odata - SingleResult 无法在 Web API 中按键查询时序列化

Question

尝试使用主键 CourseID 针对 odata web.api 使用以下命令查找单个记录:

var editedcourse = container.Courses.Where(c => c.CourseID == ID).SingleOrDefault();

这是错误:

    <m:innererror>
    <m:message>The 'ObjectContent`1' type failed to serialize the response body for content type 'application/atom+xml; charset=utf-8'.</m:message>
    <m:type>System.InvalidOperationException</m:type>
    <m:stacktrace></m:stacktrace>
    <m:internalexception>
      <m:message>'SingleResult`1' cannot be serialized using the ODataMediaTypeFormatter.</m:message>
      <m:type>System.Runtime.Serialization.SerializationException</m:type>

Answer 1

默认情况下 web.api Controller 方法不可查询，因此客户端失败。添加注释以修复:[Queryable(AllowedOrderByProperties = "Id")]