[Lazarus] [lazarus-br] Re: Como passar uma procedure local como callback?

Hans-Peter Diettrich DrDiettrich1 at aol.com
Wed Feb 22 00:01:10 CET 2012


waldo kitty schrieb:

> eg: http://www.freepascal.org/docs-html/rtl/sysutils/datetostr.html
> 
> there should be sample output and definitely something for the 
> formatsettings... 
> http://www.freepascal.org/docs-html/rtl/sysutils/tformatsettings.html 
> definitely doesn't help and i spent hours digging in there (the site) 
> trying to find something... i finally got to 
> http://www.freepascal.org/docs-html/rtl/sysutils/formatdatetime.html and 
> found a little bit of help which i still had to guess at some stuff and 
> i have *just now* noticed the link to 
> http://www.freepascal.org/docs-html/rtl/sysutils/formatchars.html which 
> appears to offer more than what i had found before... but even that page 
> needs some concrete alpha-numerical examples of what the output would 
> look like...

Please suggest a pleasant solution. Perhaps a separate overview topic 
could be added, explaining the date and time formatting. "Using Dates 
and Times"...


>> While RTL and FCL topics can be demonstrated in simple console 
>> applications, LCL
>> topics usually require big sample applications. See how e.g.
>> examples/listview/listview.lpi demonstrates the capabilities of a 
>> TListView.
> 
> i see it, yes but i'm lost in all the other controls' code in there...

This example demonstrates the effects of various property settings, and 
how to access detailed information in code.

> running the project doesn't help me to understand a listview, either :?  
> yes, i see the effect of some of the controls but, for example, it is 
> not clear to me why i can select "new 1" or "New 2" but not "Sub 1"...

A ListView is not a Grid.

> neither is it clear to me what the items and columns tabs are for...

It should be obvious, from the buttons in those pages, that they 
demonstrate adding and removing items and columns.

> i 
> can't even get anything to react when i choose the columns tab and click 
> about :(

The About menu shows information about the application, not help.

Again feel free to supply whatever you think would be better :-)
Topic "Using ListView"?


>> About things like callback functions, which are common to many 
>> components, there
>> should exist references to examples that *also* demonstrate such 
>> features,
>> amongst possibly many others.
> 
> agreed... i think... but yes, everything should be documented that can 
> be... even basic things like what a "callback" is... i see/hear that and 
> i think telco stuff :(
Topic "Using Callbacks"?

DoDi





More information about the Lazarus mailing list