Combine LINQ queries

Question

I\'m in the process of making a small query thing for a set of results of files.

public class f_results
    {
        public String name { get; set; }
               


        

Answer 1

You could generate your filters beforehand, then apply them all at once - you would only have to iterate your initial enumeration once, something like this (shortened):

IEnumerable foundfiles = new List();
var filters = new List>();

if (fsize.Text.Trim() != "")
{
    long sz = long.Parse(fsize.Text);
    filters.Add(x => x.size >= sz);
}

if (adate.Text.Trim() != "")
{
    DateTime test = DateTime.Parse(adate.Text);
    filters.Add(x => x.adate >= test);
}

foreach (var filter in filters)
{
    var filterToApply = filter;
    foundfiles = foundfiles.Where(filterToApply);
}
finalResults = new BindingList(foundfiles);

More importantly don't call ToList() until you have processed all filters, otherwise you keep iterating through your full result list over and over.