Difference between revisions of "HowTo:Implement Custom Filtering"

Revision as of 12:41, 20 April 2023

Input field

The input field is just a basic Textbox we are gonna using for inputting the filter criteria value.
It is based on these components:

Grid.Resources to define the style
Textblock with run text
Textbox that serves as an input field

It will look like this:

EvalExpression

With this EvalExpression, we are able to combine the Input text field with the value parameter (property from the item we want to filter).

Here is the final XAML EvalExpression solution:

<controls:EvalExpression x:Name="FilterExpression"
Context="{Binding}"
Expression="FC1">
<controls:EvalExpressionParameter Name="FC1"
Value="{Binding ElementName=InputTextboxName, Path=Text, Converter={StaticResource StringFormatConverter}, ConverterParameter='Item.Values["NAME"].ToLower().Contains("{0}".ToLower())==true'}" />
</controls:EvalExpression>

The best solution would be to place this eval expression into the <Grid.Resources>.

To really get used to this EvalExpression we also need to configure a ListCollectionView, that would look like this:

<cv:ListCollectionView x:Key="FilterView"
Expression="{Binding ElementName=FilterExpression, Path=Result}"
ItemsSource="{Binding PropertyViewModel.FilterQueryResults.Items, Converter={StaticResource CollectionTruncateConverter}, ConverterParameter=200}" />

Example Result

This is an final example how it would look like but with two Filters:

@@ Line 63: / Line 63: @@
                  ItemsSource="{Binding PropertyViewModel.FilterQueryResults.Items, Converter={StaticResource CollectionTruncateConverter}, ConverterParameter=200}" />
 </source>
+== Example Result ==
+This is an final example how it would look like but with two Filters:<br>
+[[File:Editing_Guid_Editing_with_Custom_Filtering.png|400px]]