angularjs - 将 IEnumerable 从 web api Controller 发送到 angular js

Question

我正在尝试将 IEnumerable 从 Web API Controller 发送到 AngularJs Controller 。我使用的代码是

网络接口(interface):

readonly InventoryEntities _db = new InventoryEntities();

public IEnumerable<FDVOEligibilityRequest> Get()
{
   return _db.FDVOEligibilityRequests.AsEnumerable();
}

AngularJS:

//get all customer information
$http.get("/api/Customer/").success(function (data) {
        $scope.requests = data;
        $scope.loading = false;
    })
    .error(function () {
        $scope.error = "An Error has occured while loading posts!";
        $scope.loading = false;
    });

这工作正常，但现在我正在使用 linq 来包含相关表，但它不起作用。 angularJs 代码是一样的。我做错了什么？

readonly InventoryEntities _db = new InventoryEntities();

public IEnumerable<FDVOEligibilityRequest> Get()
{
    return _db.FDVOEligibilityRequests
        .Include("FDVOEligibilityRequestMandatoryField")
        .Include("FDVOEligibilityRequestDCCField").AsEnumerable();
}

我确实在 Controller 中获得了我想要的数据，但是当我尝试将它发送回 Angular 时，我得到了 500(内部服务器错误)angular.js:10722

这就是 FDVOEligibilityRequest 在新的 Web Api Controller 中的样子

public partial class FDVOEligibilityRequest
{
    public int Id { get; set; }
    public string TestName { get; set; }
    public string GroupName { get; set; }
    public int MandatoryFieldsID { get; set; }
    public int DCCFieldsID { get; set; }
    public virtual FDVOEligibilityRequestMandatoryField FDVOEligibilityRequestMandatoryField { get; set; }
    public virtual FDVOEligibilityRequestDCCField FDVOEligibilityRequestDCCField { get; set; }
}

Answer 1

如果它是 500 并且发生在您成功地从您的操作返回之后，那么它可能是序列化期间的异常。

我建议检查 FDVOEligibilityRequest 和 FDVOEligibilityRequestMandatoryField/FDVOEligibilityRequestDCCField 之间没有循环引用。

或者尝试使用来自 here 的代码对其进行诊断:

string Serialize<T>(MediaTypeFormatter formatter, T value)
{
    // Create a dummy HTTP Content.
    Stream stream = new MemoryStream();
    var content = new StreamContent(stream);
    /// Serialize the object.
    formatter.WriteToStreamAsync(typeof(T), value, stream, content, null).Wait();
    // Read the serialized string.
    stream.Position = 0;
    return content.ReadAsStringAsync().Result;
}

try {
    var val = _db.FDVOEligibilityRequests
        .Include("FDVOEligibilityRequestMandatoryField")
        .Include("FDVOEligibilityRequestDCCField").AsEnumerable();
    var str = Serialize(new JsonMediaTypeFormatter(), val);
}
catch (Exception x) 
{ // break point here
}

ps:common suggestion在这种情况下是使用 DTO 而不是 EF 对象，类似 Automapper .