DataGrid添加进度条列

 <DataGrid  x:Name="mygrid" VerticalAlignment="Top"  AutoGenerateColumns="False" Foreground="White" Background="Transparent" Margin="0,20,0,0"
        RowBackground="Transparent" GridLinesVisibility="All"  HorizontalGridLinesBrush="Transparent" VerticalGridLinesBrush="Transparent"  BorderBrush="Transparent"
        VerticalContentAlignment="Center" HorizontalContentAlignment="Center"   FontSize="14.5"  RowHeaderWidth="0" HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Hidden"
         EnableColumnVirtualization="True" EnableRowVirtualization="True" ItemsSource="{Binding UnitHost}" ColumnHeaderStyle="{StaticResource ParkColumnHeader}">
        <DataGrid.Resources>
            <SolidColorBrush x:Key="{x:Static SystemColors.InactiveSelectionHighlightBrushKey}" Color="Yellow"/>
        </DataGrid.Resources>
        <DataGrid.RowStyle>
            <Style TargetType="DataGridRow">
                <Setter Property="Height" Value="40"></Setter>
            </Style>
         </DataGrid.RowStyle>
         <DataGrid.Columns>
             <DataGridTextColumn Header="停车场名称" Width="200"  Binding="{Binding name}" ElementStyle="{StaticResource ResourceKey=DataGridTextColumnCenterSytle}"/>
             <DataGridTextColumn Header="已使用" Width="110"  Binding="{Binding used}" ElementStyle="{StaticResource ResourceKey=DataGridTextColumnCenterSytle}"/>
             <DataGridTextColumn Header="未使用" Width="110"  Binding="{Binding notused}" ElementStyle="{StaticResource ResourceKey=DataGridTextColumnCenterSytle}"/>
             <DataGridTemplateColumn  Header="使用占比" Width="200" >
                 <DataGridTemplateColumn.CellTemplate>
                     <DataTemplate>
                         <ProgressBar Value="{Binding ratio}" Background="#4C717171" BorderBrush="Transparent" Height="20"/>
                     </DataTemplate>
                  </DataGridTemplateColumn.CellTemplate>
              </DataGridTemplateColumn>
              <DataGridTextColumn Header=" " Width="80" Binding="{Binding ratioValue}" Foreground="#ec6941"  ElementStyle="{StaticResource ResourceKey=DataGridTextColumnCenterSytle}"/>
         </DataGrid.Columns>
</DataGrid>