[B.O.B.]

in reply to: Can I use a ValueConverter to set a field value based on other fields? #50437

I wrote some cell template resources to be applied to specific columns. One of which was to take a value that was coming in as an enum and passing it to a value converter to format it into a nice string format. The same should work for you.

Here’s the template:

        <DataTemplate x:Key="EnumCellTemplate">
            <Grid>
                <TextBlock x:Name="txt"
                           VerticalAlignment="Center"
                           TextTrimming="CharacterEllipsis">
                    <TextBlock.Style>
                        <Style TargetType="{x:Type TextBlock}">
                            <Setter Property="Text"
                                    Value="{Binding Converter={StaticResource EnumStr}}" />
                        </Style>
                    </TextBlock.Style>
                </TextBlock>
            </Grid>
        </DataTemplate>

Then in the Columns definition of the DataGridControl, you just have to define the column and set the CellContentTemplate. Something like:

<g:DataGridControl.Columns>
   <g:Column CellContentTemplate="{StaticResource EnumCellTemplate}" FieldName="MyEnumField" />

You can use the above to do all kinds of things – not just change d to surprise. For instance, I have another cell template that takes the value and uses that to return an ImageBrush that gets applied to a Canvas so I can display an image based on the value.

[B.O.B.]

in reply to: Master-Detail hide expander on empty details section #50430

I made a little progress on this one. I added a readonly property called HasChildRows to master item class that returns true if the count of the child binding list > 0.

I then was able to use FindAncestor and bind to the parent DataRow.DataContext.HasChildRows. This works, technically.

                                  Visibility="{Binding Mode=OneWay,
                                                       RelativeSource={RelativeSource Mode=FindAncestor,
                                                                                      AncestorType={x:Type g:DataRow}},
                                                       Path=DataContext.HasChildRows,
                                                       Converter={StaticResource BooleanToVisibilityConverter}}"

^ the problem with the above is at runtime, Visual Studio has a silent binding error for every new row that gets loaded:

System.Windows.Data Error: 4 : Cannot find source for binding with reference ‘RelativeSource FindAncestor, AncestorType=’Xceed.Wpf.DataGrid.DataRow’, AncestorLevel=’1”. BindingExpression:Path=DataContext.HasChildRows;

^ So it looks like binding is failing (at least at first) then succeeding. Is there a better way to bind so it isn’t failing at first. I’m just worried about performance if there is a bunch of rows from the master table are returned in query and every single row is going to initially fail it’s binding.

[B.O.B.]

in reply to: Master-Detail hide expander on empty details section #50426

XAML code with the less than/greater than chars replaced with html codes:

                    <g:TableView.ExpandGroupGlyph>
                        <DataTemplate>
                            <!--  Not sure why the wonkiness, but getting the icon centered required a weird margin + wrapper grid.  -->
                            <Grid x:Name="grd"
                                  Width="24"
                                  VerticalAlignment="Stretch"
                                  Background="Transparent">
                                <Grid.Effect>
                                    <DropShadowEffect BlurRadius="0"
                                                      RenderingBias="Performance"
                                                      ShadowDepth="1" />
                                </Grid.Effect>
                                <Border x:Name="brd"
                                        Width="16"
                                        Height="16"
                                        Margin="3,12"
                                        VerticalAlignment="Center"
                                        BorderBrush="LightGray"
                                        BorderThickness="1">
                                    <Border.Style>
                                        <Style>
                                            <Style.Triggers>
                                                <DataTrigger Binding="{Binding ElementName=grd,
                                                                               Path=IsMouseOver}"
                                                             Value="True">
                                                    <Setter Property="Border.Background"
                                                            Value="{DynamicResource appIconColor}" />
                                                </DataTrigger>
                                            </Style.Triggers>
                                        </Style>
                                    </Border.Style>
                                    <Path Width="10"
                                          Height="10"
                                          Margin="1"
                                          Data="M0,5 H10 M5,5 V10Z"
                                          Stroke="White"
                                          StrokeThickness="2" />
                                </Border>
                            </Grid>
                        </DataTemplate>
                    </g:TableView.ExpandGroupGlyph>

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