尽管花费了无数个小时检查代码行，并且在创建了一个功能齐全的散点图之后，我还是无法让条形图显示在我的条形图上。
我正在使用 Core Plot，我确信我已经导入了 core plot 库并正确设置了 core plot 环境，因为散点图完全正常工作。
有人可以帮我拔掉头发，也许可以告诉我哪里出错了？我有一种感觉，因为我的 #define BAR_POSITION @"POSITION" 和 #define BAR_HEIGHT @"HEIGHT" 没有正确设置/调用。
下面是我用于头文件和主文件的代码。
任何和所有的帮助表示赞赏。
头文件：
#import <UIKit/UIKit.h>
#import "CorePlot-CocoaTouch.h"
@interface BarPlotViewController : UIViewController
<CPTBarPlotDataSource, CPTBarPlotDelegate> {
}
@property (nonatomic, retain) NSMutableArray *data;
@property (nonatomic, retain) CPTGraphHostingView *hostingView;
@property (nonatomic, retain) CPTXYGraph *graph;
- (void) generateBarPlot;
@end
主文件：
#import "BarPlotViewController.h"
@implementation BarPlotViewController
#define BAR_POSITION @"POSITION"
#define BAR_HEIGHT @"HEIGHT"
#define COLOR @"COLOR"
#define CATEGORY @"CATEGORY"
#define AXIS_START 0
#define AXIS_END 50
@synthesize data;
@synthesize graph;
@synthesize hostingView;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
self.data = [NSMutableArray array];
int bar_heights[] = {20,30,10,40};
NSLog(@"After heights initialised.");
int bar_positions[] = {10,20,30,40};
NSLog(@"After position initialised.");
UIColor *colors[] = {
[UIColor redColor],
[UIColor blueColor],
[UIColor orangeColor],
[UIColor purpleColor]};
NSLog(@"After colors initialised.");
NSString *categories[] = {@"A", @"B", @"C", @"D"};
NSLog(@"After categories initialised.");
for (int i = 0; i < 4 ; i++){
double position = i*10; //Bars will be 10 pts away from each other
double height = bar_heights[i];
//double position = bar_positions[i];
NSDictionary *bar = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithDouble:position],BAR_POSITION,
[NSNumber numberWithDouble:height],BAR_HEIGHT,
colors[i],COLOR,
categories[i],CATEGORY,
nil];
[self.data addObject:bar];
NSLog(@"Data entered into bar dictionary.");
//NSString *positionStringValue = [NSString stringWithFormat:@"%.02f", position];
//NSString *log = [@"Position " stringByAppendingFormat: positionStringValue];
//NSLog( log );
//NSString *colorsStringValue = [NSString stringWithFormat:@"%.02f", position];
//NSString *log2 = [@"Colors " stringByAppendingFormat: colors[i]];
//NSLog( log2 );
}
[self generateBarPlot];
NSLog(@"After generate bar plot.");
}
return self;
}
- (void)generateBarPlot
{
//Create host view
self.hostingView = [[CPTGraphHostingView alloc]
initWithFrame:[[UIScreen mainScreen]bounds]];
[self.view addSubview:self.hostingView];
//Create graph and set it as host view's graph
self.graph = [[CPTXYGraph alloc] initWithFrame:self.hostingView.bounds];
//self.graph = [[CPTXYGraph alloc] initWithHostingView:_graphHostingView];
[self.hostingView setHostedGraph:self.graph];
//self.scatterPlot = [[TUTSimpleScatterPlot alloc] initWithHostingView:_graphHostingView andData:data];
//[self.scatterPlot initialisePlot];
//set graph padding and theme
self.graph.plotAreaFrame.paddingTop = 20.0f;
self.graph.plotAreaFrame.paddingRight = 20.0f;
self.graph.plotAreaFrame.paddingBottom = 70.0f;
self.graph.plotAreaFrame.paddingLeft = 70.0f;
[self.graph applyTheme:[CPTTheme themeNamed:kCPTDarkGradientTheme]];
// Gets rid of decimal on years
NSNumberFormatter *labelFormatter = [[NSNumberFormatter alloc] init];
labelFormatter.maximumFractionDigits = 0;
//set axes ranges
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)self.graph.defaultPlotSpace;
plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:
CPTDecimalFromFloat(AXIS_START)
length:CPTDecimalFromFloat((AXIS_END - AXIS_START))];
plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:
CPTDecimalFromFloat(AXIS_START)
length:CPTDecimalFromFloat((AXIS_END - AXIS_START))];
CPTXYAxisSet *axisSet = (CPTXYAxisSet *)self.graph.axisSet;
//set axes' title, labels and their text styles
CPTMutableTextStyle *textStyle = [CPTMutableTextStyle textStyle];
textStyle.fontName = @"Helvetica";
textStyle.fontSize = 14;
textStyle.color = [CPTColor whiteColor];
axisSet.xAxis.title = @"A";
