Develop Reference

Livecharts showing "-100000000000000 μ" instead of -100 M in a StackedColumnSeries

When a value of -1e8 is added to a StackedColumnSeries in a SKCartesianChart, the value is labelled with -100000000000000 μ instead of -100 M as expected.
I suspect this is a bug in the prerelease version of livecharts. I've reported it, but thought to ask here in case anyone's seen the same problem and has a workaround.
var chart = new SKCartesianChart
{
Series = new List<ISeries>
{
new StackedColumnSeries<decimal> {Values = new [] {1e8m}},
new StackedColumnSeries<decimal> {Values = new [] {-1e8m}}, // -100000000000000 μ
}
};

Thanks for the report on Github, this is a bug, it is already fixed, and this fix fill be included in the next version of the library.
For now, you can build your own formatter in the YAxis:
var chart = new SKCartesianChart
{
Series = new List<ISeries>
{
new StackedColumnSeries<decimal> {Values = new [] {1e8m}},
new StackedColumnSeries<decimal> {Values = new [] {-1e8m}}
},
YAxes = new[]
{
new Axis
{
Labeler = value =>
{
var l = value == 0 ? 0 : (int)Math.Log10(Math.Abs(value));
if (l >= 6)
{
value /= Math.Pow(10, 6);
return value.ToString($"######0.####### M");
}
return value.ToString($"######0.#######");
}
}
}
};

Display Linestring and Trackpoints with Mapsui

my intention is to display a gps track and the corresponding trackpoints with Mapsui (wpf) on a map. I tried the following code. The result is that the blue linestring is displayed (ok), the red track points (ok) but for any reason you see white track points which are very large and I do not want them to appear at the map and I do not know where the white dots are coming from. Any idea what I am doing wrong?
protected ILayer CreateLineStringLayer(String name, List<GeoWaypoint> geoWaypoints)
{
var lineString = new LineString();
List<Feature> featureList = new List<Feature>();
IStyle pointStyle = new SymbolStyle()
{
SymbolScale = 0.30,
Fill = new Brush(Mapsui.Styles.Color.FromString("Red"))
};
foreach (var wp in geoWaypoints)
{
var point = SphericalMercator.FromLonLat(wp.Longitude, wp.Latitude);
lineString.Vertices.Add(point);
var p2 = SphericalMercator.FromLonLat(wp.Longitude, wp.Latitude);
var pointFeature = new Feature();
pointFeature.Geometry = p2;
pointFeature.Styles.Add(pointStyle);
featureList.Add(pointFeature);
}
IStyle linestringStyle = new VectorStyle()
{
Fill = null,
Outline = null,
Line = { Color = Mapsui.Styles.Color.FromString("Blue"), Width = 4 }
};
Feature lineStringFeature = new Feature()
{
Geometry = lineString
};
lineStringFeature.Styles.Add(linestringStyle);
featureList.Add(lineStringFeature);
MemoryProvider memoryProvider = new MemoryProvider(featureList);
return new MemoryLayer
{
DataSource = memoryProvider,
Name = name
};
}

so for everyone who is interest in the answer
return new MemoryLayer
{
DataSource = memoryProvider,
Name = name ,
Style = null
};
You need to set the value for Style to null for the Memorylayer

