RadTrackBar with threshold

[Matthew]

I'm trying to configure the track bar with a threshold value that is greater than the min and less than the max, the user can only go past the threshold value by holding the Control key will dragging the slider. I have tried resetting the value in the Scroll event, that didn’t prevent the slider from continuing or change the value; I reset the value in the ValueChanged event, this did not prevent the slider from continuing but it did reset the value back to the threshold once the mouse was lifted.

I was hoping to have a hard stop at the threshold, is this something that is possible?

Thanks

[Ivan Todorov]

Hi Matthew,

Thank you for contacting us.

Yes, it is possible to achieve such behavior. To do so, you need to listen for changes to the RadTrackBarElement.ValueProperty and apply the threshold if this is needed. The following code snippet demonstrates this:

public Form1()
{
    InitializeComponent();
    this.radTrackBar1.TrackBarElement.RadPropertyChanged += new Telerik.WinControls.RadPropertyChangedEventHandler(TrackBarElement_RadPropertyChanged);
}

int threshold = 50;
void TrackBarElement_RadPropertyChanged(object sender, Telerik.WinControls.RadPropertyChangedEventArgs e)
{
    if (e.Property == RadTrackBarElement.ValueProperty)
    {
        if (Control.ModifierKeys != Keys.Control)
        {
            if (this.radTrackBar1.Value > threshold)
            {
                this.radTrackBar1.Value = Math.Min(this.radTrackBar1.Value, threshold);
                this.radTrackBar1.TrackBarElement.RangeValue = Math.Min(this.radTrackBar1.Value, threshold) - this.radTrackBar1.Minimum;
                this.radTrackBar1.PerformLayout();
            }
        }
    }
}

I hope you find this useful. If you have any further questions, do not hesitate to write back.

Regards,
Ivan Todorov
the Telerik team