axisSet.yAxis.title = @"B";
axisSet.xAxis.titleTextStyle = textStyle;
axisSet.yAxis.titleTextStyle = textStyle;
axisSet.xAxis.titleOffset = 30.0f;
axisSet.yAxis.titleOffset = 40.0f;
axisSet.xAxis.labelTextStyle = textStyle;
axisSet.yAxis.labelTextStyle = textStyle;
axisSet.xAxis.labelOffset = 3.0f;
axisSet.yAxis.labelOffset = 3.0f;
//set axes' line styles and interval ticks
CPTMutableLineStyle *lineStyle = [CPTMutableLineStyle lineStyle];
lineStyle.lineColor = [CPTColor whiteColor];
lineStyle.lineWidth = 3.0f;
axisSet.xAxis.axisLineStyle = lineStyle;
axisSet.yAxis.axisLineStyle = lineStyle;
axisSet.xAxis.majorTickLineStyle = lineStyle;
axisSet.yAxis.majorTickLineStyle = lineStyle;
axisSet.xAxis.majorIntervalLength = CPTDecimalFromFloat(5.0f);
axisSet.yAxis.majorIntervalLength = CPTDecimalFromFloat(5.0f);
axisSet.xAxis.majorTickLength = 10.0f;
axisSet.yAxis.majorTickLength = 10.0f;
axisSet.xAxis.minorTickLineStyle = lineStyle;
axisSet.yAxis.minorTickLineStyle = lineStyle;
axisSet.xAxis.minorTicksPerInterval = 1;
axisSet.yAxis.minorTicksPerInterval = 1;
axisSet.xAxis.minorTickLength = .0f;
axisSet.yAxis.minorTickLength = .0f;
axisSet.xAxis.labelFormatter = labelFormatter;
axisSet.yAxis.labelFormatter = labelFormatter;
// Create bar plot and add it to the graph
CPTBarPlot *plot = [[CPTBarPlot alloc] init] ;
plot.dataSource = self;
plot.delegate = self;
plot.barWidth = [[NSDecimalNumber decimalNumberWithString:@"10.0"]
decimalValue];
plot.barOffset = [[NSDecimalNumber decimalNumberWithString:@"10.0"]
decimalValue];
plot.barCornerRadius = 5.0;
// Remove bar outlines
CPTMutableLineStyle *borderLineStyle = [CPTMutableLineStyle lineStyle];
borderLineStyle.lineColor = [CPTColor greenColor];
plot.lineStyle = borderLineStyle;
// Identifiers are handy if you want multiple plots in one graph
plot.identifier = @"chocoplot";
[self.graph addPlot:plot];
}
-(NSUInteger)numberOfRecordsForPlot:(CPTPlot *)plot
{
if ( [plot.identifier isEqual:@"chocoplot"] )
{
return [self.data count];
}
return 0;
}
-(NSNumber *)numberForPlot:(CPTPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index
{
if ( [plot.identifier isEqual:@"chocoplot"] )
{
NSDictionary *bar = [self.data objectAtIndex:index];
if(fieldEnum == CPTBarPlotFieldBarLocation) {
//return [bar valueForKey:BAR_POSITION];
NSLog(@"bar position before");
return [NSNumber numberWithDouble:30];
NSLog(@"bar position after");
}
else if(fieldEnum ==CPTBarPlotFieldBarTip) {
//return [bar valueForKey:BAR_HEIGHT];
NSLog(@"bar height before");
return [NSNumber numberWithDouble:20];
NSLog(@"bar height before");
}
}
NSLog(@"numberForPlot return before");
return [NSNumber numberWithFloat:0];
NSLog(@"numberForPlot return after");
}
-(CPTLayer *)dataLabelForPlot:(CPTPlot *)plot recordIndex:(NSUInteger)index
{
if ( [plot.identifier isEqual: @"chocoplot"] )
{
CPTMutableTextStyle *textStyle = [CPTMutableTextStyle textStyle];
textStyle.fontName = @"Helvetica";
textStyle.fontSize = 14;
textStyle.color = [CPTColor whiteColor];
NSDictionary *bar = [self.data objectAtIndex:index];
CPTTextLayer *label = [[CPTTextLayer alloc] initWithText:[NSString stringWithFormat:@"%@", [bar valueForKey:@"CATEGORY"]]];
label.textStyle =textStyle;
return label;
}
CPTTextLayer *defaultLabel = [[CPTTextLayer alloc] initWithText:[NSString stringWithString:@"Label"]];
return defaultLabel;
}
-(CPTFill *)barFillForBarPlot:(CPTBarPlot *)barPlot
recordIndex:(NSUInteger)index
{
if ( [barPlot.identifier isEqual:@"chocoplot"] )
{
NSDictionary *bar = [self.data objectAtIndex:index];
CPTGradient *gradient = [CPTGradient gradientWithBeginningColor:[CPTColor whiteColor]
endingColor:[bar valueForKey:@"COLOR"]
beginningPosition:0.0 endingPosition:0.3 ];
[gradient setGradientType:CPTGradientTypeAxial];
[gradient setAngle:320.0];
CPTFill *fill = [CPTFill fillWithGradient:gradient];
return fill;
}
return [CPTFill fillWithColor:[CPTColor colorWithComponentRed:1.0 green:1.0 blue:1.0 alpha:1.0]];
}
@end