How to find out who is Sender of TDBGrid OnTitleClick event handler?
lazarus / 16-Databases

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Vodnik · 2021-01-08 17:03

I'm using DBgrid's OnTitleClick event for sorting purposes, as
described here:
https://wiki.lazarus.freepascal.org/Grids_Reference_Page#Sorting_colum
ns_or_rows_in_DBGrid_with_sort_arrows_in_column_header

This example works fine. In my application I have several DBGrids and
would like to make an universal OnTitleClick procedure, applicable for
any DBGrid. Unfortunately, OnTitleClick handler do not provide Sender
parameter, so I don't know which DBGrid have initiated it.

I have tried OnMouseDown event (which provides the Sender), in
principle it can be used, but have disadvantages, e.g. it hits also
when user changes the column width or moves the column

Please help with ideas how to find out Sender of OnTitleClick event or
make this procedure universal?

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Lutz Mändle · 2021-01-08 18:57

The Column parameter has a Grid property which references to the
DBGrid where the column resides.

If you using FPC 3.2 or newer, the property IndexFieldNames of the
underlying dataset can used for sorting (ascending and descending),
simply assign a string with the columnfieldnames (separated with
semicolons). For descending sorting append a ' DESC' to the individual
fieldname (leading space is important). This only sorts the dataset,
the sort arrow of the column title has to determined in the manner
shown in the wiki example (assigning an imagelist to the grid and set
the property Column.Title.ImageIndex accordingly).

HTH

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Vodnik · 2021-01-08 20:24

Thanks, Lutz Mändle, you have made my day!
I felt that there should be something like this Grid property in
TColumn, but couldn't find it by myself...