如何在Linq中循环遍历.select语句中的所有元素 [英] How can I loop Through all the elements in .select statement in Linq

问题描述

我正在尝试打印书名，作者名"(某些书有一位以上的作者) 在Linq代码下面仅打印第一作者.如何打印与一本书相关的所有作者?

I am trying to Print "Title of the Book , AuthorNames " (Some Books have more than one author) Below Linq code is printing only first author. How can I print all the authors associated with a book?

 List<string> books = docs.Descendants(name)

   .Select(x => new {
       Title = (string)x.Element(ns+"TITLE"),
           Author = x.Element(ns+"INTEL_AUTH")
        })
.Select(x => new {
           Title = x.Title,
           FirstName = (string) x.Author.Element(ns+"FNAME"),
           MiddleInitial = (string) x.Author.Element(ns+"MNAME"),
           LastName = (string) x.Author.Element(ns+"LNAME"),
        })
.Select(x => string.Format("{0}: {1} {2} {3}",
                           x.Title,
                           x.FirstName, x.MiddleInitial, x.LastName))
.ToList();

for (int i = 0; i < books.Count; i++)
{       
   Response.Write("--" + books[i] + "<BR />" );      
}

XML 这是xml代码. 测试1 约翰 美国能源部 约翰 斯基特

XML Here is the xml code. TEST 1 JOHN DOE JOHN SKEET

 <INTEL_AUTH ID="10">
 <FNAME>JO</FNAME>
 <MNAME></MNAME>
 <LNAME>JO</LNAME>
 <INTEL_AUTH>
 </INTEL>

  <INTEL>
  <TILE> LEARNING LINQ</TITLE>
  <INTEL_AUTH ID="2">
  <FNAME> SHELLY</FNAME>
  <MNAME></MNAME>
  <LNAME>SHELLY</LNAME>
  <INTEL_AUTH iD="3">
  <FNAME>CHRIS</FNAME>
  <MNAME></MNAME>
  <LNAME>MADISON</LNAME>
  </INTEL_AUTH>


  </INTEL>
  </RECORD>
  </XML>

我希望显示输出，例如:(标题):所有写过该书的作者

I WANT THE OUTPUT TO BE DISPLAYED LIKE : (TITLE) : ALL AUTHORS WHO WROTE THAT BOOK

测试1:JOHN DOE，JOHN SKEET，JO JO 学习LINQ:SHELLY SHELLY，克里斯·麦迪森

TEST 1 : JOHN DOE , JOHN SKEET , JO JO LEARNING LINQ : SHELLY SHELLY , CHRIS MADISON

推荐答案

目前尚不清楚您是要一个具有多个作者的结果，还是要每个作者一个结果，还是希望在List<string>.我怀疑这可以满足您的需求:

It's not clear whether you want a single result with multiple authors, or a single result per author, or how you'd expect this to be represented in a List<string>. I suspect this will do what you need though:

var query = docs.Descendants(name)
    // First get the relevant elements out of the main book element
    .Select(x => new {
        Title = (string) x.Element(ns + "TITLE"),
        Authors = x.Elements(ns + "INTEL_AUTH")
     })
    // Now transform them from LINQ to XML into plain objects
    .Select(x => new {
        Title = x.Title,
        Authors = x.Authors.Select(a => new {
            FirstName = (string) a.Element(ns + "FNAME"),
            MiddleInitial = (string) a.Element(ns + "MNAME"),
            LastName = (string) a.Element(ns + "LNAME")
        })
     });

 foreach (var book in query)
 {
     Console.WriteLine("{0}:", book.Title);
     foreach (var author in book.Authors)
     {
         Console.WriteLine("  {0} {1} {2}",
                           author.FirstName, author.MiddleInitial,
                           author.LastName);
     }
 }

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