如何在编写 WPF 单元格样式时停止工具提示

Question

I am currently working on a an App with a colleague that displays quarterly account figures in a data grid. There are some checks that are done on certain columns to see if there are over/under certain thresholds.

My colleague built the horizontal Data Grid view/layout (columns are rotated and displays cells left to right)and my task is to format the text and add tool tips to the cells where checks were performed and failed. Thus highlighting on the cell there is issue with the value.

The default cells style is:

<Style TargetType="{x:Type DataGridCell}">
            <Setter Property="Focusable" Value="False" />
            <Setter Property="IsTabStop" Value="False" />
            <Setter Property="LayoutTransform">
                <Setter.Value>
                    <TransformGroup>
                        <RotateTransform Angle="-90"/>
                        <ScaleTransform ScaleX="1" ScaleY="-1" />
                    </TransformGroup>
                </Setter.Value>
            </Setter>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type DataGridCell}">
                        <Grid Background="{DynamicResource AppGlobalBackground}">
                            <ContentPresenter VerticalAlignment="Center"
                                              HorizontalAlignment="Left"/>
                            <TextBlock>
                                <ContentPresenter Margin="0,2,10,2"/>
                            </TextBlock>
                        </Grid>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>

            <Style.Triggers>
                <Trigger Property="IsSelected" Value="True">
                    <Setter Property="Background" Value="{DynamicResource AppGlobalBackground}" />
                    <Setter Property="Foreground" Value="{DynamicResource AppGlobalForeground}" />
                    <Setter Property="BorderBrush" Value="{DynamicResource AppGlobalBackground}" />
                </Trigger>

                <Trigger Property="IsFocused" Value="True">
                    <Setter Property="IsSelected" Value="True" />
                </Trigger>
            </Style.Triggers>
        </Style>

The Data Grid behaves as expected without the tooltip

 <DataGridTextColumn Binding="{Binding Tax}" >
   <DataGridTextColumn.HeaderTemplate >
            <DataTemplate>
                  <TextBlock Text="{Binding DataContext.ViewLabels.Tax,  RelativeSource= 
                                    RelativeSource AncestorType=DataGrid}}" />
           </DataTemplate>
    </DataGridTextColumn.HeaderTemplate>

However, once a tool tip is added it overrides the Cell style and rotates the data in the cell

                        <DataGridTextColumn Binding="{Binding Tax}" >
                        <DataGridTextColumn.HeaderTemplate >
                            <DataTemplate>
                                <TextBlock Text="{Binding DataContext.ViewLabels.Tax,  RelativeSource={RelativeSource AncestorType=DataGrid}}" />
                            </DataTemplate>
                        </DataGridTextColumn.HeaderTemplate>

                        <DataGridTextColumn.CellStyle>
                            <Style TargetType="DataGridCell" >
                                <Setter Property="ToolTip" >
                                    <Setter.Value>
                                        <ToolTip Visibility="{Binding Path=TaxTT, Converter={StaticResource StringToVisibleTT}}" >
                                            <TextBlock Text="{Binding TaxTT}" />
                                        </ToolTip>
                                    </Setter.Value>
                                </Setter>
                                <Setter Property="Foreground" Value="{Binding Path=TaxTT,  Converter={StaticResource FormattingConverterTT}}"/>
                            </Style>
                        </DataGridTextColumn.CellStyle>
                    </DataGridTextColumn>

note The visibility converter checks if the tool tip (TaxTT) is an empty string or not & the format converter turns the text red (if the tool tip has text).

I have read quite a few stack overflow articles about visual trees, but haven't been able to find one that stops it from overriding the normal cells. Is it at all possible?

Answer 1

custom CellStyle should inherit base style for DataGridCell:

<DataGridTextColumn.CellStyle>
    <Style TargetType="DataGridCell" BasedOn="{StaticResource {x:Type DataGridCell}}">
        <Setter Property="ToolTip" >
            <Setter.Value>
                <ToolTip Visibility="{Binding Path=TaxTT, Converter={StaticResource StringToVisibleTT}}" >
                    <TextBlock Text="{Binding TaxTT}" />
                </ToolTip>
            </Setter.Value>
        </Setter>
        <Setter Property="Foreground" Value="{Binding Path=TaxTT,  Converter={StaticResource FormattingConverterTT}}"/>
    </Style>
</DataGridTextColumn.CellStyle>