c# - SAP 企业服务工作区

Question

我正尝试在 .Net/C# 中使用其中一些服务。一些服务可以很容易地使用，但对于其他服务我有一个误导性错误。

这部分代码:

        input.AcademicProgramOfStudySelectionByName = new AcademicProgramOfStudyByNameQueryMessage_syncAcademicProgramOfStudySelectionByName();
        input.AcademicProgramOfStudySelectionByName.AcademicProgramOfStudyName.languageCode = "DE";

我在第二行收到错误“对象引用未设置到对象实例”。 但我已经在第一行创建了对象!

相同的代码在其他一些服务中也有效!

Answer 1

您创建了对象 input.AcademicProgramOfStudySelectionByName，但您没有创建其成员 input.AcademicProgramOfStudySelectionByName.AcademicProgramOfStudyName。看起来，类 AcademicProgramOfStudyByNameQueryMessage_syncAcademicProgramOfStudySelectionByName 的构造函数不会填充其成员 AcademicProgramOfStudyName。因此，当您尝试为 AcademicProgramOfStudyName 的成员赋值并且该实例为 NULL 时，您会得到一个异常。

示例代码:

    AcademicProgramOfStudyByNameQueryResponse_InClient client = 
        new AcademicProgramOfStudyByNameQueryResponse_InClient(); 


    client.ClientCredentials.UserName.UserName = "XX";
    client.ClientCredentials.UserName.Password = "YY";

    AcademicProgramOfStudyByNameQueryMessage_sync input =
        new AcademicProgramOfStudyByNameQueryMessage_sync();


    input.AcademicProgramOfStudySelectionByName = new AcademicProgramOfStudyByNameQueryMessage_syncAcademicProgramOfStudySelectionByName();

    // this is the member that currently is still NULL and has to be created:
    input.AcademicProgramOfStudySelectionByName.AcademicProgramOfStudyName = new <insert whatever class is needed here>

    // now this should work without throwing an exception
   input.AcademicProgramOfStudySelectionByName.AcademicProgramOfStudyName.languageCode = "DE";

    AcademicProgramOfStudyByNameResponseMessage_sync output = 
        new AcademicProgramOfStudyByNameResponseMessage_sync(); 

    output = client.AcademicProgramOfStudyByNameQueryResponse_In(input);