TaChart.Axis.Marks.Format invalid value causes Lazarus to chash
lazarus / 55-TAChart

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typo · 2010-04-10 16:12

BTW, how to set the value of this property? Which are the valid
values?

Changing TaChart.Axis.Marks.Style to smsLabel at design time causes
Lazarus to crash. But until now I could not hit a valid value for this
property.

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Ask · 2010-04-11 04:21

Lazarus does not literally "crash", it issues an exception with
"Invalid index in format" message,
which is correct, although not very informative.
You are welcome to create a bug report (see link to Bugtracker on the
left pane)
with your suggestions on the better error message.

The value of Format property itself is a string passed to the standard
Format
function to convert marks to text.
In the case of "normal" marks, Format receives only one second
argument, so
format string may contain only "%0" argument reference.
Other references are useful when you are creating customized marks by
assigning Marks.Source property.
See example project in components/tachart/demo/axis/, "Customized
Marks" page.

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typo · 2010-04-11 07:07

I need that instead of numbers as marks, there are labels. I need that
beside each bar there is a label, indeed a word. I tried to change the
Style property to labels, but I couldn't.

I think that changing Style property to another value should set a
valid Format property value by itself. I tried all settings of format
that I could find. Also changing Style property causes the same "error
message".

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Ask · 2010-04-11 07:16

QuoteI need that instead of numbers as marks, there are labels. I need
that beside each bar there is a label, indeed a word. I tried to
change the Style property to labels, but I couldn't.

Those labels have to come from somewhere, so you must assign
Marks.Source property.
See example project in components/tachart/demo/axis/, "Customized
Marks" page.

QuoteI think that changing Style property to another value should set
a valid Format property value by itself.

It does, for the cases when there is a suitable marks source.
See example project in components/tachart/demo/axis/, "Customized
Marks" page.

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typo · 2010-04-11 07:31

Setting a Source property solves the problem. OK.

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typo · 2010-04-11 07:37

Setting Source to None causes the same error.

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typo · 2010-04-11 08:33

I don't think that behavior of the component is really a bug, only
that the TAChart is a component too complex for my simple purposes.

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Ask · 2010-04-11 08:47

Well, while not a "correctness" bug, it still was a usability bug.
Please try r24575 -- should be improved slightly.

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typo · 2010-04-11 11:16

Anyway, I created the bug report.

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Ask · 2010-04-12 06:12

Did you? I do not see it on the bugtracker.

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typo · 2010-04-12 07:12

http://bugs.freepascal.org/view.php?id=16254

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jhonson01 · 2013-07-23 20:29

Para que puedas ejecutar el smsLabel debes inculir en uses el
TAChartUtils... a mi me funciono asi...

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wp · 2013-07-23 21:59

Could somebody please translate the preceding posting to English?