如何在 iPhone 上使用 Core-Plot 折线图实现放大和缩小? [英] How to implement Zoom-in and Zoom-Out with Core-Plot line chart on iPhone?

问题描述

是否可以在 iPhone 上使用 Core-Plot Chart 组件实现放大和缩小?如果是这样，请建议我怎么做?

Is it possible to implement Zoom-in and Zoom-Out with Core-Plot Chart component on iPhone? If so please suggest me how to do it?

提前致谢.

推荐答案

是的，我这样做的方法是像这样调整 PlotSpace(可能不是最好的解决方案，但我能想出的最好的一个):

Yes, The way I do it is by adjusting the PlotSpace like so (probably not the best solution, but the best one i could come up with):

-(void)zoomOut 
{
    CPXYPlotSpace *plotSpace = (CPXYPlotSpace *)graph.defaultPlotSpace;

    graphScaleX+=5;
    graphScaleY+=5;

    plotSpace.xRange = [CPPlotRange plotRangeWithLocation:plotSpace.xRange.location length:CPDecimalFromFloat(graphScaleX)];
    plotSpace.yRange = [CPPlotRange plotRangeWithLocation:plotSpace.yRange.location length:CPDecimalFromFloat(graphScaleY)];
}

-(void)zoomIn
{
    CPXYPlotSpace *plotSpace = (CPXYPlotSpace *)graph.defaultPlotSpace;

    graphScaleX-=5;
    graphScaleY-=5;

    plotSpace.xRange = [CPPlotRange plotRangeWithLocation:plotSpace.xRange.location length:CPDecimalFromFloat(graphScaleX)];
    plotSpace.yRange = [CPPlotRange plotRangeWithLocation:plotSpace.yRange.location length:CPDecimalFromFloat(graphScaleY)];
}

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