Query - DataChange notification too often when opening

crafty · Post by **crafty** » Sun 06 Apr 2008 22:51

Hello,

I've recently encountered a problem with using SDAC (and MyDAC). If I connect a grid control to the Query (via DataSource) I get the OnFocusedRowChanged event (in grid) fired 3 times after I use Query.Open().
I've found out that other DataSet components that I use don't produce this problem so it is related to SDAC. This can be easily reproduced by testing TDataSource.OnDataChange and TDataSource.OnStateChange.

TMsQuery.Open() fires:

Code: Select all

TDataSource.OnDataChange
TDataSource.OnStateChange
TDataSource.OnDataChange
TDataSource.OnDataChange
TDataSource.OnDataChange

DataSet.Open() should fire:

Code: Select all

TDataSource.OnDataChange
TDataSource.OnStateChange
TDataSource.OnDataChange

I'm not sure, but I think that this problem wasn't always present in SDAC. Please check this because I'm doing intensive calculations when the selected record changes and right now they are done 3 times instead of once.

Best regards,
Crafty

Antaeus · Post by **Antaeus** » Mon 07 Apr 2008 12:20

Please, set the SendDataSetChangeEventAfterOpen global variable to False before opening a TMSQuery, and inform whether this fixed the behaviour.
This variable is declared in the MemDS unit.

crafty · Post by **crafty** » Mon 07 Apr 2008 13:46

Hello Antaeus,

Yes, with this option I get the normal behaviour (one call to OnFocusedRowChanged). Is this a temporary solution?

Regards

Antaeus · Post by **Antaeus** » Wed 09 Apr 2008 11:17

We are investigating this problem. Meanwhile you should use this solution in your applications.