CorePlot LineGraph - 悬停/点击图表查看值 - macOS

Question

我正在使用CorePlot在我的macOS应用程序中绘制一个简单的线图.

CPTXYGraph *newGraph = [[CPTXYGraph alloc] initWithFrame:CGRectZero];

CPTTheme *theme      = [CPTTheme themeNamed:kCPTDarkGradientTheme];
[newGraph applyTheme:theme];
self.graph = newGraph;
self.hostView.hostedGraph = newGraph;

newGraph.plotAreaFrame.paddingTop   = 10.0;
newGraph.plotAreaFrame.paddingBottom   = 30.0;
newGraph.plotAreaFrame.paddingLeft   = 40.0;
newGraph.plotAreaFrame.paddingRight  = 10.0;

CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)newGraph.defaultPlotSpace;
    plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:@(1.0) length:[NSNumber numberWithUnsignedInteger:[dataArray count]-1]];
    plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:@0.0 length:@102.0];
    plotSpace.allowsUserInteraction = YES;

CPTXYAxisSet *axisSet = (CPTXYAxisSet *)newGraph.axisSet;
    CPTXYAxis *x          = axisSet.xAxis;
    //x.majorIntervalLength   = @1;
    x.majorIntervalLength   = [NSNumber numberWithInt:numberOfIntervalsX];
    x.orthogonalPosition    = @(0);
    x.minorTicksPerInterval = 0;
    x.labelOffset  = 0;

    CPTXYAxis *y = axisSet.yAxis;
    y.majorIntervalLength   = @5;
    y.minorTicksPerInterval = 0;
    y.orthogonalPosition    = @(1.0);
    y.labelOffset  = 0.0;

CPTScatterPlot *dataSourceLinePlot = [[CPTScatterPlot alloc] init];
    CPTMutableLineStyle *lineStyle = [dataSourceLinePlot.dataLineStyle mutableCopy];
    lineStyle.lineWidth              = 2.;
    lineStyle.lineColor              = [CPTColor greenColor];
    dataSourceLinePlot.dataLineStyle = lineStyle;


    dataSourceLinePlot.dataSource = self;
    [newGraph addPlot:dataSourceLinePlot];

我期待悬停/点击查看值将是默认行为,但看起来不是.我试过搜索论坛但没有运气.我假设它真的很直接.不确定我是否遗漏了什么.

Answer 1

据我所知，您的印象是正确的，没有内置的数据值叠加。不过，您可以自己制作。CorePlot 的功能indexOfVisiblePointClosestToPlotAreaPoint:应该为您提供向图表添加带有点值的标签所需的参考。

• (NSUInteger)indexOfVisiblePointClosestToPlotAreaPoint：

返回最近点的索引，如果没有可见点则返回 NSNotFound。

然后，您可以对图形托管视图进行子类化，实现鼠标移动事件来捕获鼠标坐标，并从那里执行您想要选择如何显示点的任何逻辑。

我不会说它特别容易实现，但至少它是直接的。我希望它有帮助！

参考：

http://core-plot.github.io/MacOS/interface_c_p_t_scatter_plot.html#a57eacc8261a4d4a1399f1196be786cff /sf/answers/1527353971/