How to draw shapes and color them with a button? [closed]

Answer 1

It wasn't quite as hard as I thought, but I did simplyfy the task by creating not a 'C' but a half circle. To create a 'C' shape you need to break the shapes into three groups: Two quarter circles and a rectangle.. Add all Shapes to the same list!

The processing will be the same, just the math part will differ. Actually the math for the rectangle part will be even a little more involved than the extremely simple way it works for arcs :-)

Here is an example of a very simple Shape class:

class Shape
{
    public GraphicsPath Path { get; set; }
    public Color FillColor { get; set; }

    public Shape(GraphicsPath gp) { Path = gp; }
}

You can create a List<Shape> for it like this:

List<Shape> FillList(int segments, int angle1, int angle2, int inner, int outer, int rings)
{
    List<Shape> paths = new List<Shape>();
    float deltaA = 1f * (angle2 - angle1) / segments;
    float width = 1f * (outer - inner ) / rings;
    for (int s = 0; s < segments; s++)
    {
        float a = angle1 + s * deltaA;
        for (int r = 0; r < rings; r++)
        {
            float w1 = r * width;
            float w2 = w1 + width;
            GraphicsPath gp = new GraphicsPath();

            RectangleF rect1 = new RectangleF(w1, w1, (outer - w1) * 2,  (outer - w1) * 2);
            RectangleF rect2 = new RectangleF(w2, w2, (outer - w2) * 2,  (outer - w2) * 2);
            gp.AddArc(rect1, a, deltaA);
            gp.AddArc(rect2, a + deltaA, -deltaA);
            gp.CloseFigure();
            paths.Add(new Shape(gp));
        }
    }
    return paths;
}

I have added a few NumericUpDowns to demonstrate the parameters at work:

As you can see I color the Shapes by selecting one and then picking a color from a palette image..

Here is the Form's Paint event:

private void Form1_Paint(object sender, PaintEventArgs e)
{
    foreach (Shape gp in paths)
    {
        using (SolidBrush br = new SolidBrush(gp.FillColor))
            if (gp.FillColor != null) e.Graphics.FillPath(br, gp.Path);
        e.Graphics.DrawPath(Pens.Black, gp.Path);
        if (gp == selected) e.Graphics.DrawPath(Pens.OrangeRed, gp.Path);
    }

}

The shapes are filled with their Color if they have one and also drawn at some color; I use a fixed black Pen for this and a red one for the Selected shape if there is one..

The whole selection and coloring is as simple as this:

Shape selected = null;

private void pictureBox1_MouseClick(object sender, MouseEventArgs e)
{
    if (selected != null)
    {
        selected.FillColor = ((Bitmap)pictureBox1.Image).GetPixel(e.X, e.Y);
        Invalidate();
    }
}

private void Form1_MouseClick(object sender, MouseEventArgs e)
{
    selected = null;
    foreach (Shape gp in paths)
        if (gp.Path.IsVisible(e.Location)) { selected = gp; break; }
    Invalidate();
}