| Subject | Problem with IB_ComboBox on IB_Grid in Delphi XE3, Windows 7 |
|---|---|
| Author | Adrian Wreyford |
| Post date | 2013-02-17T09:22:10Z |
Dear List,
I have tried to resolve this issue with Jason since Delphi XE, Win7 in August 2011.
Eventually I resorted to using Telesis Enhanced components of Geoff Worboys, after he helped me get it installed in XE.
What I then did, was to replace all my IB_ComboBoxes that I dropped on IB_Grids and replaced with IB_ComboBoxEnh to overcome this problem.
Unfortunately I have been unable to raise Geoff to try and get his component set installed in XE3.
Unfortunately there are some major VCL changes that impact on his code, and not just a matter of a few tweaks to get working.
So then I had to resort to removing all the IB_ComboBoxEnh controls that I had dropped on IB_Grids in all my projects, and systematically replaced with IB_ComboBox, and all compiled just fine, until I started testing my apps, and the horror bug resurfaced.
Well lets try explain what happens.
I open my application on the desktop, and the desktop screen size bigger than the program window.
When I click on one of the comboboxes in the grid, the actual dropdownlist displays on the screen at the top left corner of the screen, and not on the grid itself.
It just flashes, thus making any sort of input impossible.
When hovering with cursor over the actual Combobox on the grid a lot of flickering goes on, as if is being redrawn over and over
I use an IB_Grid, with :
DefaultRowHeight = 26
I drop a IB_ComboBox on the grid and set as follows.
Style = csDropDownList
I then set the Items and Itemvalues I need, and the DataField and DataSource.
Note that in XE3, you cannot change the Height or ItemHeight for the component once dropped on the grid.
It remains 24 / 16.
When you create a new form, drop the grid on it and one combobox, and link to datasource, and make the form smaller than your desktop, and then run it, you will see the actual dropdown list display off the active window on the desktop top left corner.
It appears as though the handle for the dropdownlist is somehow getting confused.
Well, as you can imagine this is quite a show stopper.
Any advice to repair this will be appreciated.
In 2011 when Geoff helped me get the Telesis Components to compile for XE, he mentioned the following in an email:
Regards
Adrian
[Non-text portions of this message have been removed]
I have tried to resolve this issue with Jason since Delphi XE, Win7 in August 2011.
Eventually I resorted to using Telesis Enhanced components of Geoff Worboys, after he helped me get it installed in XE.
What I then did, was to replace all my IB_ComboBoxes that I dropped on IB_Grids and replaced with IB_ComboBoxEnh to overcome this problem.
Unfortunately I have been unable to raise Geoff to try and get his component set installed in XE3.
Unfortunately there are some major VCL changes that impact on his code, and not just a matter of a few tweaks to get working.
So then I had to resort to removing all the IB_ComboBoxEnh controls that I had dropped on IB_Grids in all my projects, and systematically replaced with IB_ComboBox, and all compiled just fine, until I started testing my apps, and the horror bug resurfaced.
Well lets try explain what happens.
I open my application on the desktop, and the desktop screen size bigger than the program window.
When I click on one of the comboboxes in the grid, the actual dropdownlist displays on the screen at the top left corner of the screen, and not on the grid itself.
It just flashes, thus making any sort of input impossible.
When hovering with cursor over the actual Combobox on the grid a lot of flickering goes on, as if is being redrawn over and over
I use an IB_Grid, with :
DefaultRowHeight = 26
I drop a IB_ComboBox on the grid and set as follows.
Style = csDropDownList
I then set the Items and Itemvalues I need, and the DataField and DataSource.
Note that in XE3, you cannot change the Height or ItemHeight for the component once dropped on the grid.
It remains 24 / 16.
When you create a new form, drop the grid on it and one combobox, and link to datasource, and make the form smaller than your desktop, and then run it, you will see the actual dropdown list display off the active window on the desktop top left corner.
It appears as though the handle for the dropdownlist is somehow getting confused.
Well, as you can imagine this is quite a show stopper.
Any advice to repair this will be appreciated.
In 2011 when Geoff helped me get the Telesis Components to compile for XE, he mentioned the following in an email:
>> It seems that there are some big problems with this arrangementWell I hope you understand.
>> under Windows 7.
>> the grid is constantly repainting, driving one cpu to 100%
>> the dropdown paints in the top-left (not the top right here)
>> it seems to work as expected under Windows XP (the exact
>> same executable - as compiled under Delphi 2010), so the
>> problem is either a Windows bug or at least a difference.
>> (Not the first: listbox reactions to Ctl3D seem to be
>> reversed in Windows 7.)
>>
>> I just tried my TIB_ComboBoxEnh control in your sample app and
>> it works as expected (places the dropdown in the right place
>> and does not cause the cpu to go crazy).
Regards
Adrian
[Non-text portions of this message have been removed]