向 CorePlot 切片添加图例
Adding legend to CorePlot slice
我希望能够为图表切片添加图例。我该怎么做？
我尝试实现了以下两种方法，但我认为不对；
- (NSString *) legendTitleForPieChart:(CPTPieChart *)pieChart
recordIndex:(NSUInteger)idx{
return @"Legend";
}
- (NSAttributedString *) attributedLegendTitleForPieChart: (CPTPieChart *) pieChart
recordIndex: (NSUInteger) idxv{
return [[NSAttributedString alloc] initWithString:@"Attributed"];
}
这里是官方的 CorePlot 协议文档：
编辑：我的代码
// .h
@interface MyViewController : UIViewController<CPTPlotSpaceDelegate,CPTPieChartDelegate,CPTLegendDelegate,CPTPlotDataSource>
- (void) initializeAll;
- (id) initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil data:(NSMutableArray*)dataPoints;
// .m
#import “MyViewController.h"
#import <QuartzCore/QuartzCore.h>
@interface MyViewController ()
@property (weak, nonatomic) IBOutlet CPTGraphHostingView * pieChartgraphHostView;
@property (strong, nonatomic) CPTGraph* pieChartGraph;
@property (strong, nonatomic) CPTPieChart* pieChart;
@end
@implementation MyViewController
@synthesize data;
@synthesize pieChart, pieChartGraph;
- (id) initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil data:(NSMutableArray*)dataPoints{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
self.data = dataPoints;
}
return self;
}
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
[self initializeGraph];
[self updateViewData];
[self configureChart];
}
- (void) initializeGraph{
if (self.data == nil) {
NSLog(@"Error, should not use this without assigning data");
}
// Create a CPTGraph object and add to hostView
self.graph = [[CPTXYGraph alloc] initWithFrame:self.graphHostView.bounds];
self.graphHostView.hostedGraph = self.graph;
////////////////////
CPTMutableTextStyle *titleStyle = [CPTMutableTextStyle textStyle];
titleStyle.color = [CPTColor blackColor];
titleStyle.fontName = @"Helvetica";
titleStyle.fontSize = 12.0f;
// Axes
// Label x axis with a fixed interval policy
CPTXYAxisSet *axisSet = (CPTXYAxisSet *)self.graph.axisSet;
CPTXYAxis *x = axisSet.xAxis;
x.separateLayers = NO;
x.title = @"X Axis";
x.titleTextStyle = titleStyle;
x.delegate = self;
CPTXYAxis *y = axisSet.yAxis;
y.labelingPolicy = CPTAxisLabelingPolicyAutomatic;
y.separateLayers = YES;
y.majorTickLocations = [NSSet setWithObjects:
[NSDecimalNumber numberWithDouble:0],
[NSDecimalNumber numberWithDouble:300],
nil];
y.title = @"Y Axis";
y.titleTextStyle = titleStyle;
y.delegate = self;
CPTFill *whitebandFill = [CPTFill fillWithColor:[[CPTColor whiteColor] colorWithAlphaComponent:0.5]];
CPTFill *greenbandFill = [CPTFill fillWithColor:[[CPTColor greenColor] colorWithAlphaComponent:0.5]];
CPTFill *redbandFill = [CPTFill fillWithColor:[[CPTColor redColor] colorWithAlphaComponent:0.75]];
[y addBackgroundLimitBand:[CPTLimitBand limitBandWithRange:[CPTPlotRange plotRangeWithLocationDecimal:CPTDecimalFromDouble(0.0) lengthDecimal:CPTDecimalFromDouble(500.0)] fill:whitebandFill]];
[y addBackgroundLimitBand:[CPTLimitBand limitBandWithRange:[CPTPlotRange plotRangeWithLocationDecimal:CPTDecimalFromDouble(500.0) lengthDecimal:CPTDecimalFromDouble(750.0)] fill:greenbandFill]];
[y addBackgroundLimitBand:[CPTLimitBand limitBandWithRange:[CPTPlotRange plotRangeWithLocationDecimal:CPTDecimalFromDouble(750.0) lengthDecimal:CPTDecimalFromDouble(1024.0)] fill:redbandFill]];
// Add the y2 axis to the axis set
self.graph.axisSet.axes = @[x, y];
/////////////////////
// Get the (default) plotspace from the graph so we can set its x/y ranges
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *) self.graph.defaultPlotSpace;
// Note that these CPTPlotRange are defined by START and LENGTH (not START and END) !!
