如何动态地改变核心地块的标签

我在核心地块使用自定义标签时遇到一个问题：如何动态地改变核心地块的标签

我的核心情节支持变焦。
x轴标记是定制x.axisLabels

在第一负载中，接口是正常的，但是当我缩小核心剧情，轴线标签重叠在一起。

如何设计标签上的水平？例如，当最低级别仅显示一年时，在级别显示日期中，最高级别显示日期。

- (void)initPlotGraph 
{ 
    graph = [[CPTXYGraph alloc] initWithFrame:CGRectZero]; 
    self.hostedGraph = graph; 
    locationLabels = [[NSMutableArray alloc]init]; 

    graph.plotAreaFrame.paddingLeft += 5.0; 
    graph.plotAreaFrame.paddingTop += 5.0; 
    graph.plotAreaFrame.paddingRight += 5.0; 
    graph.plotAreaFrame.paddingBottom += 17.5; 

    //[self setAllowPinchScaling:NO]; 

    // Setup scatter plot space 
    plotSpace      = (CPTXYPlotSpace *)graph.defaultPlotSpace; 
    plotSpace.allowsUserInteraction = YES; 
    plotSpace.delegate    = self; 

    plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromInt(0)length:CPTDecimalFromFloat(1+0.3)]; 
    plotSpace.globalYRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromInt(0)length:CPTDecimalFromFloat(1+0.3)]; 

    [self initPlotAxis]; 
} 

- (void)initPlotAxis 
{ 
    CPTMutableLineStyle *axisLineStyle = [CPTMutableLineStyle lineStyle]; 
    axisLineStyle.lineWidth   = 2; 
    axisLineStyle.lineColor   = [CPTColor colorWithComponentRed:CPTFloat(0.11765) green:CPTFloat(0.49804) blue:CPTFloat(0.87451) alpha:CPTFloat(1)]; 

    CPTMutableLineStyle *axisTickLineStyle = [CPTMutableLineStyle lineStyle]; 
    axisTickLineStyle.lineWidth   = 0; 

    CPTLineCap *lineCap = [CPTLineCap sweptArrowPlotLineCap]; 
    lineCap.size  = CGSizeMake(10, 10); 
    lineCap.lineCapType = CPTLineCapTypeNone; 

    // Axes 
    // Label x axis with a fixed interval policy 
    lineCap.lineStyle  = axisLineStyle; 
    lineCap.fill   = [CPTFill fillWithColor:[CPTColor colorWithComponentRed:CPTFloat(0.29019) green:CPTFloat(0.54118) blue:CPTFloat(0.76471) alpha:CPTFloat(1)]]; 
    CPTXYAxisSet *axisSet = (CPTXYAxisSet *)graph.axisSet; 
    CPTXYAxis *x   = axisSet.xAxis; 
    x.majorIntervalLength = CPTDecimalFromInt(1); 
    x.axisLineStyle  = axisLineStyle; 
    x.axisConstraints  = [CPTConstraints constraintWithRelativeOffset:0]; 
    x.axisLineCapMax  = lineCap; 
    x.axisLabels   = [self buildLabelTitle]; 
    x.labelingPolicy  = CPTAxisLabelingPolicyNone; 
    x.minorTickLocations = [NSSet setWithArray:locationLabels]; 

    // Label y with an automatic label policy. 
    lineCap.lineStyle  = axisLineStyle; 
    lineCap.fill   = [CPTFill fillWithColor:[CPTColor colorWithComponentRed:CPTFloat(0.29019) green:CPTFloat(0.54118) blue:CPTFloat(0.76471) alpha:CPTFloat(1)]]; 
    CPTXYAxis *y = axisSet.yAxis; 
    // y.majorIntervalLength = CPTDecimalFromDouble(5); 
    y.majorTickLineStyle = axisTickLineStyle; 
    y.minorTickLineStyle = axisTickLineStyle; 
    y.axisLineStyle   = axisLineStyle; 
    y.axisLineCapMax  = lineCap; 
    y.axisConstraints  = [CPTConstraints constraintWithRelativeOffset:0]; 

    // Set axes 
    graph.axisSet.axes = [NSArray arrayWithObjects:x, y, nil]; 
} 

- (NSMutableSet*)buildLabelTitle 
{ 
    NSMutableSet *newAxisLabels = [NSMutableSet set]; 

    CPTMutableTextStyle *textStyleB = [CPTMutableTextStyle textStyle]; 
    textStyleB.color = [CPTColor colorWithComponentRed:CPTFloat((float)0x09/0xFF) green:CPTFloat((float)0x31/0xFF) blue:CPTFloat((float)0x4A/0xFF) alpha:CPTFloat(1)]; 

    plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromInt(corePlotNums - 9)length:CPTDecimalFromInt(10)]; 
    plotSpace.globalXRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromInt(0) length:CPTDecimalFromInt(corePlotNums + 1)]; 

    for (NSUInteger i = 1; i < corePlotNums + 1; i++) 
    { 
     CPTAxisLabel *newLabel = [[CPTAxisLabel alloc] initWithText:[[m_labelStr objectAtIndex:i-1] substringWithRange:NSMakeRange(5, 11)] textStyle:textStyleB]; 
     newLabel.tickLocation = CPTDecimalFromUnsignedInteger(i); 
     newLabel.offset = 5; 
     [newAxisLabels addObject:newLabel]; 
     [newLabel release]; 
    } 

    return newAxisLabels; 
}

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