Binding a DataPager to ComboBox?

Question

I have a comboxbox defined like this (basically):

<ComboBox x:Name="pageViewSize">
    <ComboBox.Items>
        <ComboBoxItem IsSelected="True">5</ComboBoxItem>
        <ComboBoxItem>10</ComboBoxItem>
        <ComboBoxItem>20</ComboBoxItem>
        <ComboBoxItem>30</ComboBoxItem>
        <ComboBoxItem>50</ComboBoxItem>
        <ComboBoxItem>100</ComboBoxItem>
    </ComboBox.Items>
</ComboBox>

Now i would like my DataPager's PageSize (which is the source to a DataGrid) be bound to this ComboBox's SelectedItem.Value (or is it SelectedValue?):

<DataPager PageSize="{Binding Path=SelectedItem.Value, ElementName=pageViewSize}" Source="{Binding PageView}"/>

This, unfortunately, is not working. The initial pagesize is not 10. And whenever i changed the selection in the ComboBox nothing happens to the displayed pagesize in the DataGrid.

What am i doing wrong?

Thanks

Answer 1

From DataPager.PageSize documentation:

The source typically implements the IPagedCollectionView interface. In this case, PageSize gets or sets the IPagedCollectionView.PageSize of the IPagedCollectionView.

If the source is a collection that implements IEnumerablebut not IPagedCollectionView, the DataPager ignores PageSize.

Maybe your data source doesn't properly support PageSize?

---

EDIT: I currently have the same issue as you I had the same issue as you, it was fixed by using @devdigital's answer.

I'm using data binding instead of element binding, on radio buttons + custom converter instead of combo, but it applies in the same way.

What I'm doing is data binding IsChecked to a value in my View Model, with a custom two-way converter checking whether value is equal to converter's parameter.

So here is an example from one of my RadioButtons:

IsChecked="{Binding MyBindedValue, Converter={StaticResource EqualStringConverter}, ConverterParameter=5, Mode=TwoWay}" 

And your DataPager, modified:

<DataPager PageSize="{Binding MyBindedValue, Mode=TwoWay}" Source="{Binding PageView}"/>

Answer 2

Try setting the Mode to TwoWay.

PageSize="{Binding Path=SelectedItem.Value, Mode=TwoWay, ElementName=pageViewSize}"