Question

How to set the color of a UILabel object same as the pie chart slice color when sliceWasSelectedAtRecordIndex: method is called in core plot? I am filling slice with gradient color with this method.

-(CPTFill *)sliceFillForPieChart:(CPTPieChart *)pieChart recordIndex:(NSUInteger)index
{
     sectorColour=[[[CPTFill alloc]init]autorelease];//creating a sector color object
     if (index == 0) {
          //creating cptcolor 
          CPTColor *areaColor1 = [CPTColor colorWithComponentRed:0.0 
               green:0.7
                blue:1.0
               alpha:1.0];
          CPTColor *areaColor2 = [CPTColor colorWithComponentRed:0.0 
               green:0.1
                blue:0.2
               alpha:1.0];
          UIColor *color1=[UIColor colorWithRed:0.0 green:0.7 blue:1.0 alpha:1.0];
          UIColor *color2=[UIColor colorWithRed:0.0 green:0.1 blue:0.2 alpha:1.0];

          //filling with gradient color with CPTColor
          CPTGradient *areaGradientUI = [CPTGradient gradientWithBeginningColor:(CPTColor *)color1 endingColor:(CPTColor *)color2];  
          sectorColour=[CPTFill fillWithGradient:areaGradientUI];
    }
}

Answer 1

Make the CPTGradient using CPTColor objects, not UIColors.

CPTGradient *areaGradientUI = [CPTGradient gradientWithBeginningColor:areaColor1
                                                          endingColor:areaColor2];

You can set the backgroundColor of a UILabel to a single UIColor. I’m not sure how you’d do it with a gradient without making a custom subclass that draws the background gradient.