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组件实施放大和缩小？

解决方案

是的，我的方式是通过调整PlotSpace这样（可能不是最好的解决方案，但最好的一个，我可以想出）：

   - （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）]; 
} 
  

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?

Thanks in advance.

解决方案

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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