dnn linqtosql对象引用未设置为对象异常的实例

Question

我有这样的代码试图将一些信息保存到数据库但是我的datacontext无法创建。它给出了一个例外“对象引用没有设置为对象的实例。”当我调试时，它跳转到“DataContext1 db = new DataContext1（）;” line to catch block并给出异常。这有什么解决方案吗？

public class AuthorPaperDetails
{
    public void SaveAuthorPaperDetails(string pTitle, string confMakerId, 
                                                string additionalPaperTitle,string mainAuthor, 
                                                int regFeeForFirstAuthor,int regFeeForAdditionalPaper, int RegFeeForCoAuthors)
    {

        try
        {
            DataContext1 db = new DataContext1();
            AuthorPaperDetail authorPaperDetail = new AuthorPaperDetail();

            authorPaperDetail.paper_title = pTitle;
            authorPaperDetail.conference_maker_id = confMakerId;
            authorPaperDetail.additional_paper_title = additionalPaperTitle;
            authorPaperDetail.areYouMainAuthor = mainAuthor;
            authorPaperDetail.feeForFirstAuthorPaper = regFeeForFirstAuthor;
            authorPaperDetail.feeForAdditionalPaper = regFeeForAdditionalPaper;
            authorPaperDetail.feeForParticipCoAuthors = RegFeeForCoAuthors;

            db.AuthorPaperDetails.InsertOnSubmit(authorPaperDetail);
            db.SubmitChanges();
        }
        catch (Exception)
        {
        }
    }
}

Answer 1

创建dbml时是不是保存了连接信息，还是需要将连接信息传递给DataContext，如下所示：

TestDataContext dc = new TestDataContext("ConnectionString1");