Chart View w/ Legend and Tool Tip Text

[Mark]

Is there a way to add Tool Tip Text to the legend items that get generated?  I have Tool Tip Text on the Series object, but I would like it on the Legend Items as well. 

Also, one other question, is there a way to customize how the legend shows the value next to the key?  Right now, our legand keys are "ABC 123".  I would like to add a "-" between the KEY and the COUNT value. 

 

TIA

 

[Nadya | Tech Support Engineer]

Hello, Mark,

Yes, you can add a tooltip to the legend items. You can use the ToolTipTextNeeded event and show the desired text when hovering legend items:

private void RadChartView1_ToolTipTextNeeded(object sender, ToolTipTextNeededEventArgs e)
{
    LegendItemTitle legendItem = sender as LegendItemTitle;
    if (legendItem != null)
    {
        e.ToolTipText = legendItem.Text;
    }
}

According to your second question, if I understand you correctly you would like to customize the legend item title text. Please refer to the following code snippet:

this.radChartView1.ChartElement.LegendElement.Items[0].Title = "ABC-123";

More information about legend in RadChartView is available here: Legend - ChartView - Telerik UI for WinForms 

I hope this helps. Should you have any other questions do not hesitate to contact me.

Regards,
Nadya | Tech Support Engineer
Progress Telerik

[Mark]

For the second part, is there an event that is called when these LEGEND ITEMS are generated so I can update them as I need them. I looked for something, just didn't find it, and maybe I am looking in the wrong area.

[Mark]

and the first part, while this gets me close, I actually want to use a different value, so I have no way to get to the DATAITEM it is related to....I will keep looking

[Mark]

So, after digging around a little bit more and reading more in the help/docs link you provided, I am using the VisualItemCreating event to set the label and tooltip text as needed.  However, I am getting TEXT overlap and I am not sure why.

 

Here is my code

      private void HandleLegendElementVisualItemCreating(object sender, LegendItemElementCreatingEventArgs e)
      {
         e.ItemElement = new NtsLegendItemElement(e.LegendItem);
      }

Here is my class, similar to the class in the example.

namespace Nts.Suite
{
   public class NtsLegendItemElement : LegendItemElement
   {
      #region Public Constructors

      public NtsLegendItemElement(LegendItem item) : base(item)
      {
         if (item.Element is DataPointElement dataPointElement)
         {
            if (dataPointElement.DataPoint.DataItem is ChartResults myResults)
            {
               ToolTipText = myResults.ToolTipText;
               Text = $"{myResults.Category} ({myResults.Value:N0})";
            }
         }
      }

      #endregion Public Constructors

      #region Protected Methods

      protected override void Synchronize()
      {
         base.Synchronize();
         SyncVisualStyleProperties(LegendItem.Element, TitleElement);

      }

      #endregion Protected Methods
   }
}

 

This is my results

 

 

[Mark]

Okay, I think I have it figured out.   Took a little trial and error, but I got it.   

this is my updated CustomLegendItemElement class.  This works perfectly

 

 public class NtsLegendItemElement : LegendItemElement
   {
      #region Public Constructors

      public NtsLegendItemElement(LegendItem item) : base(item)
      {
         if (item.Element is DataPointElement dataPointElement)
         {
            if (dataPointElement.DataPoint.DataItem is ChartResults myResults)
            {
               TitleElement.ToolTipText = myResults.ToolTipText;
               item.Title = $"{myResults.Category} ({myResults.Value:N0})";
            }
         }
      }

Here are my results (shown with ToolTipText) :)

 

 

[Nadya | Tech Support Engineer]

Hello, Mark,

It seems that you managed to solve the problem you had with text overlapping. I am glad that your tooltips and custom NtsLegendItemElement are working fine. In case you have any other difficulties do not hesitate to contact us.