Question

I want to draw a pie chart with some thickness. I have generated simple 2D pie chart. is there any way to make it 3D using some concepts of CALayer and then rotating in some direction.

-(void)CreatePieChart
{

  graph = [[CPXYGraph alloc] initWithFrame: CGRectZero];    
  //CPGraphHostingView *hostingView = (CPGraphHostingView *)self.view;
  viewGraphHostingPie.hostedGraph=graph;

  CPPieChart *pieChart = [[CPPieChart alloc] init];
  pieChart.dataSource = self;
  pieChart.delegate = self;
  pieChart.pieRadius = 100.0;
  pieChart.identifier = @"PieChart1";
  pieChart.startAngle=0;

  pieChart.sliceDirection = CPPieDirectionCounterClockwise;

  NSMutableArray *ValueArray = [[NSMutableArray alloc]init];
  ValueArray = [NSArray arrayWithObjects:[NSNumber numberWithDouble:57.03],[NSNumber numberWithDouble:66.00],[NSNumber numberWithDouble:77.03],nil];
  self.pieData = ValueArray;

  CPTheme *theme = [CPTheme themeNamed:kCPDarkGradientTheme];
  [graph applyTheme:theme];

  [graph addPlot:pieChart];
  [pieChart release];

}

Answer 1

It’s not clear to me what you mean by “concepts of CALayer”.

Have you considered using a free third party solution which will give you various charts, including pie charts, out of the box? Core Plot is free.

EDIT: Core Plot is 2D only, but you can produce a 3D effect by using shadows and/or overlay fill. See also the accepted answer here.