Crystal Report 错误：数据源对象无效

Question

我正在尝试使用水晶报告打印学生证，但我得到的只是弹出此错误The data source object is invalid.

如果我犯了任何错误，请帮我检查此代码...

这是模型

public class CardModel
{
        // Properties
        public string Department { get; set; }

        public string ExpiryDate { get; set; }

        public string FirstName { get; set; }

        public Sex Gender { get; set; }

        public Guid Id { get; set; }

        public string MiddleName { get; set; }

        public string RegistrationNo { get; set; }

        public byte[] SecuritySign { get; set; }

        public byte[] StudentPhoto { get; set; }
        public string Surname { get; set; }
}

public static class CardModelExtention
{
    public static CardModel ToCardModel(this Student identity)
    {
        return new CardModel
        {
            Id = identity.Id,
            FirstName = identity.FirstName,
            MiddleName = identity.MiddleName,
            Surname = identity.Surname,
            StudentPhoto = identity.Photo.RawPhoto,
            SecuritySign = identity.SecuritySignature.RawSignature,
            Gender = identity.Sex,
            ExpiryDate = identity.ExpiryDate,
            Department = identity.Department.DepartmentName,
            RegistrationNo = identity.RegistrationNo
        };
    }
}

这是用于从数据库中提取信息的服务

public class StudentService : IStudentService
{
    ERMUoW _ow;
    public StudentService()
    {
        _ow = new ERMUoW();
    }

    public CardModel GetStudentById(Guid id)
    {
        CardModel obj3 = new CardModel();

            Student student  = _ow.Students.GetAllIncluding(new Expression<Func<Student, object>>[] { st => st.Photo, st => st.Signature, st => st.SecuritySignature, st => st.Department }).Where(x => x.Id == id).SingleOrDefault();

            var cardInfo = student.ToCardModel();

        return cardInfo;
    }
}

public interface IStudentService
{
    CardModel GetStudentById(Guid id);
}

就是这样，这里的一切都工作正常，并且很好地获取数据，但是当我将它发送到我的控制器中生成身份证的方法时，我收到了错误消息

这是使用水晶报告生成卡片的代码

public ActionResult PrintCard(Guid id)
    {
        var student = _studentCardService.GetStudentById(id);

        ReportDocument read = new ReportDocument();

        read.Load(Server.MapPath("~/Reports/rpt_StudentCard.rpt"));

        read.SetDataSource(student);
        Response.Buffer = false;
        Response.ClearContent();
        Response.ClearHeaders();

        try
        {
            Stream stream = read.ExportToStream(CrystalDecisions.Shared.ExportFormatType.PortableDocFormat);
            stream.Seek(0, SeekOrigin.Begin);
            return File(stream, "application/pdf", "StudentIdentityCard.pdf");
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

非常感谢您的帮助，谢谢...

Answer 1

数据源必须是元素列表...而不是单个元素。