I want to delete attachment and listitem but using this code it deletes all the listitems

Question

private void DeleteFromSharePointList(HyperLink hp)
{
         SPWeb web = SPContext.Current.Web;
         web.AllowUnsafeUpdates = false;

         SPList myList = web.Lists["Document cv"];

         SPListItemCollection lstCol = myList.Items;

         foreach (SPListItem lstItem in lstCol)
         {
             if (lstItem == null) return;

             var fileNames = lstItem.Attachments.Cast<string>().ToList();

             for (int i = 0; i < fileNames.Count; i++)
             {
                 var fileName = fileNames[i];
                 if (lstItem.Attachments.UrlPrefix + fileName == hp.NavigateUrl)
                 {
                     lstItem.Attachments.Delete(fileName);  
                 }    
             }

             lstItem.Update();

             SPListItem itemToDelete = myList.GetItemById(lstItem.ID);
             itemToDelete.Delete();
            }              
        }
    }

Answer 1

There is no condition around the code to delete the list item, and it's inside a foreach loop, so of course it will delete all of the list items.

I think you want something like:

     foreach (SPListItem lstItem in lstCol)
     {
         bool deleteThisItem = false;
         if (lstItem == null) return;

         var fileNames = lstItem.Attachments.Cast<string>().ToList();

         for (int i = 0; i < fileNames.Count; i++)
         {
             var fileName = fileNames[i];
             if (lstItem.Attachments.UrlPrefix + fileName == hp.NavigateUrl)
             {
                 lstItem.Attachments.Delete(fileName);
                 deleteThisItem = true;
             }

          }
          if(deleteThisItem)
          {
            lstItem.Update();
            SPListItem itemToDelete = myList.GetItemById(lstItem.ID);
            itemToDelete.Delete();
          }
     }

I've not dealt with attachments so I don't know if what you are trying to do (delete attachments with a certain name, and then delete the item that had that attachment) makes sense or if you need the lstItem.Update() before the itemToDelete.Delete().