LiveCharts Basics - How to draw a line?

Question

It’s very difficult for me to understand what should really happen with LiveCharts. Here I have a XAML block:

<Grid> <Grid.Background> <ImageBrush ImageSource="/CPF;component/Images/background-top-cropped2.png" Stretch="None"></ImageBrush> </Grid.Background> <lvc:CartesianChart Series="{Binding myData}" LegendLocation="Right" x:Name="myChart"> <lvc:CartesianChart.AxisY> <lvc:Axis Title="Sales" LabelFormatter="{Binding YFormatter}"></lvc:Axis> </lvc:CartesianChart.AxisY> <lvc:CartesianChart.AxisX> <lvc:Axis Title="Month" Labels="{Binding Labels}"></lvc:Axis> </lvc:CartesianChart.AxisX> </lvc:CartesianChart> </Grid> 

And the code behind is here:

 public MainWindow() { InitializeComponent(); DrawGraphs(); } public void DrawGraphs() { LineSeries mySeries = new LineSeries { Values = new ChartValues<int> { 12, 23, 55, 1 } }; myChart.Series.Add(mySeries); } 

At run time, 'myChart.Series.Add (mySeries)' throws a Null Reference Exception error. I'm not sure how to resolve this?

Answer 1

Since you are adding the series directly to the diagram, without using MVVM, you do not need all the bindings in XAML. You can simply do this:

XAML:

 <Window x:Class="WpfApplication1.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:lvc="clr-namespace:LiveCharts.Wpf;assembly=LiveCharts.Wpf" xmlns:local="clr-namespace:WpfApplication1" mc:Ignorable="d" Title="MainWindow" Height="350" Width="525"> <Grid> <lvc:CartesianChart x:Name="myChart" /> </Grid> 

CS:

 public partial class MainWindow : Window { public MainWindow() { InitializeComponent(); DrawGraphs(); } public void DrawGraphs() { LineSeries mySeries = new LineSeries { Values = new ChartValues<int> { 12, 23, 55, 1 } }; myChart.Series.Add(mySeries); } }