我有
public class Lead
{
public string LeadFirstName { get; set; }
public List<Document> Documents { get; set; }
}
public class Document
{
public int DocumentId { get; set; }
public string DocumentPath { get; set; }
}
当我在做以下时
Lead lead = new Lead();
lead.LeadFirstName = "Test";
lead.Documents.Add(new Document{ DocumentId = 1, DocumentPath = @"C:\test\abc.doc"});
我收到Null Reference异常。 - 为什么?
答案 0 :(得分:3)
您没有实例化您的文档列表。一种方法是通过构造函数:
public class Lead
{
public Lead()
{
Documents = new List<Document>();
}
public string LeadFirstName { get; set; }
public List<Document> Documents { get; private set; }
}
答案 1 :(得分:1)
您必须初始化集合:
Lead lead = new Lead();
lead.LeadFirstName = "Test";
lead.Documents = new List<Document>(); <<-----
lead.Documents.Add(new Document{ DocumentId = 1, DocumentPath = @"C:\test\abc.doc"});