本文介绍了转换IEnumerable&lt; T&gt;到EntitySet&lt; T&gt;的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧! 问题描述 29岁程序员,3月因学历无情被辞! 如何转换IEnumerable< T>到EntitySet< T>? var questions =来自e.Element中的q("问题")。元素("问题") 选择新问题 { Text = q.Attribute (" title")。Value, Point = Convert.ToDecimal(q.Attribute(" point"。)。), Choices = from c在q.Elements("Choices")中。元素("Choice") 选择新的选择 { Text = c.Attribute(" title")。Value, Correct = Convert.ToBoolean(c.Attribute(" isCorrect")。Value) } ; 以粗体显示的行抛出错误: 错误1无法隐式将类型'System.Collections.Generic.IEnumerable< DomainObjects.Choice>'转换为'System.Data.Linq.EntityS等人LT; DomainObjects.Choice>"。存在显式转换(您是否缺少演员表?)C:\Projects \ExamDLINQ \ExamDLINQSolution\ExamDLINQConsole\Program.cs 29 43 ExamDLINQConsole 解决方案 我认为没有任何内置方法可以实现这一目标。推测问题是一个LINQ to SQL实体,你想在之后插入到表中? 一种解决方案是编写自己的ToEntitySet扩展方法: public static EntitySet< T> ToEntitySet< T> (此IEnumerable< T>源)其中T:class { var es = new EntitySet< T> (); es.AddRange(source); return es; } 然后你可以编写你的查询如下: var questions = from e inElement(" Questions" ;)元素("问题") 结果 Hi, How can I convert IEnumerable<T> to EntitySet<T>?  var questions = from q in e.Element("Questions").Elements("Question")                            select new Question                            {                                Text = q.Attribute("title").Value,                                Point = Convert.ToDecimal(q.Attribute("point").Value),                                Choices = from c in q.Elements("Choices").Elements("Choice")                                          select new Choice                                          {                                                                                        Text = c.Attribute("title").Value,                                              Correct = Convert.ToBoolean(c.Attribute("isCorrect").Value)                                          }                                                                       };The lines in bold throw the error: Error    1    Cannot implicitly convert type 'System.Collections.Generic.IEnumerable<DomainObjects.Choice>' to 'System.Data.Linq.EntitySet<DomainObjects.Choice>'. An explicit conversion exists (are you missing a cast?)    C:\Projects\ExamDLINQ\ExamDLINQSolution\ExamDLINQConsole\Program.cs    29    43    ExamDLINQConsole                            解决方案 I don't think there's any built-in way to achieve this. Presumably Question is a LINQ to SQL entity which you want to insert into the table afterward?One solution would be to write your own ToEntitySet extension method:    public static EntitySet<T> ToEntitySet<T> (this IEnumerable<T> source) where T : class    {        var es = new EntitySet<T> ();        es.AddRange (source);        return es;    }Then you could write your query as follows:var questions = from q in e.Element("Questions").Elements("Question") 这篇关于转换IEnumerable&lt; T&gt;到EntitySet&lt; T&gt;的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持! 上岸,阿里云!
07-23 02:59
查看更多