更改Core Plot饼图标题的外观

我想在我使用Core Plot生成的饼图中使用纯黑色背景。 我有很好的图表渲染，但标题是默认的blackColor，很难在黑色背景上看到。 我知道它正在显示，因为当我改变主题时，我可以看到它是黑色的。 谁能像我对数据标签一样告诉我如何更改文本颜色？

这是我的代码片段……

graph = [[CPTXYGraph alloc] initWithFrame:self.view.bounds]; CPTGraphHostingView *hostingView = (CPTGraphHostingView*)self.view; hostingView.hostedGraph = graph; CPTPieChart *pieChart = [[CPTPieChart alloc] init]; pieChart.dataSource = self; pieChart.pieRadius = 80.0; pieChart.identifier = @"PieChart1"; pieChart.startAngle = M_PI_4; pieChart.sliceDirection = CPTPieDirectionCounterClockwise; [graph addPlot:pieChart]; graph.title = @"Proportion of Sessions per Sport"; } -(CPTLayer *)dataLabelForPlot:(CPTPlot *)plot recordIndex:(NSUInteger)index { static CPTMutableTextStyle *whiteText = nil; if (!whiteText) { whiteText = [[CPTMutableTextStyle alloc] init]; whiteText.color = [CPTColor whiteColor]; } CPTLayer *layer = [[CPTLayer alloc] initWithFrame:CGRectMake(50, 50, 100, 20)]; CPTTextLayer *newLayer = nil; newLayer = [[CPTTextLayer alloc] initWithText:[NSString stringWithFormat:@"%@", [pieLabels objectAtIndex:index]] style:whiteText]; [layer addSublayer:newLayer]; return newLayer; } -(NSUInteger)numberOfRecordsForPlot:(CPTPlot *)plot { return [self.pieData count]; } -(NSNumber *)numberForPlot:(CPTPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index { return [self.pieData objectAtIndex:index]; } -(NSString *)legendTitleForPieChart:(CPTPieChart *)pieChart recordIndex:(NSUInteger)index { return [NSString stringWithFormat:@"Pie Slice %u", index]; } 

非常感谢您提供的任何帮助/建议/链接……

Answer 1

我在Core Plot示例代码中找到了一直盯着我的答案……

对于任何绊倒这个问题的人来说，答案是：

 CPTMutableTextStyle *whiteText = [CPTMutableTextStyle textStyle]; whiteText.color = [CPTColor whiteColor]; graph.titleTextStyle = whiteText; graph.title = @"Your Title Here...";