iOS核心繪圖CPTAxisLabel與CPTPlot對齊

請看下面的這張圖片。我附加了文件。我的問題與CPTAxisLabel標籤。他們被放在勾號下，但他們不是根據我想要的CPTPlot。iOS核心繪圖CPTAxisLabel與CPTPlot對齊

如何爲此標籤添加左偏移量？我需要將我的標籤放在CPTPlot對象的中間。

enter image description here

（修訂版:)

-(void)configureGraph 
{ 

    NSInteger max = 0; 
    for (NSNumber *number in self.values) { 
     NSInteger num = [number integerValue]; 
     if (num > max) { 
      max = num; 
     } 
    } 

    CPTGraph *graph = [[CPTXYGraph alloc] initWithFrame:self.bounds]; 

    graph.plotAreaFrame.masksToBorder = NO; 

    self.hostedGraph = graph; 

    graph.paddingBottom = 80.0f; 
    graph.paddingLeft = 0.0f; 
    graph.paddingTop = 50.0f; 
    graph.paddingRight = 0.0f; 

    CGFloat xMin = -0.5f; 
    CGFloat xMax = [self.titles count]; 
    if (xMax < 7.0) { 
     xMax = 7.0; 
    } 
    CGFloat yMin = 0.0f; 
    CGFloat yMax = max + 25; 

    CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *) graph.defaultPlotSpace; 
    plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(xMin) length:CPTDecimalFromFloat(xMax)]; 
    plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(yMin) length:CPTDecimalFromFloat(yMax)]; 

    //graph.backgroundColor = [[UIColor grayColor] CGColor]; 
    //graph.plotAreaFrame.fill = [CPTFill fillWithColor:[CPTColor redColor]]; 

} 

-(void)configurePlots 
{  
    CPTBarPlot *plot = [[CPTBarPlot alloc] init]; 
    //plot.barOffset = CPTDecimalFromFloat(0.30); 
    plot.fill = [CPTFill fillWithColor:[CPTColor colorWithComponentRed:190.0f/255.0f green:203.0f/255.0f blue:103.0f/255.0f alpha:1.0]]; 
    //plot.barWidth = CPTDecimalFromDouble(0.75); 
    plot.lineStyle = nil; 
    plot.barCornerRadius = 1.0; 
    plot.dataSource = self; 
    plot.delegate = self; 

    CPTGraph *graph = self.hostedGraph; 
    [graph addPlot:plot toPlotSpace:graph.defaultPlotSpace]; 

} 

#pragma mark - CPTPlotDataSource methods 
-(NSUInteger)numberOfRecordsForPlot:(CPTPlot *)plot { 
    return [self.titles count]; 
} 

-(NSNumber *)numberForPlot:(CPTPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index { 
    if ((fieldEnum == CPTBarPlotFieldBarTip) && (index < [self.titles count])) { 
      return [self.values objectAtIndex:index]; 
    } 
    return [NSDecimalNumber numberWithUnsignedInteger:index]; 
} 

-(CPTLayer *)dataLabelForPlot:(CPTPlot *)plot recordIndex:(NSUInteger)idx 
{ 

    plot.labelOffset = 0; 

    CPTMutableTextStyle *style = [CPTMutableTextStyle textStyle]; 
    style.color = [[CPTColor whiteColor] colorWithAlphaComponent:1]; 
    style.fontName = @"Helvetica-Bold"; 
    style.fontSize = 12.0f; 

    NSString *valueString = [NSString stringWithFormat:@"%@", [self.values objectAtIndex:idx]]; 

    return [[CPTTextLayer alloc] initWithText:valueString style:style]; 
} 

- (void)configureAxes 
{ 

    CPTXYAxisSet *axisSet = (CPTXYAxisSet *) self.hostedGraph.axisSet; 
    axisSet.xAxis.hidden = YES; 
    axisSet.yAxis.hidden = YES; 

    CPTMutableTextStyle *style = [CPTMutableTextStyle textStyle]; 
    style.color = [[CPTColor whiteColor] colorWithAlphaComponent:1]; 
    style.fontName = @"Helvetica-Bold"; 
    style.fontSize = 12.0f; 

    NSMutableArray *labels = [[NSMutableArray alloc] initWithCapacity:5]; 
    int idx =0; 
    for (NSString *string in self.titles) 
    { 
     CPTAxisLabel *label = [[CPTAxisLabel alloc] initWithText:string textStyle:style]; 
     label.rotation = M_PI/2; 
     label.tickLocation = CPTDecimalFromInt(idx); 
     label.offset = 10.0f; 
     [labels addObject:label]; 
     idx+=1; 
    } 

    axisSet.xAxis.axisLabels = [NSSet setWithArray:labels]; 
}

來源

2013-03-28 Matrosov Alexander