CODEWITHSUNDEEP
c#.netwpfxamldata-binding
user1687824
user1687824

Reputation: 807

Row number in wpf datagrid row

I have datagrid bound a ICollectionView list object. Basically the rows are filtered based on a value in one column. Now there is a index column in each of the row. This is basically the row number . Since the rows are filtered the row number changes. How to handle this ?

Basically DataGrid is bound to a list of class object.

 Class city
 {
   Int Index;
   String Name;
   string location; 
  }

 List<city> Cities;

When i create the object, index has the value according to the no of items in the index. So the first object will have index =0, second will have index=1 and so on. Index is a column in the grid. Now lets say i have 2 objects with location Dubai. and one with Cairo(3rd object , with Index=3). When i select Cairo Only that row will be displayed. But since i have added the index earlier , index number=3 where as i want it to be 1 since there is only one row after the filter.

Upvotes: 0

Views: 2392

Answers (2)

Carbine
Carbine

Reputation: 7903

You can Use AlternationIndex when you want to show Row Index. Two things are important when you are using AlternationIndex:

  • Set AlternationCount for the control. This is like a counting limit for AlternationIndex after that it will restart from 0 if your number of elements exceeds that count. Ideally you can bind it to Count Of Items if you dont want it to restart from 0
  • When Binding AlternationIndex be mindful of the Source. For ListBox it will be {RelativeSource AncestorType=ListBoxItem} for others it can be {RelativeSource Mode=TemplatedParent}

Try this Sample below:

<ListBox Name="CityListBox" AlterationCount={Binding CountOfItems}
    <ListBox.ItemTemplate>
        <DataTemplate DataType="City">
            <TextBlock>
                    <Run Text="{Binding Name}"></Run>
                    <Run Text=" : "></Run>
                    <Run Text="{Binding Country}"></Run>
                    <Run Text=" : "></Run>
                    <Run Text="{Binding RelativeSource={RelativeSource AncestorType=ListBoxItem},
                                Path=(ItemsControl.AlternationIndex), Mode=OneWay}"></Run>
            </TextBlock>
        </DataTemplate>
    </ListBox.ItemTemplate>
</ListBox>

Output

CityA : CountryA : 0
CityB : CountryB : 1
CityC : CountryC : 2

Upvotes: 2

Jason Loki Smith
Jason Loki Smith

Reputation: 438

what will typically need to do is to set the value for index first, then apply the filter.

include the System.Linq namespace and add the following

cities = cities.Select((item, index) =>
        new city()
        {
            Index = index,
            Name = item.Name,
            location =  item.location
        });

This will bring back a list of cities where the first index would be zero. If you want it to start from one simply change it to :

cities = cities.Select((item, index) =>
        new city()
        {
            Index = index + 1,
            Name = item.Name,
            location =  item.location
        });

After this has been completed you should apply your filter, which shouldn't be overridden unless you are changing the values.

Upvotes: 0

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