PieChartView Can not highlight which i want to highlighted

[codeliu6572]

I use PieChartView and want to highlighted one after init.I see lineChar can use
[self.chartView highlightValueWithX:0.0f y:0.0f dataSetIndex:3 callDelegate:NO];
and I test in piechart ,because piechart don't have an x and y,so,I give x and y 0.0f,and give SetIndex the index in the array, but it does not work except index=0,i want to know how to highlighted some one i wanted in piechart.Thankyou!

Expect your reply!

[codeliu6572]

@liuxuan30 Can you show me how to highlight index greater than zero？I tried and it does not work.
chartView.highlightValue(x: 0.0, y: 0.0, dataSetIndex: 0, callDelegate: false)
Only when index is zero, it can work, why? I need index greater than zero, what should i do?

[liuxuan30]

don't use coordinate if you are not familiar with. There are plenty of highlight methods, so use others. like @objc open func highlightValue(_ highlight: Highlight?)

[codeliu6572]

@liuxuan30 I tried this
ChartHighlight *high = [[ChartHighlight alloc]init];
high.dataIndex = maxIndex;
[self.chartView highlightValue:high];
dataSetIndex is readonly and can not use,I searched on the internet and find nothing about it, can you show me how to use highlight on piechart?Thank you.

[liuxuan30]

I think you misunderstood? usually what you need to provide is data set index and entry index, etc, to only identify which entry in which data set to be used. DataIndex is only used in combined chart, in pie chart, dataSetIndex and dataIndex should always be 0 I suppose.

[liuxuan30]

BTW, Try debug ChartDemo - pie chart, it has all the steps how highlight are created and highlighted. You can add a breakpoint at drawHighlighted method

[codeliu6572]

@liuxuan30 You mean If i need to highlight one part of Piechart , i have to rewrite some method? If ChartDemo - pie chart has method ,can you tell me how to use it? I found highlight method contains x,y,even highlightValue(_ highlight: Highlight?) ,I googled bug found nothing useful,I suggest you add highlight method on PIeChartView.

[codeliu6572]

@liuxuan30 I have solved this problem by using
[_chartView highlightValueWithX:4 dataSetIndex:0];

dataSetIndex is zero, and X is the index, but i don not understand why this work, but it solved my problem.Thanks anyway!Here I was to suggest your team write right method in the Demo to help developer, like me,I think most of developer will meet this problem,and your team certainly hope to let Charts more better.
Best wishes for you and your team!

[liuxuan30]

highlightValue API series eventually lead to the same final call. You can take a look at open override func drawHighlighted(context: CGContext, indices: [Highlight]) how your code work, and maybe you can find a better one.

BTW, pie chart by default nil-ed x axis. So pie chart does not have x axis

Thanks for your input. We will improve that. Well, if we got enough complains about that :)

[codeliu6572]

Haha，I have seen some issues on GitHub,Really hope you improve that .Although it worked,i still worried some unknown question. If i rewrite this method, but you update some code ,you know, maybe
have other question. Hope your update.