// << path-geometry-set-line-geometry
// >> path-gettingstarted-custom-geometry
internal RadPathGeometry CreateArc()
{
var geometry = new RadPathGeometry();
RadPathFigure figure = new RadPathFigure();
figure.StartPoint = new Point(0.5, 0.5);
// >> path-geometry-arc-segment
RadArcSegment segmentA = new RadArcSegment();
segmentA.Center = new Point(0.5, 0.5);
segmentA.Size = new Size(1, 1);
segmentA.StartAngle = 315;
segmentA.SweepAngle = 270;
// << path-geometry-arc-segment
figure.Segments.Add(segmentA);
RadArcSegment segmentB = new RadArcSegment();
segmentB.Center = new Point(0.5, 0.5);
segmentB.Size = new Size(1 - 0.1, 1 - 0.1);
segmentB.StartAngle = 315 + 270;
segmentB.SweepAngle = -270;
figure.Segments.Add(segmentB);
geometry.Figures.Add(figure);
return(geometry);
}
private static Grid GeneratePieChart(IList <ChartDataPoint> dataPoints, List <Color> colors, bool showLegend = true)
{
// Root container to hold the chart and any legend
var container = new Grid();
container.RowDefinitions.Add(new RowDefinition {
Height = new GridLength(3, GridUnitType.Star)
});
container.RowDefinitions.Add(new RowDefinition {
Height = new GridLength(1, GridUnitType.Star)
});
// ***** Part 1 - PIE SERIES GENERATION ***** //
// Sum up all the values to be displayed
var totalValue = dataPoints.Sum(d => d.Value);
// Variable to keep track of where each slice ended.
double currentPosition = 0;
// Iterate over the data points to create slices.
for (int i = 0; i < dataPoints.Count; i++)
{
// Determine the percentage of the whole the slice uses.
double slicePercentage = dataPoints[i].Value / totalValue;
// Calculate the sweep using that percentage
double sweep = slicePercentage * 360;
// Create the ArcSegment using the calculated values.
var segment = new RadArcSegment
{
Center = new Point(0.5, 0.5),
Size = new Size(1, 1),
StartAngle = currentPosition,
SweepAngle = sweep,
};
// Important - Calculate the last segment's ending angle in order to have a valid start angle for the next loop.
currentPosition = currentPosition + sweep - 360;
// Prepare the required PathFigure and add the ArcSegment
var figure = new RadPathFigure {
StartPoint = new Point(0.5, 0.5)
};
figure.Segments.Add(segment);
// Create the PathGeometry and add the PathFigure
var geometry = new RadPathGeometry();
geometry.Figures.Add(figure);
// Construct the RadPath
// - Select a Fill color from the brushes parameter (important: use a modulus to wrap to the beginning)
// - Use the Geometry created from the value
var slice = new RadPath
{
Fill = new RadSolidColorBrush(colors[i % colors.Count]),
Geometry = geometry,
HorizontalOptions = LayoutOptions.Center,
VerticalOptions = LayoutOptions.Center,
WidthRequest = 100,
HeightRequest = 100,
Margin = new Thickness(0, 20, 0, 0)
};
// This isn't necessary, but added for completion.
Grid.SetRow(slice, 0);
// Finally, add it to the container.
container.Children.Add(slice);
}
// ***** Part 2 - LEGEND GENERATION ***** //
if (showLegend)
{
var legendPanel = new StackLayout();
legendPanel.Orientation = StackOrientation.Horizontal;
legendPanel.HorizontalOptions = LayoutOptions.Center;
legendPanel.VerticalOptions = LayoutOptions.Center;
legendPanel.Margin = new Thickness(0, 16, 0, 0);
legendPanel.Spacing = 5;
for (int i = 0; i < dataPoints.Count; i++)
{
// Use a RadBorder with only a bottom thickness and match the color to the slice
var legendItem = new RadBorder();
legendItem.BorderColor = colors[i % colors.Count];
legendItem.BorderThickness = new Thickness(0, 0, 0, 2);
// Create a Label for each data point and use the Title property
var label = new Label
{
Text = dataPoints[i].Title,
FontSize = 12,
Margin = new Thickness(0, 0, 0, 2),
TextColor = (Color)Application.Current.Resources["LightGrayTextColor"]
};
legendItem.Content = label;
legendPanel.Children.Add(legendItem);
}
Grid.SetRow(legendPanel, 1);
container.Children.Add(legendPanel);
}
return(container);
}