FillPie with n sections Brush Color issue

Question

When trying to use FillPie on my graphics object, if I actually draw the entire pie it all comes out as a solid color (I'm using the print-preview object)

I've tried moving objects around to pinpoint the issue, here is what I have now:

    //Each brush is made static, mostly because I wanted to make sure I wasn't mucking them up
    internal static SolidBrush Red = new SolidBrush(Color.Red);
    internal static SolidBrush Blue = new SolidBrush(Color.Blue);
    internal static SolidBrush Green = new SolidBrush(Color.Green);
    internal static SolidBrush Yellow = new SolidBrush(Color.Yellow);
    internal static SolidBrush Purple = new SolidBrush(Color.Purple);
    internal static SolidBrush Teal = new SolidBrush(Color.Teal);
    internal static SolidBrush Gold = new SolidBrush(Color.Gold);
    internal static SolidBrush Fuchsia = new SolidBrush(Color.Fuchsia);

    //Add each brush to an array for easier access
    SolidBrush[] brushes = new SolidBrush[] {
        Red,
        Blue,
        Green,
        Yellow,
        Purple,
        Teal,
        Gold,
        Fuchsia
    };

    //The outlining pen for our pie
    Pen BlackPen = new Pen(Color.Black, 10);

    private void printDocument1_PrintPage(object sender, PrintPageEventArgs e)
    {   
        //The bounding box of our Pie
        Rectangle FirstPie = new Rectangle(100, 100, 400, 400);

        //How many slices of pie?
        float maxParts = 7;

        //Get the angle for each slice
        float partSize = 360.00F / maxParts;

        for (int i = 0; i < maxParts; i++)
        {
            //Get the angles for this slice
            float AngleStart = (float)i * partSize;
            float AngleEnd = AngleStart + partSize;

            //Check that we aren't overflowing somehow (issue persists without these lines)
            if (AngleStart < 0F) AngleStart = 0F;
            if (AngleEnd > 360F) AngleEnd = 360F;

            //Figure out which brush we are using
            int brush = (int)(i % 8);

            //Output for Debug
            Console.WriteLine(AngleStart + " " + AngleEnd + " " + brush);

            //Draw the pie and overlay
            e.Graphics.FillPie(brushes[brush], FirstPie, AngleStart, AngleEnd);
            e.Graphics.DrawPie(BlackPen, FirstPie, AngleStart, AngleEnd);
        }
    }

I get a solid-color Pie with a line running from the upper right to the center (from the DrawPie):

I can verify the angles are correct by commenting out the FillPie line and only using DrawPie:

If you look at the array and extrapolate what is happening, the entire pie is being drawn by the last color-brush being used, Gold. I output the angles and which brush is being used to the console, it is properly cycling through the brush array:

and if I change the number of Pie parts to a different number the final color still gets used (with 11 parts):

And the angles / each brush index used here

What am I doing wrong here?

Answer 1

You keep growing the size of the AngleEnd value. Don't do that:

//float AngleEnd = AngleStart + partSize;
float AngleEnd = partSize;

From Graphics.FillPie Method

sweepAngle
Angle in degrees measured clockwise from the startAngle parameter to the second side of the pie section.

Also, please use

e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;

to get rid of those rough edges.