Chartsjs (blazor) BarChart not alinged

Im not sure im doing something fairly simple wrong. Im getting below plot when using the below code. I was expecting to get the B values in its own column like you would in excel.
EDIT: I have added my config in the post also, if there are some properties that im missing
/Thomas
BarDataset<double> _barDataSet3 = new BarDataset<double>
{
Label = "A",
BackgroundColor = ColorUtil.RandomColorString(),
BorderWidth = 0,
HoverBackgroundColor = ColorUtil.RandomColorString(),
HoverBorderColor = ColorUtil.RandomColorString(),
HoverBorderWidth = 1,
BorderColor = "#ffffff"
};
_barChartConfig.Data.Labels.AddRange(new[] { "A"});
_barDataSet3.Add(2.6);
_barChartConfig.Data.Datasets.Add(_barDataSet3);
BarDataset<double> _barDataSet4 = new BarDataset<double>
{
Label = "B",
BackgroundColor = ColorUtil.RandomColorString(),
BorderWidth = 0,
HoverBackgroundColor = ColorUtil.RandomColorString(),
HoverBorderColor = ColorUtil.RandomColorString(),
HoverBorderWidth = 1,
BorderColor = "#ffffff"
};
_barChartConfig.Data.Labels.AddRange(new[] { "B" });
_barDataSet4.Add(4.5);
_barChartConfig.Data.Datasets.Add(_barDataSet4);
EDIT: My config - is there a property that im missing?:
_barChartConfig = new BarConfig
{
Options = new BarOptions
{
Title = new OptionsTitle
{
Display = true,
Text = "Simple Bar Chart"
},
Scales = new BarScales
{
XAxes = new List<CartesianAxis>
{
new BarCategoryAxis
{
BarPercentage = 0.5,
BarThickness = BarThickness.Flex
}
},
YAxes = new List<CartesianAxis>
{
new BarLinearCartesianAxis
{
Ticks = new LinearCartesianTicks
{
BeginAtZero = true
}
}
}
}
}
};

How do I wait for a handle to be created for a comboBox, so that I can change the selectedIndex?

I'm stuck on this problem with a ComboBox.
I need to create it programmatically, set a DataSource, add it to my form and then change the SelectedIndex. I'm doing it like this:
rectangle = new Rectangle(x, y, width, height)
ComboBox cb = new ComboBox
{
Size = Rectangle.Size,
Location = Rectangle.Location,
DataSource = new List<string>(comboBoxDataSource),
};
Form1.Controls.Add(cb);
cb.SelectedIndex = index;
When the program gets to that last line, i throws an error saying:
System.ArgumentOutOfRangeException: 'InvalidArgument=Value of '4' is
not valid for 'SelectedIndex'. Parameter name: SelectedIndex'
When the code crash I can see that the ComboBox contains 6 items, so shouldn't index '4' be valid at this point?
I have read some articles and other questions about the problem, but nothing I have found have worked. I think it's because the form doesn't create a handle for the ComboBox, before I try to change the index.
Is there anyone who have had a similar problem, or know a solution?

Bind the datasource after you add your combobox to the control. Then you can select an item.
var dataSource = new List<string> { "one", "two", "three", "four", "five" };
var rectangle = new Rectangle(10, 10, 100, 40);
ComboBox cb = new ComboBox
{
Location = rectangle.Location,
Size = rectangle.Size,
};
this.Controls.Add(cb);
cb.DataSource = new List<string>(dataSource);
cb.SelectedIndex = 3;

Add a BindingSource and set its DataSource. Add a binding context to the combobox and after that set the combobox DataSource to the BindingSource.DataSource. See below:
string[] dataSource = new string[30];
for (int i = 0; i < 30; i++) {
dataSource[i] = "test " + i.ToString();
}
ComboBox cb = new ComboBox();
cb.Size = new Size(121, 21);
cb.Location = new Point(55, 74);
BindingSource bS = new BindingSource();
cb.BindingContext = new BindingContext();
bS.DataSource = dataSource;
cb.DataSource = bS.DataSource;
cb.SelectedIndex = 4; // shoul and does display test 3
this.Controls.Add(cb);

Oxyplot column series - Add items by using a loop

I have a oxyplot column series which I have masked as a histogram using a linear axis. I get my values from a list called frequency with 20 elements.
I wonder if there is a smarter way to do this:
this.Items = new Collection<Item>
{
new Item {Label = "1", Value=frequency[0]},
new Item {Label = "2", Value=frequency[1]},
new Item {Label = "3", Value=frequency[2]},
...
new Item {Label = "18", Value=frequency[17]},
new Item {Label = "19", Value=frequency[18]},
new Item {Label = "20", Value=frequency[19]},
};
I have tried to create a for-loop inside like this:
this.Items = new Collection<Item>
{
for (int i = 0; i < 20; i++)
{
Items.Add(new Item { Label = i.ToString(), Value = frequency[i]});
}
};
But it does not work.
Does anyone have an idea on how to do this?

You can't put the for loop in the object initializer.
Create the collection.
this.Items = new Collection<Item>();
Populate it:
for (int i = 0; i< 20; i++)
{
Items.Add(new Item { Label = i.ToString(), Value = frequency[i] });
}