Refresh (or invalidate?) SfChart

[Juliano Franz]

Hello,
is it possible to force a redraw of a sfchart?

In one application I have a itemsource that is not an observable collection (lets say a standard list for now) therefore it does notify changes.
After I create the chart I load data from a database in the background. I would like to tell the chart to update once I finish loading from the background task.

One way to do it is to create the series with a null itemsource and then once I finish loading set the itemsource. I do not like this idea because it does not allows me to to refresh the chart every 10% of the data load for example.

Is there a method for me to call chart.Refresh() or something similar?

Thanks!

[Muneesh Kumar G]

Hi Juliano 

 

Thanks for using Syncfusion products.  

 

We can able to achieve your requirement by calling UpdateArea method in SfChart as follows.  

 

Code snippet [C#]  

 

 

MethodInfo info = chart.GetType().GetMethod("UpdateArea", 

                                BindingFlags.NonPublic | BindingFlags.Instance, 

                                null, 

                                new Type[] { typeof(bool) }, 

                                null); 

 

info?.Invoke(chart, new object[] { true }); 

 

 

Please let us know if you have any queries.  

 

Thanks, 

Muneesh Kumar G. 

[Juliano Franz]

Hi Muneesh,
sorry for this long delay. I got sucked into other projects for a while =]

Your solution did worked for me. Here is what a I have:

• A async TCP client that receives data updates and stores into a List<DataType>
• A number of series that have the ItemSource set to that list
• A DispatcherTimer that calls the following refresh method every n seconds (could not figure out how to add code)

        public void RefreshPlot()
        {
            var info = Chart.GetType().GetMethod("UpdateArea", BindingFlags.NonPublic | BindingFlags.Instance, null,
                new[] {typeof(bool)}, null);

            info?.Invoke(Chart, new object[] { true });

          Console.WriteLine(((ICollection)Chart.Series[0].ItemsSource).Count);

     }

The Count does increase every time I call refresh plot however the chart is not updated. No extra points are added to the screen. Any other suggestions?

Thanks!

[Durgadevi Selvaraj]

Hi Juliano, 

 

Thanks for your update. 

 

We have analyzed the reported problem. Please call the OnBindingPathChanged method instead of UpdateArea method after changing the collection. Please refer the below code, 

 

Code Snippet[C#] 

 

MethodInfo methodInfo = chart.Series[0].GetType().GetMethod("OnBindingPathChanged", 

                                BindingFlags.NonPublic | BindingFlags.Instance); 

methodInfo?.Invoke(chart.Series[0], new object[] { null }); 

Please let us know if you need any further assistance on this. 

 

Regards, 

Durgadevi.S 

[Juliano Franz]

Hi Durgadevi,
It works like a charm! Not sure about performance yet =]
I have ~50 series. To avoid multiple reflection calls I am storing all the MethodInfo in a list. But I still need to iterate over the list to call the method for each series every RefreshInterval.

Anyway, it works =]

Cheers

[Muneesh Kumar G]

Hi Juliano, 

Thanks for the update.

We are glad to know that the given solution works. Please let us know if you need any further assistance.

Thanks,
Muneesh Kumar G.

[Diogo Marinho Araujo]

What is this 'chart' coming from?

[Suyamburaja Jayakumar]

Hi Diogo Marinho Araujo, 

 

We were not clear about exact need, please share the expectation in detailed presentation. Which is more helpful us to find your exact requirement and provide a possible solution at earlier. 

 

Regards, 

Suyamburaja J.