Question

I am a beginner in iPhone programing. I need to create circles like Figure 1, where it should be divided in six different parts with four different levels (see Figure 1). Furthermore I need to create a circle according to a given data as it is shown on Figure 2. Each part should be click-able to zoom the specific part (see Figure 3).

Figure 1: Illustrates six different colors, where two of them are divided in one and the rest four of them are divided in three parts.


Figure 2: Shows the results of different categories in different levels.


Figure 3: Is a zoomed vision of chosen category.

I have a storyboard which loads loads a custom UIView and using drawRect method to draw the circle.

The question is now, how to create the pie chart like the figures?

I have tried lots of things and could use some guideness – or please give an example of this.
Thanks

Answer 1

Pie Chart Example:

int sum = 0;
CGFloat offset;
CGFloat angleArray[numberOfSections+1];

CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetAllowsAntialiasing(context, true);
CGContextSetShouldAntialias(context, true);

for(int i=0; i<numberOfSections; i++) {
    sum += angle;
}

for(int i=0; i<numberOfSections; i++) {
    angleArray[i] = (float)((angle)/(float)sum)*(2*M_PI); 
    CGContextMoveToPoint(context, radius, radius);

    if(i == 0) {
        CGContextAddArc(context, radius, radius, radius, 0, angleArray[i], 0);
    } else {
        CGContextAddArc(context, radius, radius, radius, offset, (offset+angleArray[i]), 0);
    }
    offset += angleArray[i];

    CGContextSetFillColorWithColor(context, ((UIColor *)[hjulColorArray objectAtIndex:i]).CGColor);
    CGContextClosePath(context); 
    CGContextFillPath(context);
}