TextBox is a different element altogether which is outside the Gauge. Gauge consists of lot of elements like Circular scale, Indicators etc. So setting ZIndex in Indicator won't work since TextBox is outside the Gauge. You can try enabling Indicator label as I have mentioned in my last reply.
Thank you very much...
The xaml:
<Grid x:Name="LayoutRoot" Background="White">
<Canvas>
<Canvas.Resources>
<Style x:Key="BarStyle" TargetType="my:NeedleIndicator">
<Setter Property="Canvas.ZIndex" Value="2"></Setter>
</Style>
</Canvas.Resources>
<my:Gauge Name="SLGauges" Height="242" Width="290">
<my:Gauge.Indicators>
<my:NeedleIndicator Name="BI_Value" Style="{StaticResource BarStyle}" ></my:NeedleIndicator> </my:Gauge.Indicators>
<my:Gauge.CircularScales>
<my:CircularScale Minimum="0" Maximum="10000" >
</my:CircularScale>
</my:Gauge.CircularScales>
</my:Gauge>
</Canvas>
<TextBox Height="23" HorizontalAlignment="Left" Margin="101,144,0,0" Name="tb_Value" VerticalAlignment="Top" Width="88" Foreground="#FFD7D9DC" Background="#FF3E4049" Text="" /> </Grid>
Question: Now is to "my: NeedleIndicator" elements (BI_Value) , showed that in the "TextBox" (tb_Value) above. Is the TextBox (tb_Value) on the Canvas element inside it ?