerializer();
                var exams = entity.TBL_EXAMS.Where(x => x.USERID == userId);                    
                return serializer.Serialize(exams);
            }
        }
        catch (Exception ex)
        {
            return "-1";
            throw ex;
        }

此代码运行良好。但是返回一个像这样的json字符串；

[{"EXAM_ID":1,"EXAM_TEXT":"sdf","EXAM_ORDER":1,"SITUATION":true,"USERID":100,"DBDATETIME":null,"TBL_QUESTIONS":[], "EntityState":2,"EntityKey":{"EntitySetName":"TBL_EXAMS","EntityContainerName":"EXAMINATIONEntities","EntityKeyValues":

我只想序列化表字段： "EXAM_ID":1,"EXAM_TEXT":"sdf","EXAM_ORDER":1,"SITUATION":true,"USERID":100, "DBDATETIME":null

但它会序列化所有实体类字段和属性。如何序列化我想要序列化的实体类字段？

【问题讨论】：

标签： c# json linq entity-framework serialization

【解决方案1】：

您只能将您想要的属性投影到匿名类型：

JavaScriptSerializer serializer = new JavaScriptSerializer();
var exams = entity.TBL_EXAMS.Where(x => x.USERID == userId)
           .Select(exam => new {
                      exam.EXAM_ID, exam.EXAM_TEXT, exam.EXAM_ORDER /* etc */
                   });                    
return serializer.Serialize(exams);

【讨论】：