Gauge chart doesn't refresh dynamically ranges

[Anatoly Chekh]

Hello!

I have an issue. I try to change scale ranges dynamically, but it doesn't changed (old range is shown).
This is simple app where it doesn't work:

Xaml:

<StackPanel>
            <telerik:RadRadialGauge Width="220" Height="220">
                <telerik:RadialScale Name="scale"
                                         RangeLocation="Outside"
                                         RangeOffset="-0.015"
                                         MajorTickOffset="-0.015"
                                         MiddleTickOffset="-0.015"
                                         MinorTickOffset="-0.015"
                                         LabelRotationMode="None">
                    <telerik:RadialScale.Ranges>
                        <telerik:GaugeRange Min="0" Max="20" StartWidth="0.015" EndWidth="0.015" Background="Green"  />
                    </telerik:RadialScale.Ranges>
                </telerik:RadialScale>
            </telerik:RadRadialGauge>
            <Button Content="Click" Click="ButtonBase_OnClick" />
        </StackPanel>

Click action is very simple:

private void ButtonBase_OnClick(object sender, RoutedEventArgs e)
{
     scale.Ranges.Clear();
     scale.Ranges.Add(new GaugeRange() { Min = 20, Max = 40, StartWidth = 0.015, EndWidth = 0.015, Background = new SolidColorBrush(Colors.Green) });
}

After buttin click I see old range from 0 to 20. If I call scale.InvalidateMeasure(); then I get new range from 20 to 40, but also I still see old range from 0 to 20.

Is is a bug or I'm doing something wrong?

Thanks, Anatoly Chekh.

[Andrey]

Hello Anatoly,

We are aware of a problem with Clear method. The problem is in the implementation of this method in the standard DependencyObjectCollection and code in the gauge control which relies on it. We created a fix for this problem already. We extended the collection which implements the IList interface with RemoveAll method which should be used instead of Clear method. Note, the extension is included into the Telerik.Windows.Controls.Map namespace in the same Telerik.Windows.Controls.DataVisualization.dll assembly.
The sample code is below.

using System.Windows;
using System.Windows.Controls;
using Telerik.Windows.Controls.Gauge;
using Telerik.Windows.Controls.Map;
using System.Windows.Media;

namespace GaugeRangeVisibility
{
    public partial class MainPage : UserControl
    {
        public MainPage()
        {
            InitializeComponent();
        }

        private void ButtonBase_OnClick(object sender, RoutedEventArgs e)
        {
            scale.Ranges.RemoveAll();
            scale.Ranges.Add(new GaugeRange()
            {
                Min = 20,
                Max = 40,
                StartWidth = 0.015,
                EndWidth = 0.015,
                Background = new SolidColorBrush(Colors.Green)
            });

            scale.InvalidateMeasure();
        }
    }
}

Kind regards,
Andrey Murzov
the Telerik team