CorePlot: unable to change pie chart position (displacement)

问题

I am unable to change the pie chart position (I would like it to be more left in respect to the legend so that the legend does not overlay the pie chart). Basically I would like to shift it towards the left to allow the legend to display.

I tried modifying the following properties (but with no apparent effect on the pie graph position):

   // pieChartGraph is a CPTPieChart object
   pieChartGraph.graph.position = CGPointMake(-100, 0);

   // I also tried:
   pieChart.position  = CGPointMake(-100, 0);

   // and also playing with:
   pieChart.anchorPoint

---

Here is what I get and also my code (by the way, the title does not show either):

pieChartGraph = [[CPTXYGraph alloc] initWithFrame:self.pieChartgraphHostView.bounds];
self.pieChartgraphHostView.hostedGraph = pieChartGraph;
pieChartGraph.plotAreaFrame.masksToBorder = NO;
pieChartGraph.axisSet = nil;
pieChart.title = @"title";     // <-- BTW, the title does not show either

// 2 - Create chart
pieChart = [[CPTPieChart alloc] init];
pieChart.dataSource = self;
pieChart.delegate = self;
pieChart.pieRadius = self.pieChartgraphHostView.bounds.size.width;
pieChartGraph.delegate = self;

pieChart.identifier = pieChartGraph.title;
pieChart.startAngle = CPTFloat(M_PI_4);
pieChart.sliceDirection = CPTPieDirectionClockwise;
pieChart.borderLineStyle = [CPTLineStyle lineStyle];
// 3 - Create gradient

CPTGradient *overlayGradient = [[CPTGradient alloc] init];
overlayGradient.gradientType = CPTGradientTypeRadial;
overlayGradient = [overlayGradient addColorStop:[[CPTColor blackColor] colorWithAlphaComponent:0.0] atPosition:0.9];
overlayGradient = [overlayGradient addColorStop:[[CPTColor blackColor] colorWithAlphaComponent:0.4] atPosition:1.0];
pieChart.overlayFill = [CPTFill fillWithGradient:overlayGradient];

// 4 - Add chart to graph
pieChart.pieRadius = pieChart.pieRadius / 2.3;
[pieChartGraph addPlot:pieChart];

self.dataForChart = [@[@(self.displayedLastDataPoint.percentageUnder),    @(self.displayedLastDataPoint.percentageOver), @(self.displayedLastDataPoint.percentageClean), @(self.displayedLastDataPoint.percentageRemaining)] mutableCopy];


// Add legend
CPTLegend *theLegend = [CPTLegend legendWithGraph:pieChartGraph];
theLegend.numberOfColumns = 1;
theLegend.fill            = [CPTFill fillWithColor:[CPTColor whiteColor]];
theLegend.borderLineStyle = [CPTLineStyle lineStyle];

theLegend.entryFill            = [CPTFill fillWithColor:[CPTColor lightGrayColor]];
theLegend.entryBorderLineStyle = [CPTLineStyle lineStyle];
theLegend.entryCornerRadius    = CPTFloat(3.0);
theLegend.entryPaddingLeft     = CPTFloat(3.0);
theLegend.entryPaddingTop      = CPTFloat(3.0);
theLegend.entryPaddingRight    = CPTFloat(3.0);
theLegend.entryPaddingBottom   = CPTFloat(3.0);

theLegend.cornerRadius = 5.0;
theLegend.delegate     = self;

pieChartGraph.legend = theLegend;
pieChartGraph.legendAnchor = CPTRectAnchorRight;
CGFloat legendPadding = +(self.view.bounds.size.width / 16);
pieChartGraph.legendDisplacement = CGPointMake(legendPadding, 0.0);

pieChartGraph.graph.position = CGPointMake(-30, 0);

回答1:

Set the centerAnchor to position the pie chart within the graph. It is a CGPoint. Both coordinates range between 0 and 1, similar to the anchorPoint of a CALayer.

来源：https://stackoverflow.com/questions/32224530/coreplot-unable-to-change-pie-chart-position-displacement