REST是否可以为空？

Question

我打了砖墙.我的REST实现不接受Nullable值.

    [OperationContract]
    [WebInvoke(ResponseFormat = WebMessageFormat.Json, UriTemplate = "/Transactions?AccNo={AccNo}&CostCentreNo={CostCentreNo}&TransactionType={TransactionType}&Outstanding={Outstanding}&CheckStartDate={CheckStartDate}&CheckEndDate={CheckEndDate}")]
    List<Transactions> GetTransactions(Int32 AccNo, Int32 CostCentreNo, Int32 TransactionType, Boolean Outstanding, DateTime? CheckStartDate, DateTime? CheckEndDate);

而我原来的SOAP实现确实如此.那么有办法解决这个问题吗？或者我是否必须重新编写代码？

我仍然不明白为什么日期时间必须可以为空以便设置为null.

Answer 1

UriTemplate查询值的变量必须具有可由QueryStringConverter转换的类型.可空类型不是.

你可以包装参数并通过POST传递它;

[DataContract(Name = "Details", Namespace = "")]
public class Details
{
    [DataMember]
    public Int32 AccNo;
    [DataMember]
    public Int32 CostCentreNo;
    [DataMember]
    public Int32 TransactionType;
    [DataMember]
    public Boolean Outstanding;
    [DataMember]
    public DateTime? CheckStartDate;
    [DataMember]
    public DateTime? CheckEndDate;

    public Details()
    {}
}

[OperationContract]
[WebInvoke(Method = "POST", UriTemplate = "/Transactions",
     RequestFormat = WebMessageFormat.Json,
     ResponseFormat = WebMessageFormat.Json,
     BodyStyle = WebMessageBodyStyle.Bare)]
List<Transactions> GetTransactions(Details details);

通常,您可以将日期作为字符串而不是DateTime传递,然后在接收端的字符串上使用DateTime.Parse().