Question

I am using HTML Agility to get all the images since image dont always have absolute path i am trying to do following. But line marked below in the code generates error

Cannot implicitly convert type ‘System.Uri’ to ‘System.Collections.Generic.List’

I am not sure how to fix this i tried so many option but keep on getting one or the other error

List<String> imgList = (from x in doc.DocumentNode.Descendants("img")
                      where x.Attributes["src"] != null
                      select x.Attributes["src"].Value.ToLower()).ToList<String>();

List<String> AbsoluteImageUrl = new List<String>();

foreach (String element in imgList)
{
    AbsoluteImageUrl = new Uri(baseUrl, element); //GIVES ERROR
}

Answer 1

The compiler generates an error, because the type of AbsoluteImageUrl is not compatible with the type of your Uri. If you need to add the Uri to a string list, you should obtain its underlying string (e.g. Uri.AbsolutePath). In this case, the code would look like this:

AbsoluteImageUrl.Add(new Uri(baseUrl, element).AbsolutePath);

On the other hand, if you need an Uri list instead, keep your original code and change the type of AbsoluteImageUrl:

List<Uri> AbsoluteImageUrl = new List<Uri>();

Once this is done, you should use AbsoluteImageUrl.Add in the loop to add the Uri to the list.

---

Regarding the discussion in comments about difference between Uri.ToString() and Uri.AbsolutePath, they have a different definitions per the official MSDN, so it depends on the OP’s requirements which he/she should use. The source code of Uri.ToString, on a side note, is as follows, so it is fundamentally different from AbsolutePath:

[SecurityPermission(SecurityAction.InheritanceDemand, Flags=SecurityPermissionFlag.Infrastructure)]
public override string ToString()
{
    if (this.m_Syntax == null)
    {
        if (this.m_iriParsing && this.InFact(Flags.HasUnicode))
        {
            return this.m_String;
        }
        return this.OriginalString;
    }
    this.EnsureUriInfo();
    if (this.m_Info.String == null)
    {
        if (this.Syntax.IsSimple)
        {
            this.m_Info.String = this.GetComponentsHelper(UriComponents.AbsoluteUri, (UriFormat) 0x7fff);
        }
        else
        {
            this.m_Info.String = this.GetParts(UriComponents.AbsoluteUri, UriFormat.SafeUnescaped);
        }
    }
    return this.m_Info.String;
}