How I can draw a circle in WPF (without code-behind) using min(width, height)/2
as radius?
you can do it in pure XAML you just need to use Binding for the values. You also have to make sure that everything is named
<Grid Name="grdMain">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="75" Name="Col1" />
<ColumnDefinition Width="100" Name="Col2" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="75" Name="Row1" />
<RowDefinition Height="100" Name="Row2" />
</Grid.RowDefinitions>
<Ellipse Grid.Column="1" Grid.Row="1"
Canvas.Top="50"
Canvas.Left="50"
Fill="#FFFFFF00"
Height="{Binding RowDefinitions/ActualHeight, ElementName=Row1, Mode=OneWay}"
Width="{Binding ColumnDefinitions/ActualWidth, ElementName=Col1, Mode=OneWay}"
StrokeThickness="5"
Stroke="#FF0000FF"/>
</Grid>
Where does width and height come from? Example XAML for a circle is:
<Canvas Background="LightGray">
<Ellipse
Canvas.Top="50"
Canvas.Left="50"
Fill="#FFFFFF00"
Height="75"
Width="75"
StrokeThickness="5"
Stroke="#FF0000FF"/>
</Canvas>
A circle is just an Ellipse where Height = Width.