Update items count in my Class

Question

Hello
I need your help on the following issue.
I have the following class  in my application
All Countries (properties CountryId, CountryName, CountryCount)
AllIndustries (properties IndustryId, IndustryName, IndustryCount)
I am using: INotifyPropertyChanged for all class.
On my interface, I have two TreeView with Checkbox
treeview for Countries with 193 countries in total
treeview for Industries with 96 industries in total
<HierarchicalDataTemplate DataType="{x:Type localx:AllCountries}" >
<Border BorderBrush="#FFb6b6b6" BorderThickness=" 0,0,0,0" Margin="0,0,0,0" x:Name="brd" >
<Grid>
<StackPanel Orientation="Horizontal" Margin="20,0,0,0" >
<CheckBox x:Name="cbx" Content="{Binding CountryName}" Margin="5" Foreground="White" Click="cbx_singleCountry_Checked" >
</CheckBox>
<TextBlock Text="{Binding CountryCount}" FontSize="13" Padding="5,2,5,2" Foreground="white" HorizontalAlignment="Left" Background="{x:Null}" Width="204" />
</StackPanel>
</Grid>
</Border>
</HierarchicalDataTemplate>
I also have a class AllPeople (properties PeopleID, PeopleName, People Group, People Country, PeopleIndustry)
I display the data from the AllPeople class in a Datagrid
Content of Datagrid varies depending on the choice of a ComboBox
What I want to do:
When the datagrid is filled, the properties "CountryCount" of the class AllCountries  and  "IndustryCount" of  AllIndustries
Class  must be updated for each element of the treeview according to the matching result.
What I have written as code.
for (int c = 0; c < myAllCountries.Count; c++)
MyFilter = new ObservableCollection<AllPeople>(myAllPeople.Where(r => r.PeopleCountry.Equals(myAllCountries[c].CountryName)));
myAllCountries[c].CountryCount = MyFilter.Count;
for (int c = 0; c < myAllIndusties.Count; c++)
MyFilter = new ObservableCollection<AllPeople>(myAllPeople.Where(r => r.PeopleIndusty.Equals(myAllIndusties[c].IndustyName)));
myAllIndusties[c].IndustyCount = MyFilter.Count;
The code works, properties are updated, but I have a performance issue.
It is SLOW.
I display a loading Gif image and i use
Dispatcher.BeginInvoke(new Action(() =>
But the delay is still long and the interface freezes.
How can I avoid this ? or do a something like
public class AllCountries : INotifyPropertyChanged
private ObservableCollection<AllPeople> m_Items;
public ObservableCollection<AllPeople> Items
get { return m_Items; }
set
if(m_Items != null)
m_Items = value;
OnPropertyChanged("Items");
public int ProductCount
// MyAdvancedSearch = new ObservableCollection<PublicCompaniesClass>(_mainWindow.myPbC.Where(r => r.Market.Equals(_mainWindow.myMarket[a].Market_Name) ));
// _mainWindow.myMarket[a].Market_Count = MyAdvancedSearch.Count;
private int _countryId,;
public int CountryId
get { return _countryId,; }
set
if (_countryId, != value)
_countryId, = value;
OnPropertyChanged("CountryId");
private string _countryname;
public string CountryName
get { return _countryname; }
set
if (_countryname != value)
_countryname = value;
OnPropertyChanged("CountryName");
private int _countrycount;
public int CountryCount
get
return Items == null
? 0
: Items.Where(r => r.PeopleCountry.Equals(CountryName)).Count();
set
if (_countrycount != value)
_countrycount = value;
OnPropertyChanged("CountryCount");
public event PropertyChangedEventHandler PropertyChanged;
protected void OnPropertyChanged(string p_strPropertyName)
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(p_strPropertyName));
So,  I will not have to use a For loop to update the properties CountryCount.
Thanks in advance for any help

Answer 1

Hi CPGtech,
Thanks for your post.
I was trying to make a sample according to your description, but I need to confirm something with you first.
>>”Content of Datagrid varies depending on the choice of a ComboBox”
Here what’s the itemsource of ComboBox?  Is it the AllPeople?
>>” But the delay is still long and the interface freezes.”
In my experience, it may due to the consuming operation in your code. I suggest that you could call these methods in “Dispatcher.BeginInvoke()” or you could also create a new thread  with the method.
By the way, could you please post a code sample to show this issue?  Please use your OneDrive and share a link to here.
Best Regards,
Eoro