Question

how can i compare the items in a string[] array against a generic list that contains objects using LINQ?

this generic list contains objects called picInfo. picinfo class looks like this:

[ProtoContract]
public class PicInfo
{
[ProtoMember(1)]
public string fileName { get; set; }
[ProtoMember(2)]
public string completeFileName { get; set; }
[ProtoMember(3)]
public string filePath { get; set; }
[ProtoMember(4)]
public byte[] hashValue { get; set; }

public PicInfo() { } 
}

the string[] array contains filepaths of pictures. im trying to check if the generic list already contains the path of this particular picture.

the generic list of the pictures looks like this:

List<PicInfo> pi = new List<PicInfo>();

if the generic list already has that picture, i’d like to remove the item from the string[] array.

i can do this using the foreach loop and compare the items 1 by 1. but how can i do this using linq?

thanks in advance!

Answer 1

You could just determine the duplicates and then remove them:

var duplicates = pi.Where(p => picArray.Contains(p.filePath);
foreach(string fileName in duplicates)
{
   //do something
}

But a cleaner approach and more readable would be using Except() and creating a new array, although this is a little more overhead for the array creation:

picArray = picArray.Except(pi.Select(p=> p.filePath)).ToArray();