iphone - 如何在iPhone上使用Core-Plot折线图实现放大和缩小？

Question

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

提前致谢。

Answer 1

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，但我能想到的最好的解决方案):

-(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)];
}