c# wpf datagrid content of column disappears when scrolling but re-appears when scrolling back

Question

I have a DataGrid which is -90 degree rotated and rows of each columns will be added horizontally. I think this is not difficult to understand.

However, if I scroll down the DataGrid, the content of highest position(Top) starts to disappear one by one as scrolling down but re-appears if I scroll up back to there again.

It seems DataGrid throws the passed-column away and tries to focus on current and next column efficiently for good performance.

I don't want content of columns disappears but all the contents show always as usual.

As a reference, My DataGrid only has 6 columns vertically located on left and each column will only have 1 row horizontally. And the content of some rows are long text with 20~ 30 lines.

Here is my simple code and screenshot.

Please help me with excellent advice. Thank you so much ! (Now, here in Far-East Asia is Mid-Night, so, my comment will be available on tomorrow morning)

<DataGrid x:Name="dataGrid_Medicineinformation" HorizontalAlignment="Left" VerticalAlignment="Top" Height="Auto" BorderThickness="0" AutoGenerateColumns="False" UseLayoutRounding="True" RenderTransformOrigin="0.5,0.5" IsReadOnly="True" RowHeight="NaN" RowDetailsVisibilityMode="Collapsed" ColumnWidth="Auto" VerticalScrollBarVisibility="Disabled" CanUserReorderColumns="False" CanUserResizeColumns="False" CanUserSortColumns="False" EnableColumnVirtualization="True">
        <DataGrid.Resources>
            <Style x:Key="DataGridBase" TargetType="Control">
                <Setter Property="LayoutTransform">
                    <Setter.Value>
                        <TransformGroup>
                            <RotateTransform Angle="-90" />
                            <ScaleTransform ScaleX="1" ScaleY="-1" />
                        </TransformGroup>
                    </Setter.Value>
                </Setter>
                <Setter Property="TextOptions.TextFormattingMode" Value="Display" />
            </Style >
            <Style TargetType="DataGridCell" BasedOn="{StaticResource DataGridBase}"/>
            <Style TargetType="DataGridColumnHeader" BasedOn="{StaticResource DataGridBase}"/>
            <Style TargetType="DataGridRowHeader" BasedOn="{StaticResource DataGridBase}"/>

        </DataGrid.Resources>
        <DataGrid.LayoutTransform>
            <TransformGroup>
                <RotateTransform Angle="90" />
                <MatrixTransform Matrix="-1, 0, 0, 1, 0, 0" />
            </TransformGroup>
        </DataGrid.LayoutTransform>
        <DataGrid.RowDetailsTemplate>
            <DataTemplate>
                <StackPanel>
                    <StackPanel.LayoutTransform>
                        <TransformGroup>
                            <RotateTransform Angle="90" />
                            <MatrixTransform Matrix="-1, 0, 0, 1, 0, 0" />
                        </TransformGroup>
                    </StackPanel.LayoutTransform>
                    <TextBlock Height="100" Text="Binding Image" />
                </StackPanel>
            </DataTemplate>
        </DataGrid.RowDetailsTemplate>
        <DataGrid.Effect>
            <DropShadowEffect/>
        </DataGrid.Effect>

        <DataGrid.Columns>
            <DataGridTextColumn Binding="{Binding productname}" Header="제품명" Width="Auto">
                <DataGridTextColumn.ElementStyle>
                    <Style TargetType="{x:Type TextBlock}">
                        <Setter Property="VerticalAlignment" Value="Center"/>
                        <Setter Property="TextAlignment" Value="Left"/>
                        <Setter Property="TextBlock.TextWrapping" Value="Wrap"/>
                        <Setter Property="ToolTip" Value="{Binding Text, RelativeSource={RelativeSource Self}}"/>
                    </Style>
                </DataGridTextColumn.ElementStyle>
            </DataGridTextColumn>
            <DataGridTextColumn Binding="{Binding substancename_korean}" Header="성분명(한글)" Width="Auto">
                <DataGridTextColumn.ElementStyle>
                    <Style TargetType="{x:Type TextBlock}">
                        <Setter Property="VerticalAlignment" Value="Center"/>
                        <Setter Property="TextAlignment" Value="Left"/>
                        <Setter Property="TextBlock.TextWrapping" Value="Wrap"/>
                        <Setter Property="ToolTip" Value="{Binding Text, RelativeSource={RelativeSource Self}}"/>
                    </Style>
                </DataGridTextColumn.ElementStyle>
            </DataGridTextColumn>
            <DataGridTextColumn Binding="{Binding substancename}" Header="성분명(영문)" Width="Auto">
                <DataGridTextColumn.ElementStyle>
                    <Style TargetType="{x:Type TextBlock}">
                        <Setter Property="VerticalAlignment" Value="Center"/>
                        <Setter Property="TextAlignment" Value="Left"/>
                        <Setter Property="TextBlock.TextWrapping" Value="Wrap"/>
                        <Setter Property="ToolTip" Value="{Binding Text, RelativeSource={RelativeSource Self}}"/>
                    </Style>
                </DataGridTextColumn.ElementStyle>
            </DataGridTextColumn>
            <DataGridTextColumn Binding="{Binding dosage}" Header="용법 · 용량" Width="Auto">
                <DataGridTextColumn.ElementStyle>
                    <Style TargetType="{x:Type TextBlock}">
                        <Setter Property="VerticalAlignment" Value="Top"/>
                        <Setter Property="TextAlignment" Value="Left"/>
                        <Setter Property="TextBlock.TextWrapping" Value="Wrap"/>

                    </Style>
                </DataGridTextColumn.ElementStyle>
            </DataGridTextColumn>
            <DataGridTextColumn Binding="{Binding efficacy}" Header="효능 · 효과" Width="Auto">
                <DataGridTextColumn.ElementStyle>
                    <Style TargetType="{x:Type TextBlock}">
                        <Setter Property="VerticalAlignment" Value="Top"/>
                        <Setter Property="TextAlignment" Value="Left"/>
                        <Setter Property="TextBlock.TextWrapping" Value="Wrap"/>

                    </Style>
                </DataGridTextColumn.ElementStyle>
            </DataGridTextColumn>
            <DataGridTextColumn Binding="{Binding precautions}" Header="사용상의 주의사항" Width="Auto">
                <DataGridTextColumn.ElementStyle>
                    <Style TargetType="{x:Type TextBlock}">
                        <Setter Property="VerticalAlignment" Value="Top"/>
                        <Setter Property="TextAlignment" Value="Left"/>
                        <Setter Property="TextBlock.TextWrapping" Value="Wrap"/>
                    </Style>
                </DataGridTextColumn.ElementStyle>
            </DataGridTextColumn>
        </DataGrid.Columns>
    </DataGrid>

Answer 1

My situation consists of 2 matters as horizontal DataGrid and Virtualization. Somebody provided a solution linked on https://social.msdn.microsoft.com/Forums/vstudio/en-US/4b95587d-df29-45db-b265-8c3bab77f2a4/c-wpf-virtualization-datagrid-content-of-column-disappears-when-scrolling-but-reappears-when?forum=wpf

I hope this helps someone else.

Answer 2

Seems like problem with the virtualization. Can you try switching virtualization off by setting

VirtualizingStackPanel.IsVirtualizing = "false", VirtualizingStackPanel.VirtualizationMode="Standard" and EnableColumnVirtualization="false"

on your datagrid and check if this behaviour stays.