c# - IAsyncResult 输出字符串始终为空

Question

我的字符串消息始终为空，我的 Result AsyncState 也始终为空。有人看到错误了吗？

private void create_Incident(string computer_idn, string swidn_choice,
                             string swName_choice, string CI_Number,
                             string windows_user)
{
    string msg_id = "" + computer_idn + "_" + swidn_choice + "";
    string username = "BISS";

    server3.ILTISAPI api = new server3.ILTISAPI();
    api.BeginInsertIncident(username, "", msg_id, "", "", "2857",
        "BISS - Software Deployment", "", "", "NOT DETERMINED", "", "", "", "",
        "", "", "5 - BAU", "3 - BAU", "", "Interface", "", "", "", "", "", "", 
        delegate(IAsyncResult r) { InsertIncidentCallback(api, r); }, null);
}

private void InsertIncidentCallback(server3.ILTISAPI api,
                                    IAsyncResult result)
{
    // do something and then:
    string message;
    api.EndInsertIncident(result, out message);
}

返回值：<0 错误（更多信息可以在 msg 参数中找到）。=0 好的。=1 好的。详细方法：

public IAsyncResult BeginInsertIncident(string userName, string password, 
                                        string MsgId, string ThirdPartyRef, 
                                        string Type, string EmployeeId, 
                                        string ShortDescription, string Details,
                                        string Category, string Service, 
                                        string  OwnerGrp, string OwnerRep, 
                                        string SecondLevelGrp, 
                                        string SecondLevelRep, 
                                        string ThirdLevelGrp, 
                                        string ThirdLevelRep, string Impact, 
                                        string Urgency, string Priority, 
                                        string Source, string Status, 
                                        string State, string Solution, 
                                        string ResolvedDate, string Cause, 
                                        string Approved, AsyncCallback callback, 
                                        object asyncState);

public int EndInsertIncident(IAsyncResult asyncResult, out string msg);

我想检查味精，如果有错误或正常。

Answer 1

异步状态是您传入的备用状态object。您正在传入null（作为最终参数）；因此AsyncState永远是null。

如果您不想要null，请将其他内容作为最终参数传入。