Home / Community / Forums / WPF > Chart > Removing a Series/DataPoints from a series

• Brian Seay

  Posted on Apr 27, 2009 (permalink)

  Hi 

  
  

  I'm working with the WPF controls and trying to build an application to display call data on a screen.

  
  

  My screen has 2 charts, the first of which is a line graph showing call volume over time.   In this, I add a new data point to a series as the day progresses - this works OK.

  
  

  The second chart is a summary of all calls by a business area.   Therefore, it is possible that all the data points on this chart could change.  Therefore I would either need to refresh or remove and add the data points.  I cannot find anything in documentation or examples to suggest how this could be done.

  
  

  There seems to be a Remove() method on the DataSeries object, but this takes a DataPoint object - so therefore I wrote code to enumerate the data points in a series and attempt to remove them :

  
  

      

  DataSeries inboundBarSeries = new DataSeries();

  DataSeries outboundBarSeries = new DataSeries();

  inboundBarSeries.Definition = new BarSeriesDefinition();

  outboundBarSeries.Definition = new BarSeriesDefinition();

  inboundBarSeries.Label = "Inbound";

  outboundBarSeries.Label = "Outbound";

  skillBarChart.DefaultView.ChartArea.DataSeries.Add(inboundBarSeries);

  skillBarChart.DefaultView.ChartArea.DataSeries.Add(outboundBarSeries);

  }

  public void PopulateSkillChart()

  {

  foreach(DataPoint dp in skillBarChart.DefaultView.ChartArea.DataSeries[0])

  {

  skillBarChart.DefaultView.ChartArea.DataSeries[0].Remove(dp);

  }

  DataSeries inboundBarSeries = skillBarChart.DefaultView.ChartArea.DataSeries[0];

  DataSeries outboundBarSeries = skillBarChart.DefaultView.ChartArea.DataSeries[1];

  this.loadInboundSkillChart(inboundBarSeries, outboundBarSeries);

  }

  
  

  The first chunk of code runs once when the screen is initialised, and adds the empty series to the chart.  The PopulateSkillChart code then runs on a periodic basis and is intended to remove the data points and re-add them.  However this code fails with "Collection was modified; enumeration operation may not execute." when I try and execute it.

  
  

  Would this be recommended as a way to refresh the data set or is there an easier method which I am missing?

  
  

  I would appreciate your help on this.

  
  

  Thanks

  
  

  Richard

  
  

  Reply

• Answer Telerik Admin

  Posted on May 1, 2009 (permalink)

  Hi Brian Seay,
  
  

  The error you are getting is because you cannot modify a collection inside a foreach loop. The easiest way to clear the data series from RadChart is simply to call: skillBarChart.DefaultView.ChartArea.DataSeries.Clear();
  
  All the best,
  Vladimir Milev
  

  Reply

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