[plotSpace setYRange: [CPTPlotRange plotRangeWithLocation:[NSNumber numberWithInt:0] length:[NSNumber numberWithInt:1024]]];
NSLog(@"creating x range for %lu data points", (unsigned long)[self.data count]);
[plotSpace setXRange: [CPTPlotRange plotRangeWithLocation:[NSNumber numberWithInt:0] length:[NSNumber numberWithInt:[self.data count]]]];
// Create the plot (we do not define actual x/y values yet, these will be supplied by the datasource...)
self.plot = [[CPTScatterPlot alloc] initWithFrame:CGRectZero];
// Let's keep it simple and let this class act as datasource (therefore we implemtn <CPTPlotDataSource>)
self.plot.dataSource = self;
self.plot.delegate = self;
// Finally, add the created plot to the default plot space of the CPTGraph object we created before
[self.graph addPlot:self.plot toPlotSpace:self.graph.defaultPlotSpace];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(void)configureChart {
// 1 - Get reference to graph
pieChartGraph = [[CPTXYGraph alloc] initWithFrame:self.pieChartgraphHostView.bounds];
self.pieChartgraphHostView.hostedGraph = pieChartGraph;
pieChartGraph.plotAreaFrame.masksToBorder = NO;
pieChartGraph.axisSet = nil;
pieChart.title = @"My pie chart";
// 2 - Create chart
pieChart = [[CPTPieChart alloc] init];
pieChart.dataSource = self;
pieChart.delegate = self;
pieChart.pieRadius = (self.pieChartgraphHostView.bounds.size.height * 0.9) / 2;
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 = [@[@20.0, @30.0, @25.0, @25.0] mutableCopy];
}
-(void)setRoundedView:(UIView *)roundedView toDiameter:(float)newSize;
{
CGPoint saveCenter = roundedView.center;
CGRect newFrame = CGRectMake(roundedView.frame.origin.x, roundedView.frame.origin.y, newSize, newSize);
roundedView.frame = newFrame;
roundedView.layer.cornerRadius = newSize / 2.0;
roundedView.center = saveCenter;
}
-(void)configureLegend {
// 1 - Get graph instance
CPTGraph *graph = self.graphHostView.hostedGraph;
// 2 - Create legend
CPTLegend *theLegend = [CPTLegend legendWithGraph:graph];
// 3 - Configure legen
theLegend.numberOfColumns = 1;
theLegend.fill = [CPTFill fillWithColor:[CPTColor whiteColor]];
theLegend.borderLineStyle = [CPTLineStyle lineStyle];
theLegend.cornerRadius = 5.0;
// 4 - Add legend to graph
graph.legend = theLegend;
graph.legendAnchor = CPTRectAnchorRight;
CGFloat legendPadding = -(self.view.bounds.size.width / 8);
graph.legendDisplacement = CGPointMake(legendPadding, 0.0);
}
/*
#pragma mark - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
// Get the new view controller using [segue destinationViewController].
// Pass the selected object to the new view controller.
}
*/
#pragma mark -
#pragma mark Plot Data Source Methods
- (NSString *) legendTitleForPieChart:(CPTPieChart *)pieChart
recordIndex:(NSUInteger)idx{
return @"Legend";
}
/**
- (NSAttributedString *) attributedLegendTitleForPieChart: (CPTPieChart *) pieChart
recordIndex: (NSUInteger) idxv{
return [[NSAttributedString alloc] initWithString:@"Attributed"];
}**/
-(NSAttributedString *)attributedLegendTitleForPieChart:(CPTPieChart *)pieChart recordIndex:(NSUInteger)index
{
#if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE
UIColor *sliceColor = [CPTPieChart defaultPieSliceColorForIndex:index].uiColor;
UIFont *labelFont = [UIFont fontWithName:@"Helvetica" size:12.0 * CPTFloat(0.5)];
#else
NSColor *sliceColor = [CPTPieChart defaultPieSliceColorForIndex:index].nsColor;
NSFont *labelFont = [NSFont fontWithName:@"Helvetica" size:12.0 * CPTFloat(0.5)];
#endif
NSMutableAttributedString *title = [[NSMutableAttributedString alloc] initWithString:[NSString stringWithFormat:@"Pie Slice %lu", (unsigned long)index]];
[title addAttribute:NSForegroundColorAttributeName
value:sliceColor
range:NSMakeRange(4, 5)];
