Cannot implicitly convert type system.colllections.generic

Question

I'm getting the following error:

Cannot implicitly convert type 'System.Collections.Generic.List>' to 'System.Collections.Generic.List

The code I have is:

class Check
{
      public string Text { get; set; }

      public  List<Check> getxml()
      {
          XDocument xdoc = XDocument.Load(@"D:\Web Utf-8 Converter\Categories.xml");

          var list = (from p in xdoc.Descendants("Categories")
                      select p.Elements("name"));

          var listing = list.ToList();

          return listing;
      }
}

This seems to me like a conversion error. But I'm not sure how to convert. Kindly assist.

Thank you.

It is simply because it is two different classes. If your Check class is supposed to hold the info from the xml then you have to store it in a new Check class then return that list. Currently you are trying to return a list. — deathismyfriend, Oct 01 '14 at 05:48

score 2 · Answer 1 · answered Oct 01 '14 at 05:56

According to your edits, it should be something like this:

return xdoc
    .Descendants("Categories")
    .SelectMany(_ => _.Elements("name"))
    .Select(_ => new Check(_.Value))
    .ToList();

Note, that getxml shouldn't be an instance method of Check class. It should be at least static factory method.

Koenyn · Accepted Answer · 2014-10-01T06:37:57.580

1

the select statement is returning a System.Xml.Linq.XElement. The return type of your method is List. These are not the same.

what you can do is:

 var list = (from p in xdoc.Descendants("Categories")
     select new Check { Text = p.Elements("name").Value});

However I think your class Check should not read the xml and store the results of each element.

You should rather have a class "XmlParser" which has the GetXml Method and a class "XmlValue" which holds the information. i.e.

public class XmlValue
{
    public System.Xml.Linq.XElement Element { get; set; }
    public string Text
    {
        get
        {
            if(Element == null) return null;
            return Element.Value;
        }
    }
}

public class XmlParser
{
    public List<XmlValue> GetXml()
    {
        XDocument xdoc = XDocument.Load(@"D:\Web Utf-8 Converter\Categories.xml");

        return xdoc
            .Descendants("Categories")
            .SelectMany(p => p.Elements("name"))
            .Select(p => new XmlValue { Element = p });
            .ToList();
    }
}

void Main()
{
    XmlParser parser = new XmlParser();
    var list = parser.GetXml();
    foreach(var el in list)
        Console.WriteLine(el.Text);
}

edited Oct 01 '14 at 06:37

answered Oct 01 '14 at 05:54

Koenyn

694
4
16

'Cannot implicitly convert type 'System.Collections.Generic.IEnumerable' to 'System.Xml.Linq.XElement'. An explicit conversion exists (are you missing a cast?)' – user726720 Oct 01 '14 at 06:08
getting the above error at 'Element = p.Elements("name")' – user726720 Oct 01 '14 at 06:08
This works thanks, but it returns the complete element. How can I get it's attribute – user726720 Oct 01 '14 at 07:26
This is what is being returned: , I need just the text part – user726720 Oct 01 '14 at 07:27
I accept your answer I'll raise another question for this. Thanks – user726720 Oct 01 '14 at 08:00

score 0 · Answer 3 · answered Oct 01 '14 at 05:55

You are returning a list coming from

var list = (from p in xdoc.Descendants("Categories")
                  select p.Elements("name"));

But the return type is List. A 'System.Xml.Linq.XElement' is not a 'Check', you must somehow provide the conversion. Maybe write a constructor to Check-class accepting System.Xml.Linq.XElement and then instead of returning listing, you can

return listing.Select(x => new Check(x)).ToList();

Cannot implicitly convert type system.colllections.generic

3 Answers3

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