Wpf: Grid: How can i share colum/row height width?

Question

I have a grid with 3 columns and 5 rows:

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="Auto"/>
        <ColumnDefinition Width="Auto"/>
        <ColumnDefinition Width="Auto"/>
    </Grid.ColumnDefinitions>

    <Grid.RowDefinitions>
        <RowDefinition/>
        <RowDefinition/>
        <RowDefinition/>
        <RowDefinition/>
        <RowDefinition/>
    </Grid.RowDefinitions>

    <Label Grid.Row="0" Grid.Column="0">Gas Volume Fraction</Label>
    <TextBox Grid.Row="0" Grid.Column="1" Text="{Binding Path=GasVolumeFraction}" MinWidth="40"></TextBox>
    <Label Grid.Row="0" Grid.Column="2">-</Label>

    <Label Grid.Row="1" Grid.Column="0">Density</Label>
    <TextBox Grid.Row="1" Grid.Column="1" Text="{Binding Path=Density}" MinWidth="40"></TextBox>
    <Label Grid.Row="1" Grid.Column="2">kg/m3</Label>

    <Label Grid.Row="2" Grid.Column="0" Content="Curve speed" Style="{StaticResource curveSpeed}" ></Label>
    <TextBox Grid.Row="2" Grid.Column="1" Text="{Binding Path=Density}" Style="{StaticResource curveSpeed}" MinWidth="40"></TextBox>
    <Label Grid.Row="2" Grid.Column="2" Style="{StaticResource curveSpeed}">rpm</Label>

    <WrapPanel Grid.Row="3" Grid.Column="0" Grid.ColumnSpan="3">
        <RadioButton>Delta pressure</RadioButton>
        <RadioButton>Head</RadioButton>
    </WrapPanel>

    <WrapPanel Grid.Row="4" Grid.Column="0" Grid.ColumnSpan="3">
        <RadioButton>Efficiency</RadioButton>
        <RadioButton>Power</RadioButton>
        <RadioButton>Torque</RadioButton>
    </WrapPanel>

</Grid>

The textboxes and radiobuttons have different space requirements, which makes the rows render with different heights based on their content. How can I make the rows evenly sized, but not larger than whats necessary? In other words: I want the same height as setting Height="Auto" for a row which contains a textbox (the biggest element in my grid) and then use that height for all the rows.

Answer 1

You can use binding to ActualWidth and ActualHeight of your biggest TextBlock.

    <Grid x:Name="grid" ShowGridLines="True">
        <Grid.RowDefinitions>
            <RowDefinition Height="{Binding Path=ActualHeight, ElementName=biggestTB}"/>
            <RowDefinition Height="{Binding Path=ActualHeight, ElementName=biggestTB}"/>                        
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="{Binding Path=ActualWidth, ElementName=biggestTB}"/>
            <ColumnDefinition Width="{Binding Path=ActualWidth, ElementName=biggestTB}"/>                        
        </Grid.RowDefinitions>
        <TextBlock Grid.Row="0" Grid.Column="0" x:Name="biggestTB" Text="biggest textblock content" TextWrapping="Wrap"/>
        <TextBlock Grid.Row="1" Grid.Column="1" Text="content" TextWrapping="Wrap"/>
    </Grid>

Answer 2

Ideally you would use rows with star sizing as you have and set the Grid to VerticalAlignment="Top", but unfortunately star sizing doesn't work when the grid sizes to its content.

Instead of using a single Grid, use a UniformGrid for the vertical layout with nested Grid controls for horizontal layout. You can set a SharedSizeScope on the columns in the inner grids so that the column sizing is shared between them.

<UniformGrid Rows="5" VerticalAlignment="Top" Grid.IsSharedSizeScope="True">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition SharedSizeGroup="A"/>
            <ColumnDefinition SharedSizeGroup="B"/>
            <ColumnDefinition SharedSizeGroup="C"/>
        </Grid.ColumnDefinitions>

        <Label Grid.Column="0">Gas Volume Fraction</Label>
        <TextBox Grid.Column="1" Text="{Binding Path=GasVolumeFraction}" MinWidth="40"></TextBox>
        <Label Grid.Column="2">-</Label>
    </Grid>
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition SharedSizeGroup="A"/>
            <ColumnDefinition SharedSizeGroup="B"/>
            <ColumnDefinition SharedSizeGroup="C"/>
        </Grid.ColumnDefinitions>

        <Label Grid.Column="0">Density</Label>
        <TextBox Grid.Column="1" Text="{Binding Path=Density}" MinWidth="40"></TextBox>
        <Label Grid.Column="2">kg/m3</Label>
    </Grid>
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition SharedSizeGroup="A"/>
            <ColumnDefinition SharedSizeGroup="B"/>
            <ColumnDefinition SharedSizeGroup="C"/>
        </Grid.ColumnDefinitions>
        <Label Grid.Column="0" Content="Curve speed" Style="{StaticResource curveSpeed}"></Label>
        <TextBox Grid.Column="1" Text="{Binding Path=Density}" Style="{StaticResource curveSpeed}" MinWidth="40"></TextBox>
        <Label Grid.Column="2" Style="{StaticResource curveSpeed}">rpm</Label>
    </Grid>
    <WrapPanel>
        <RadioButton>Delta pressure</RadioButton>
        <RadioButton>Head</RadioButton>
    </WrapPanel>
    <WrapPanel>
        <RadioButton>Efficiency</RadioButton>
        <RadioButton>Power</RadioButton>
        <RadioButton>Torque</RadioButton>
    </WrapPanel>
</UniformGrid>