[title addAttribute:NSFontAttributeName
value:labelFont
range:NSMakeRange(0, title.length)];
return title;
}
@end
标题、图例和标签不会显示。
您只需要其中一种方法。如果您需要像示例图像中那样的样式文本，请使用属性标题，否则任何一种方法都可以使用。这些方法应该在绘图的数据源中实现。
我希望能够为图表切片添加图例。我该怎么做？
我尝试实现了以下两种方法，但我认为不对；
- (NSString *) legendTitleForPieChart:(CPTPieChart *)pieChart
recordIndex:(NSUInteger)idx{
return @"Legend";
}
- (NSAttributedString *) attributedLegendTitleForPieChart: (CPTPieChart *) pieChart
recordIndex: (NSUInteger) idxv{
return [[NSAttributedString alloc] initWithString:@"Attributed"];
}
这里是官方的 CorePlot 协议文档：
编辑：我的代码
// .h
@interface MyViewController : UIViewController<CPTPlotSpaceDelegate,CPTPieChartDelegate,CPTLegendDelegate,CPTPlotDataSource>
- (void) initializeAll;
- (id) initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil data:(NSMutableArray*)dataPoints;
// .m
#import “MyViewController.h"
#import <QuartzCore/QuartzCore.h>
@interface MyViewController ()
@property (weak, nonatomic) IBOutlet CPTGraphHostingView * pieChartgraphHostView;
@property (strong, nonatomic) CPTGraph* pieChartGraph;
@property (strong, nonatomic) CPTPieChart* pieChart;
@end
@implementation MyViewController
@synthesize data;
@synthesize pieChart, pieChartGraph;
- (id) initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil data:(NSMutableArray*)dataPoints{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
self.data = dataPoints;
}
return self;
}
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
[self initializeGraph];
[self updateViewData];
[self configureChart];
}
- (void) initializeGraph{
if (self.data == nil) {
NSLog(@"Error, should not use this without assigning data");
}
// Create a CPTGraph object and add to hostView
self.graph = [[CPTXYGraph alloc] initWithFrame:self.graphHostView.bounds];
self.graphHostView.hostedGraph = self.graph;
////////////////////
CPTMutableTextStyle *titleStyle = [CPTMutableTextStyle textStyle];
titleStyle.color = [CPTColor blackColor];
titleStyle.fontName = @"Helvetica";
titleStyle.fontSize = 12.0f;
// Axes
// Label x axis with a fixed interval policy
CPTXYAxisSet *axisSet = (CPTXYAxisSet *)self.graph.axisSet;
CPTXYAxis *x = axisSet.xAxis;
x.separateLayers = NO;
x.title = @"X Axis";
x.titleTextStyle = titleStyle;
x.delegate = self;
CPTXYAxis *y = axisSet.yAxis;
y.labelingPolicy = CPTAxisLabelingPolicyAutomatic;
y.separateLayers = YES;
y.majorTickLocations = [NSSet setWithObjects:
[NSDecimalNumber numberWithDouble:0],
[NSDecimalNumber numberWithDouble:300],
nil];
y.title = @"Y Axis";
y.titleTextStyle = titleStyle;
y.delegate = self;
CPTFill *whitebandFill = [CPTFill fillWithColor:[[CPTColor whiteColor] colorWithAlphaComponent:0.5]];
CPTFill *greenbandFill = [CPTFill fillWithColor:[[CPTColor greenColor] colorWithAlphaComponent:0.5]];
CPTFill *redbandFill = [CPTFill fillWithColor:[[CPTColor redColor] colorWithAlphaComponent:0.75]];
[y addBackgroundLimitBand:[CPTLimitBand limitBandWithRange:[CPTPlotRange plotRangeWithLocationDecimal:CPTDecimalFromDouble(0.0) lengthDecimal:CPTDecimalFromDouble(500.0)] fill:whitebandFill]];
[y addBackgroundLimitBand:[CPTLimitBand limitBandWithRange:[CPTPlotRange plotRangeWithLocationDecimal:CPTDecimalFromDouble(500.0) lengthDecimal:CPTDecimalFromDouble(750.0)] fill:greenbandFill]];
[y addBackgroundLimitBand:[CPTLimitBand limitBandWithRange:[CPTPlotRange plotRangeWithLocationDecimal:CPTDecimalFromDouble(750.0) lengthDecimal:CPTDecimalFromDouble(1024.0)] fill:redbandFill]];
// Add the y2 axis to the axis set
self.graph.axisSet.axes = @[x, y];
/////////////////////
// Get the (default) plotspace from the graph so we can set its x/y ranges
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *) self.graph.defaultPlotSpace;
// Note that these CPTPlotRange are defined by START and LENGTH (not START and END) !!
