我从核心情节开始,遇到了一些问题。我按照本页的教程操作: http://www.switchonthecode.com/tutorials/using-core-plot-in-an-iphone-application

并完成本页的说明: http://code.google.com/p/core-plot/wiki/UsingCorePlotInApplications (例如-所有负载)。

但我仍然有一些问题,我得到以下错误:

error: incompatible type for argument 1 of 'setMajorIntervalLength:'
error: request for member 'axisLabelOffset' in something not a structure or union
error: incompatible type for argument 1 of 'setMajorIntervalLength:'
error: request for member 'axisLabelOffset' in something not a structure or union
error: request for member 'bounds' in something not a structure or union
error: request for member 'defaultPlotSymbol' in something not a structure or union
error: request for member 'bounds' in something not a structure or union

谁知道我做错了什么? 这是我的代码:

- (void)viewDidLoad {
    [super viewDidLoad];

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

    CPLayerHostingView *hostingView = (CPLayerHostingView *)self.view;
    hostingView.hostedLayer = graph;
    graph.paddingLeft = 20.0;
    graph.paddingTop = 20.0;
    graph.paddingRight = 20.0;
    graph.paddingBottom = 20.0;

    CPXYPlotSpace *plotSpace = (CPXYPlotSpace *)graph.defaultPlotSpace;
    plotSpace.xRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromFloat(-6)
                                                   length:CPDecimalFromFloat(12)];
    plotSpace.yRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromFloat(-5)
                                                   length:CPDecimalFromFloat(30)];

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

    CPLineStyle *lineStyle = [CPLineStyle lineStyle];
    lineStyle.lineColor = [CPColor blackColor];
    lineStyle.lineWidth = 2.0f;

    axisSet.xAxis.majorIntervalLength = [NSDecimalNumber decimalNumberWithString:@"5"];
    axisSet.xAxis.minorTicksPerInterval = 4;
    axisSet.xAxis.majorTickLineStyle = lineStyle;
    axisSet.xAxis.minorTickLineStyle = lineStyle;
    axisSet.xAxis.axisLineStyle = lineStyle;
    axisSet.xAxis.minorTickLength = 5.0f;
    axisSet.xAxis.majorTickLength = 7.0f;
    axisSet.xAxis.axisLabelOffset = 3.0f;

    axisSet.yAxis.majorIntervalLength = [NSDecimalNumber decimalNumberWithString:@"5"];
    axisSet.yAxis.minorTicksPerInterval = 4;
    axisSet.yAxis.majorTickLineStyle = lineStyle;
    axisSet.yAxis.minorTickLineStyle = lineStyle;
    axisSet.yAxis.axisLineStyle = lineStyle;
    axisSet.yAxis.minorTickLength = 5.0f;
    axisSet.yAxis.majorTickLength = 7.0f;
    axisSet.yAxis.axisLabelOffset = 3.0f;

    CPScatterPlot *xSquaredPlot = [[[CPScatterPlot alloc]
                                    initWithFrame:graph.defaultPlotSpace.bounds] autorelease];
    xSquaredPlot.identifier = @"X Squared Plot";
    xSquaredPlot.dataLineStyle.lineWidth = 1.0f;
    xSquaredPlot.dataLineStyle.lineColor = [CPColor redColor];
    xSquaredPlot.dataSource = self;
    [graph addPlot:xSquaredPlot];

    CPPlotSymbol *greenCirclePlotSymbol = [CPPlotSymbol ellipsePlotSymbol];
    greenCirclePlotSymbol.fill = [CPFill fillWithColor:[CPColor greenColor]];
    greenCirclePlotSymbol.size = CGSizeMake(2.0, 2.0);
    xSquaredPlot.defaultPlotSymbol = greenCirclePlotSymbol;  

    CPScatterPlot *xInversePlot = [[[CPScatterPlot alloc]
                                    initWithFrame:graph.defaultPlotSpace.bounds] autorelease];
    xInversePlot.identifier = @"X Inverse Plot";
    xInversePlot.dataLineStyle.lineWidth = 1.0f;
    xInversePlot.dataLineStyle.lineColor = [CPColor blueColor];
    xInversePlot.dataSource = self;
    [graph addPlot:xInversePlot];
}