在 foreach c# 中更新 foreach

Question

The code snippet shown will compare each element in the first list with one element in the second one. But when the inner foreach finishes, the upper foreach re-enters and the image throws the same guid in both lists. How can I get it to not do this?

   var listDetail = await _repo.GalleryDetail.GetAllAsync(a => a.GalleryId == request.Id);

        request.GalleryDetails.ToList().ForEach(a =>
        {
            if (a.File == null) 
            {
                foreach (var item in listDetail)
                {
                    a.Image = item.Image;
                }
            }
            else
            {
                foreach (var item in listDetail)
                {
                    if (item.Image != null && item.Image != "True")
                        item.Image = a.File.DeleteFtp(url: item.Image.Substring(7), 
          cdn).ToString();
                }

                a.Image = a.File.UploadFtp("GalleryDetail", cdn);
            }
        });

Answer 1

This overwrites a.Image for every item in listDetail , therefore you get the last Image :

foreach (var item in listDetail)
{
    a.Image = item.Image;
}

As you have an Id property, I suggest using it for synchronization:

foreach (var item in listDetail)
{
    if (item.Id == a.Id)
    {
        a.Image = item.Image;
        break;
    }
}

I added a break; so you break out of the loop as soon as you found a match.