willChangePlotRangeTo：对Core Plot中的图没有影响 [英] willChangePlotRangeTo: makes no difference to graphs in Core Plot

问题描述

我在我的应用中运行了以下代码，以防止在触摸或捏合手势期间缩放y轴。我已经分配了axisConstraints，也已经分配了globalXRange和Y。

i have the below code running in my app to stop the y-axis from being zoomed and scaled during touch or pinch gestures. I have axisConstraints assigned already, as are the globalXRange and Y.

-(CGPoint)plotSpace:(CPTPlotSpace *)space willChangePlotRangeTo:(CGPoint)displacement{
return CGPointMake(displacement.x,0);
}

-(CPTPlotRange *)plotSpace:(CPTPlotSpace *)space
 willChangePlotRangeTo:(CPTPlotRange *)newRange
         forCoordinate:(CPTCoordinate)coordinate{
if (coordinate == CPTCoordinateY)
{
    newRange = ((CPTXYPlotSpace*)space).yRange;
}
NSLog(@"Plot changes %@", newRange);
return newRange;
}

我的问题是从日志中记录了4-5个地块变化首次运行应用程序时页面首次显示时的日志？该代码似乎正常工作，只是我没有得到任何图，而且Y上也没有标签和刻度。

My issue is that from the logs, 4-5 plot changes are recorded in the log while the page is first displaying when first running the app?? The code seems to work correctly, just i get no plots, plus no label + ticks on the Y.

2013-11-10 17:30:52.259 MyApp[8953:a0b] Pinch changes <<CPTPlotRange: 0x8d96680> {0, 30158.4}>
2013-11-10 17:30:52.260 MyApp[8953:a0b] Pinch changes <<CPTPlotRange: 0x8d94e70> {0, 40}>
2013-11-10 17:30:52.260 MyApp[8953:a0b] Pinch changes <<CPTPlotRange: 0x8d94330> {0, 34.44}>
2013-11-10 17:30:52.268 MyApp[8953:a0b] Pinch changes <<CPTPlotRange: 0x8da6da0> {0, 30158}>
2013-11-10 17:30:52.268 MyApp[8953:a0b] Pinch changes <<CPTPlotRange: 0x8da80e0> {0, 9}>

编辑：

我做了些混帐随即插入NSLOG，下面的代码创建了一个手势：

I did some mucking around with inserting NSLOG and the below code is what is creating the a gesture:

CPTXYPlotSpace *plotSpace2 = (CPTXYPlotSpace *) graph2.defaultPlotSpace;
plotSpace2.allowsUserInteraction = YES;
plotSpace2.delegate = self;
plotSpace2.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0) length:CPTDecimalFromInteger([difference integerValue]*1.03)];
plotSpace2.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0) length:CPTDecimalFromFloat(9)];
plotSpace2.globalXRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0) length:CPTDecimalFromInteger([difference integerValue]*1.03)];
plotSpace2.globalYRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0) length:CPTDecimalFromFloat(9)];

所以有plotspace.delegate = self是原因，更改为x.delegate = self并解决了

so having plotspace.delegate=self was the cause, changed to x.delegate=self and that fixes the gesture issue i was seeing.

不幸的是，我只缩放x的代码没有任何区别。 ：-/

Unfortunately the code i have for zooming only the x makes no difference. :-/

推荐答案

您的代理人禁止对 yRange 进行任何更改。在设置初始 yRange 之后，设置绘图空间委托。

Your delegate is preventing any changes to the yRange. Set the plot space delegate after you set up the initial yRange.

plotSpace2.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0)
                                                 length:CPTDecimalFromFloat(9)];
plotSpace2.delegate = self;

此行为在1.4版中已更改。在以前的版本中，仅在缩放时才调用 -plotSpace：willChangePlotRangeTo：forCoordinate：。现在，只要绘图范围发生变化，就可以调用它。

This behavior changed in release 1.4. In prior releases, -plotSpace:willChangePlotRangeTo:forCoordinate: was only called when pinch-scaling. Now, it is called any time the plot range changes.

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