I want to use the mouse to select (or highlight) a single column. I have set at design time:
MouseAction .ColSelect = true
MouseActions DisjuntColSelect = true
and when I run the program and display the grid I can click on a column heading and the column is highlighted .. perfect. But if I hold down the shift key and click another column I now have 2 columns selected. If I first display the grid and click in an empty area then all columns are highlighted.
How can I get the grid to ONLY highlight the column I click in?
It is by design that when you click & shift drag it selects multiple columns, just like it selects multiple columns when you ctrl-click. I could not reproduce that all columns are selected when you click in an empty area. Do you use the latest version of the component? If so, are there other properties with non default settings involved or event handlers you wrote?
I incorrectly stated that it highlighted all columns. It only highlighted column 0 and column 1. I believe column 1 was already highlighted so it highlighted all preceding I think.
What I think you probably see is that when you set focus to the grid, the column where the cell that gets focus (there is always one focused cell), becomes highlighted (which is expected as it is setup to always select an entire column)
That may be it. How do I 'set focus' to the highlighted column? What I do when I first display the grid is unselect all columns then select column 1. When I click on the grid it highlights column 0. So what I probably need to do is select the column and set focus.
If you'd select column 1 programmatically, I'd suggest to first set grid.Col := 1;