To save synchronously to a Nevron Binary Chart local file call the SaveToLocalFile method of the chart view. This method doesn't work on sandboxed platforms like Blazor WebAssembly.

chartView.SaveToLocalFile(@"D:\Documents\MyChart.ncb");

To save a chart to a file asynchronously call the SaveToFileAsync method of the chart view. Calling this method shows a loader over the chart view until the saving completes. The method returns a promise, which you can use to get notified when the saving completes.

chartView.SaveToFileAsync(@"D:\Documents\MyChart.ncb").Then(
    delegate (bool success)
    {
    },
    delegate (Exception ex)
    {
    }
);

To save a chart to a stream you need to call the SaveToStream method of the chart view and pass the chart format to save to:

chartView.SaveToStream(stream, NChartFormat.NevronBinary);

To show the standard Save File dialog, use the SaveAsAsync method:

chartView.SaveAsAsync();

If you want a specific format to be selected by default, then you need to pass it as an argument:

chartView.SaveAsAsync(NChartFormat.NevronBinary);

To load the state of NOV Chart for .NET synchronously from a local file you need to call the LoadFromLocalFile method of the chart view.

chartView.LoadFromLocalFile(@"D:\Documents\MyChart.ndb");

To load a Nevron Chart asynchronously call the LoadFromFileAsync method of the chart view. Calling this method shows a loader over the chart view until the loading completes. The method returns a promise, which can be used to get notified when the loading completes.

chartView.LoadFromFileAsync(@"D:\Documents\MyChart.ncb").Then(
    delegate (bool success)
    {
    },
    delegate (Exception ex)
    {
    }
);

To load a chart from a stream call the LoadFromStream method of the chart view and pass the chart format to load:

chartView.LoadFromStream(stream, NChartFormat.NevronBinary);

The OpenFileAsync method shows an Open File dialog with all supported chart formats:

chartView.OpenFileAsync();

If you want a specific format to be selected by default, pass it as an argument:

chartView.OpenFileAsync(NChartFormat.NevronBinary);