[plotSpace setYRange: [CPTPlotRange plotRangeWithLocation:[NSNumber numberWithInt:0] length:[NSNumber numberWithInt:1024]]];
NSLog(@"creating x range for %lu data points", (unsigned long)[self.data count]);
[plotSpace setXRange: [CPTPlotRange plotRangeWithLocation:[NSNumber numberWithInt:0] length:[NSNumber numberWithInt:[self.data count]]]];
// Create the plot (we do not define actual x/y values yet, these will be supplied by the datasource...)
self.plot = [[CPTScatterPlot alloc] initWithFrame:CGRectZero];
// Let's keep it simple and let this class act as datasource (therefore we implemtn <CPTPlotDataSource>)
self.plot.dataSource = self;
self.plot.delegate = self;
// Finally, add the created plot to the default plot space of the CPTGraph object we created before
[self.graph addPlot:self.plot toPlotSpace:self.graph.defaultPlotSpace];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(void)configureChart {
// 1 - Get reference to graph
pieChartGraph = [[CPTXYGraph alloc] initWithFrame:self.pieChartgraphHostView.bounds];
self.pieChartgraphHostView.hostedGraph = pieChartGraph;
pieChartGraph.plotAreaFrame.masksToBorder = NO;
pieChartGraph.axisSet = nil;
pieChart.title = @"My pie chart";
// 2 - Create chart
pieChart = [[CPTPieChart alloc] init];
pieChart.dataSource = self;
pieChart.delegate = self;
pieChart.pieRadius = (self.pieChartgraphHostView.bounds.size.height * 0.9) / 2;
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 = [@[@20.0, @30.0, @25.0, @25.0] mutableCopy];
}
-(void)setRoundedView:(UIView *)roundedView toDiameter:(float)newSize;
{
CGPoint saveCenter = roundedView.center;
CGRect newFrame = CGRectMake(roundedView.frame.origin.x, roundedView.frame.origin.y, newSize, newSize);
roundedView.frame = newFrame;
roundedView.layer.cornerRadius = newSize / 2.0;
roundedView.center = saveCenter;
}
-(void)configureLegend {
// 1 - Get graph instance
CPTGraph *graph = self.graphHostView.hostedGraph;
// 2 - Create legend
CPTLegend *theLegend = [CPTLegend legendWithGraph:graph];
// 3 - Configure legen
theLegend.numberOfColumns = 1;
theLegend.fill = [CPTFill fillWithColor:[CPTColor whiteColor]];
theLegend.borderLineStyle = [CPTLineStyle lineStyle];
theLegend.cornerRadius = 5.0;
// 4 - Add legend to graph
graph.legend = theLegend;
graph.legendAnchor = CPTRectAnchorRight;
CGFloat legendPadding = -(self.view.bounds.size.width / 8);
graph.legendDisplacement = CGPointMake(legendPadding, 0.0);
}
/*
#pragma mark - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
// Get the new view controller using [segue destinationViewController].
// Pass the selected object to the new view controller.
}
*/
#pragma mark -
#pragma mark Plot Data Source Methods
- (NSString *) legendTitleForPieChart:(CPTPieChart *)pieChart
recordIndex:(NSUInteger)idx{
return @"Legend";
}
/**
- (NSAttributedString *) attributedLegendTitleForPieChart: (CPTPieChart *) pieChart
recordIndex: (NSUInteger) idxv{
return [[NSAttributedString alloc] initWithString:@"Attributed"];
}**/
-(NSAttributedString *)attributedLegendTitleForPieChart:(CPTPieChart *)pieChart recordIndex:(NSUInteger)index
{
#if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE
UIColor *sliceColor = [CPTPieChart defaultPieSliceColorForIndex:index].uiColor;
UIFont *labelFont = [UIFont fontWithName:@"Helvetica" size:12.0 * CPTFloat(0.5)];
#else
NSColor *sliceColor = [CPTPieChart defaultPieSliceColorForIndex:index].nsColor;
NSFont *labelFont = [NSFont fontWithName:@"Helvetica" size:12.0 * CPTFloat(0.5)];
#endif
NSMutableAttributedString *title = [[NSMutableAttributedString alloc] initWithString:[NSString stringWithFormat:@"Pie Slice %lu", (unsigned long)index]];
[title addAttribute:NSForegroundColorAttributeName
value:sliceColor
range:NSMakeRange(4, 5)];
[title addAttribute:NSFontAttributeName
value:labelFont
range:NSMakeRange(0, title.length)];
return title;
}
@end
标题、图例和标签不会显示。
您只需要其中一种方法。如果您需要像示例图像中那样的样式文本，请使用属性标题，否则任何一种方法都可以使用。这些方法应该在绘图的数据源中实现。