使用核心图iphone的分组条形图示例？

Question

我想知道如何创建分组条形图？我试过了，但我只有一个条形图。

下面是我的代码任何一个告诉我什么是错误。

谢谢

-(void)viewDidLoad { 

    [super viewDidLoad]; 

[self generateDataSamples]; 

double xAxisStart = 0; 
double xAxisLength = [samples count]; 

double yAxisStart = 0; 
double yAxisLength = [[samples valueForKeyPath:@"@max.Y_VAL"] doubleValue]; 




    NSLog(@"xAxisLength===%f",xAxisLength); 

    NSLog(@"yAxisLength===%f",yAxisLength); 


CPGraphHostingView *hostingView = [[CPGraphHostingView alloc] initWithFrame:self.view.bounds]; 
[self.view addSubview:hostingView]; 

CPXYGraph *graph = [[CPXYGraph alloc] initWithFrame:self.view.bounds]; 
hostingView.hostedGraph = graph; 


CPXYPlotSpace *plotSpace = (CPXYPlotSpace *)graph.defaultPlotSpace; 
plotSpace.xRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromDouble(xAxisStart) 
               length:CPDecimalFromDouble(xAxisLength+1)]; 

plotSpace.yRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromDouble(yAxisStart) 
               length:CPDecimalFromDouble(yAxisLength)];  


graph.plotAreaFrame.borderLineStyle = nil; 
graph.plotAreaFrame.cornerRadius = 0.0f; 

// Paddings 
graph.paddingLeft = 0.0f; 
graph.paddingRight = 0.0f; 
graph.paddingTop = 0.0f; 
graph.paddingBottom = 0.0f; 

graph.plotAreaFrame.paddingLeft = 70.0; 
graph.plotAreaFrame.paddingTop = 20.0; 
graph.plotAreaFrame.paddingRight = 20.0; 
graph.plotAreaFrame.paddingBottom = 80.0; 




CPXYAxisSet *axisSet = (CPXYAxisSet *)graph.axisSet; 

CPXYAxis *y = axisSet.yAxis; 

    y.majorIntervalLength = CPDecimalFromString(@"1"); 
    y.orthogonalCoordinateDecimal = CPDecimalFromString(@"0"); 
y.title = @"Y Axis"; 
y.titleOffset = 45.0f; 
    y.titleLocation = CPDecimalFromFloat(3.0f); 



//first bar 
CPBarPlot *plot = [[CPBarPlot alloc] initWithFrame:CGRectZero]; 
plot.plotRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromDouble(0.0) 
              length:CPDecimalFromDouble(xAxisLength)]; 

CPFill* cpFill = [[CPFill alloc] initWithColor:[CPColor greenColor]]; 
    plot.barOffset = CPDecimalFromFloat(0.25f); 
plot.fill = cpFill; 
plot.dataSource = self; 
plot.identifier=@"plot1"; 
[graph addPlot:plot toPlotSpace:plotSpace]; 

//second bar 

plot.plotRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromDouble(1.0) 
              length:CPDecimalFromDouble(xAxisLength)]; 

CPFill* cpFill1 = [[CPFill alloc] initWithColor:[CPColor lightGrayColor]]; 
plot.fill = cpFill1; 
plot.dataSource = self; 
plot.identifier=@"plot2"; 
[graph addPlot:plot toPlotSpace:plotSpace]; 


[graph addPlot:plot]; 
[plot release]; 
[graph release]; 
[hostingView release]; 
} 

Answer 1

你永远不会创建第二个剧情对象 - 你的代码只是增加了一个相同的图形两次。您还需要确保为第二个绘图使用不同的barOffset。如果你没有使用垃圾收集，请留意你的内存管理。您的问题中的代码有几个内存泄漏。