SciChart® the market leader in Fast WPF Charts, WPF 3D Charts, iOS Chart, Android Chart and JavaScript Chart Components

0 votes
657 views

Hi,

I have a very simple iOS project in XCode 13 which uses Swift. The project has a tab bar controller with two tabs. The first tab brings up a sample home screen and the second tab initializes a blank SciChart graph.

I want to eventually be able to sometimes change what data is shown on the graph (via Bluetooth), and therefore I want to run my graph code every time the tab for the graph is selected. I put all my code for SciChart inside:

override func viewWillAppear(_ animated: Bool)

and this almost works fine, but declaring

let surface = SCIChartSurface() inside of override func viewWillAppear(_ animated: Bool)

seems to be causing some sort of memory leak. Switching between tabs often causes my app to crash and XCode reports the following error message: “Terminated due to memory issue”

Is there a better way to initialize my graph to prevent this memory leak? Or is there way to flush the “surface” variable from memory when transitioning between tabs to prevent this memory issue from occurring?

My small sample project is available here which demonstrates the memory leak when switching between the home screen tab and graph tab: https://drive.google.com/file/d/1mz88R3kKvoPqSGxFzohoHGDkseSwgHPh/view?usp=sharing

Any help greatly appreciated, thanks!

0 votes
4k views

Running off of visual studio 2017. Slightly changed one of the line examples. Here is my source code.

// *************************************************************************************
// SCICHART® Copyright SciChart Ltd. 2011-2017. All rights reserved.
//
// Web: http://www.scichart.com
// Support: support@scichart.com
// Sales: sales@scichart.com
//
// LineChartExampleView.xaml.cs is part of the SCICHART® Examples. Permission is hereby granted
// to modify, create derivative works, distribute and publish any part of this source
// code whether for commercial, private or personal use.
//
// The SCICHART® examples are distributed in the hope that they will be useful, but
// without any warranty. It is provided “AS IS” without warranty of any kind, either
// expressed or implied.
// *************************************************************************************
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Globalization;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Media;
using SciChart.Charting.Model.DataSeries;
using SciChart.Charting.Visuals.RenderableSeries;
using SciChart.Data.Model;
using SciChart.Examples.ExternalDependencies.Data;
using SciChart.Charting;

namespace SciChart.Examples.Examples.CreateSimpleChart
{
public partial class LineChartExampleView : UserControl
{
public LineChartExampleView()
{
InitializeComponent();

    }

    private void LineChartExampleView_OnLoaded(object sender, RoutedEventArgs e)
    {            
        // Create a DataSeries of type X=double, Y=double
        var dataSeries = new XyDataSeries<double, double>();

        lineRenderSeries.DataSeries = dataSeries;

        var data = DataManager.Instance.GetFourierSeries(1.0, 0.1);

        // Append data to series. SciChart automatically redraws
        ThemeManager.SetTheme(this, "Chrome");
        dataSeries.Append(data.XData, data.YData);

        sciChart.ZoomExtents();
    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        Clipboard.SetImage(this.sciChart.ExportToBitmapSource());
    }
}

}

And the xaml

<UserControl.Resources>
    <ResourceDictionary>
    </ResourceDictionary>
</UserControl.Resources>

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="Auto" />
        <ColumnDefinition Width="*" />
    </Grid.ColumnDefinitions>

    <!--  The SciChartInteractionToolbar adds zoom, pan, zoom extents and rotate functionality  -->
    <!--  to the chart and is included for example purposes.  -->
    <!--  If you wish to know how to zoom and pan a chart then do a search for Zoom Pan in the Examples suite!  -->
    <Button Foreground="AntiqueWhite"  Visibility="Visible" Click="Button_Click" MinWidth="100" MinHeight="40">COPY</Button>



    <!--  Create the chart surface  -->
    <s:SciChartSurface Name="sciChart"
                       Grid.Column="1">

        <!--  Declare RenderableSeries  -->
        <s:SciChartSurface.RenderableSeries>
            <s:FastLineRenderableSeries x:Name="lineRenderSeries"
                                        Stroke="#FF99EE99"
                                        StrokeThickness="2"/>
        </s:SciChartSurface.RenderableSeries>

        <!--  Create an X Axis with Growby  -->
        <s:SciChartSurface.XAxis>
            <s:NumericAxis DrawMajorBands="True"
                           FlipCoordinates="True"
                           GrowBy="0.1, 0.1"
                           ScientificNotation="None"
                           TextFormatting="#.############" />
        </s:SciChartSurface.XAxis>

        <!--  Create a Y Axis with Growby. Optional bands give a cool look and feel for minimal performance impact  -->
        <s:SciChartSurface.YAxis>
            <s:NumericAxis DrawMajorBands="True" GrowBy="0.5, 0.5" />
        </s:SciChartSurface.YAxis>

    </s:SciChartSurface>
</Grid>

All I did was remove the toolbar and a dd a button that copied the image to the clipboard. Yet Somehow the result of what you see while running and what you get from the clipboard are not the same. The lower half of the image you get by rendering to memory is clearly darker. I tried uploading them but could not.

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