Ability to lock handle?

[Nicole]

I am using a RadSlider to set the date range for a separate chart as follows:

<telerik:RadSlider x:Name="sldTimeSelection" Grid.Row="1" Grid.Column="0" Orientation="Horizontal"  

                   Minimum="-365" Maximum="0" IsMoveToPointEnabled="True"

                   IsSelectionRangeEnabled="True" MinimumRangeSpan="7" MaximumRangeSpan="365" 

                   SelectionStart="-30" SelectionEnd="0"

                   IsSnapToTickEnabled="True" TickPlacement="BottomRight" Ticks="-7, -30, -90, -180, -365" 
                                                    EnableSideTicks="False" Margin="5,0" >

</telerik:RadSlider>

Is there any way to lock the Increase Handle into it's position at 0?  We do not, at this time, wish to enable the customer to look at a range of historical data, but the customer likes the look of the rage versus the look of a single thumb selection.

I could ignore the increase handle value and reset it back to 0 in the event handler, but I don't think this would be user friendly and might cause frustration.

[Kiril Stanoev]

Hi Nicole,

 Try setting the AlternateThumbStyle with an IsEnabled setter:

<telerik:RadSlider>
    <telerik:RadSlider.AlternateThumbStyle>
        <Style TargetType="Thumb">
            <Setter Property="IsEnabled" Value="False" />
        </Style>
    </telerik:RadSlider.AlternateThumbStyle>
</telerik:RadSlider>

Give it a try and let me know if this works for you.

Greetings,
Kiril Stanoev
the Telerik team

[Nicole]

Thanks for the idea, Kiril.  I get an error that "the attachable property 'AlternateThumbStyle' was not found in type RadSlider'

It looks like this was added in 2011.3, but we are on 2011.2.290.1040 and I am not allowed to upgrade versions.  Are you aware of a work-around for 2011.2?

[Kiril Stanoev]

Hi Nicole,

In this case you will have to traverse the visual tree of RadSlider and find the desired thumb.

<telerik:RadSlider x:Name="slider1" Loaded="slider1_Loaded" IsSelectionRangeEnabled="True" />

private void slider1_Loaded(object sender, RoutedEventArgs e)
{
    this.Dispatcher.BeginInvoke(() =>
    {
        var selectionStartThumb = this.slider1.ChildrenOfType<Thumb>().Where(thumb => thumb.Name == "RangeStartThumb").FirstOrDefault();
        if (selectionStartThumb != null)
        {
            selectionStartThumb.IsEnabled = false;
        }
    });
}

Give it a try and let me know if it works. I'd be glad to further assist you.

Regards,
Kiril Stanoev
the Telerik team

[Nicole]

I modified this a bit to get rid of a "not a delegate type" error as follows:

this.Dispatcher.BeginInvoke((Action)(() =>
{
    var selectionStartThumb = this.sldTimeSelection.ChildrenOfType<Thumb>().Where(thumb => thumb.Name == "RangeStartThumb").FirstOrDefault();
    if (selectionStartThumb != null)
    {
        selectionStartThumb.IsEnabled = false;
    }
}));

However, I am still getting an error that "The type or namespace name 'Thumb' could not be found."  The project and .cs both reference Teleriks.Windows.Controls. 

Do I need another reference, or is the type maybe incorrect?  I don't see anything in intellisense that looks close.

[Kiril Stanoev]

Hi Nicole,

 I am not sure what might be causing this issue, but it smells like it has something to do with namespaces. However I need more information because I am not sure what might be causing the issue.

Kind regards,
Kiril Stanoev
the Telerik team

[Nicole]

Hi Kiril,

What kind of information would help?  Here's my using section:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.IO.IsolatedStorage;
using Dashboard.Silverlight.SystemDetailsService;
using Telerik.Windows.Controls;
using Dashboard.Silverlight.SupportClasses;
using System.Windows.Browser;
using Telerik.Windows.Controls.GridView;
using Dashboard.Silverlight.Views.Aviation;
using Telerik.Windows.Controls.Charting;

[Kiril Stanoev]

Hello Nicole,

Could you please try the following approach and let me know if it helps.

this.Dispatcher.BeginInvoke((Action)(() =>
{
    var selectionStartThumb = this.sldTimeSelection.ChildrenOfType<System.Windows.Controls.Primitives.Thumb>().Where(thumb => thumb.Name == "RangeStartThumb").FirstOrDefault();
    if (selectionStartThumb != null)
    {
        selectionStartThumb.IsEnabled = false;
    }
}));

 

Regards,
Kiril Stanoev
the Telerik team

[Nicole]

Thanks, that works great.  It locked down the wrong thumb but I changed that easily.

this.Dispatcher.BeginInvoke((Action)(() =>
{
    var selectionEndThumb = this.sldTimeSelection.ChildrenOfType<System.Windows.Controls.Primitives.Thumb>().Where(thumb => thumb.Name == "RangeEndThumb").FirstOrDefault();
    if (selectionEndThumb != null)
    {
        selectionEndThumb.IsEnabled = false;
    }
}));