Radzen Chart: Reload Data

Radzen.Blazor Components
1

Hey I have a Radzen line chart, where the data source is a List<>. Every second, I add data to the list and call an reload for the chart. My problem is that the Chart wont update, no mater what i do.

2

You need to either call the Reload method of the chart or update the list variable e.g. list = liist.ToList().

3

Its allready a List and the Reaload function has no effect.

4

I tried the following and it seems to work as expected:

<RadzenChart @ref=@chart SeriesClick=@OnSeriesClick>
  <RadzenPieSeries Data="@revenue" Title="Revenue" CategoryProperty="Quarter"
        ValueProperty="Revenue" />
</RadzenChart>
<RadzenButton Text="Add" Click=@OnClick />
@code {
    RadzenChart chart;

    void OnClick()
    {
        revenue.Add(new DataItem
        {
            Quarter = $"Q{revenue.Count}",
            Revenue = revenue.Count * 10000
        });

        chart.Reload();
    }

    class DataItem
    {
        public string Quarter { get; set; }
        public double Revenue { get; set; }
    }

    List<DataItem> revenue = new List<DataItem> {
new DataItem
{
Quarter = "Q1",
Revenue = 30000
},
new DataItem
{
Quarter = "Q2",
Revenue = 40000
},
new DataItem
{
Quarter = "Q3",
Revenue = 50000
},
new DataItem
{
Quarter = "Q4",
Revenue = 80000
},
};
}

chart-update

5

I have it like this and it dont work

<RadzenChart @ref="myChart">
    <RadzenLineSeries Data="viewmodell.MeasureItems" CategoryProperty="Time" Title="2019" LineType="LineType.Dashed" ValueProperty="Percentage">
        <RadzenMarkers MarkerType="MarkerType.Square" />
    </RadzenLineSeries>
</RadzenChart>

@code {
RadzenChart myChart;
..
..
..
 private async void ViemodelPropertyChanged(object sender, PropertyChangedEventArgs e)
    {
        await InvokeAsync(() =>
        {
            try
            {
                myChart.Reload();
                StateHasChanged();
            }
            catch (ObjectDisposedException disposed)
            {
                //Todoo: 
            }
        });
    }

And the ViewModdel Class with the List

....
    public List<MeasureItem> MeasureItems 
        { get 
            {
                return measureItems;
            } 
            set
            {
                measureItems = value;
            }
        }
....
6

This is an anti pattern and should not be used. Try making it async Task. Also if there is an ObjectDisposedException things won't work for sure.

I have attached a working demo - you can start from it.

7

I have to use async void because i subscribe the methode to an event.
The Reload() is called right, so the ObjectDisposedException is not the problem