Lambda problem I can not seem to figure out.

I really have no idea how to figure this out, please help.

I have this filter button that is suppose to filter a listbox based on what is filled in a textbox and a list that is used to add the names the listbox

this is my code:

public void FilterButton_Click(object sender, RoutedEventArgs e)
{
//2 filter examples I used
bool Agemin = int.TryParse(AgeBoxMin.Text, out int AgeMi);
//first filter
if (Agemin && AgeBoxMin.Text.Length != 0 && (AgeBoxMax.Text.Length == 0 || Agemax != true))
{
filtercount++;
int T = 0; while (T < AgeListNumb.Count)
{
if (AgeListNumb[T] > AgeMi)
{
IndexAge.Add(T);
TotalFilter.Add(T);
}T++;}}
//second filter
if (JobTextBox.Text.Length != 0)
{ filtercount++;
int P = 0; while (P < JobList1.Count)
{ if (JobList1[P].ToLower().Contains(JobTextBox.Text.ToLower()))
{
IndexJob.Add(P);
TotalFilter.Add(P);
}P++;}}
// the filter system: (probable the problem)
var matches = TotalFilter.GroupBy(x => x).Where(x => x.Count() == filtercount).Select(x => x.Key).ToList();
// applying filter to Listbox
if (filtercount != 0 && matches.Any())
{
AccountNamesList.Items.Clear();
foreach (var I in matches)
AccountNamesList.Items.Add(Listboxlist[I]);
}
//(Listboxlist contains random names, those names are created with a function)
}

The first time i run it it runs perfect just as i want it,

But the second time i use the above code it doubles matches

I have looked up what happend with the matches list:

messageBox.Show(Matches.Aggregate("Matches indexes : ", (s1, s2) => s1 + " , " + s2);

If i use the first filter and i allow all items in Listboxlist

to pass( filling in 0 in AgeBoxMin(textbox))

it gives the output:

(If listboxlist would contain 6 items )

1,2,3,4,5,6

If i do it again

I get the output: 1,2,3,4,5,6,7,8,9,10,11,12

for some reason it doubles it and makes the entire program crash

because list box only contains 6 items not 12.

Maybe somehow it stores all the items in "var matches" and adds it all up.

5 Replies

Know the answer? Post it — somebody with the same question will find it here.

Kiran Mohanty5y ago
Accepted answer
Try adding below code. Clear the list before adding anything to it.
public void FilterButton_Click(object sender, RoutedEventArgs e)
        {
TotalFilter.Clear();
//rest all logics that you have
}
osyris zosar5y ago
I have finally solved the problem it was AgeListNumb

the list was not cleared and added more numbers each time I pressed the button
but it would be impossible to figure that out without having the full code
I am sorry for that but i do want to thank anyone that took the effort for helping me
Jignesh Kumar5y ago
In TotalFilter list you are adding twice as per code line no. 17 and 26. Is this Add two place is correct one ?

And one more item you need to check your filtercount++; you need initialize again in second filter.
osyris zosar5y ago
I have done that but still it shows the dubble amount of items i have no clue what to do
Jignesh Kumar5y ago
Hi,

Please check TotalFilter.Add(T); and clear before adding to it.