How to draw an arc from radius and inner angle in Silverlight

Question

In a silverlight 3 project I have to draw an arc programatically and I have radius of circle and inner angle of the arc. Could you please direct me to some related articles.

Thanks in anticipation!

Haris

Answer 1

This seems to be a good article on building arcs dynamically http://codingbandit.com/Blog/blog/dynamically-creating-path-data-in-silverlight-2/

To calculate the points the following formula is used.

x = a + r * cos(θ)
y = b + r * sin(θ)

* r is the radius of the circle
* (a,b) is the center of the circle
* (x,y) is the point on the circumference
* θ is the angle in degrees
* radian = degree * π/180

you have the radius of the circle r and also the angle θ. That should build up the point series.

Answer 2

You're going to want to look at Paths in silverlight and specifically at the ArcSegments section.

ArcSegment Documentation

MSDN Path Geometry Samples

Answer 3

With Expression Blend 4. You could use Arc.

Example:

<UserControl
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:ed="http://schemas.microsoft.com/expression/2010/drawing"
    x:Class="SilverlightApplication1.MainPage"
    Width="640" Height="480">

    <Grid x:Name="LayoutRoot" Background="White">
        <Canvas Margin="101,88,118,125">
            <ed:Arc ArcThickness="0" ArcThicknessUnit="Pixel" EndAngle="90" Fill="#FFF4F4F5" Height="60" Canvas.Left="101" Stretch="None" Stroke="Black" StartAngle="0" Canvas.Top="63" UseLayoutRounding="False" Width="57"/>
        </Canvas>
    </Grid>
</UserControl>