for example, when i drap a rmvb file onto smplayer’s window tab on the task manager(taskbar), it is expected that the smplayer should be activated and then i can drop the file into its window and play it. but it didn’t be activated.
the same thing happens to konqueror.
when drap a mp3 file, the same thing happens to amarok.
so i think its not related to dolphin nor smplayer.
i think its related to KDE. it seems work well before i upgrated KDE from 4.8.5 to 4.9.3, but i dont remember well exactly.
The problem with Drag & Drop not working in KDE 4.9 is a reported bug I see with KDE version 4.9.2 and in one case a user had to enable Desktop Search for this function to work again in KDE version 4.9.3 (go to menu/Configure Desktop/Workspace Appearance and Behavior/Desktop Search). KDE 4.8 is still the official Release in openSUSE 12.2 (though I see mention KDE 4.9 will be moved to Tumbleweed) which just means KDE 4.9 does not have official support yet in openSUSE 12.2 mainline. I find that Drag & Drop works as intended in KDE 4.8 which I am using in openSUSE 12.2.
If you update your Desktop version above the official released version, most often you must report any problems directly with the organization that released that application. You can search for existing and/or report new bugs for the KDE desktop here: https://bugs.kde.org/ . I would try enabling the KDE Desktop Search to see if that helps. If you have any success with this problem or make a new bug report, please post a message of your success or a bug report URL back here for us to see. Good Luck with your KDE Desktop version 4.9.3 **Drag & Drop **problem.
Consider that doing a KDE desktop downgrade is not exactly supported and just because one function does not work like Drag & Drop it may not be worth the risk to reload openSUSE over again if the KDE downgrade does not work. Normally I suggest you go into YaST, switch to patterns and make sure you have a backup desktop loaded so you can use it to fix any problems. In the login menu, try to select a different desktop and make sure it works.
To switch back to KDE 4.8 from 4.9, remove the 4.9 repositories that you added in YaST / Software / Software Repositories. Next, add back in the 4.8 ones you can find here:
After the repository switch then go to YaST / Software / Software Manager, after adding in these new repositories shown above, select the repository view mode (Top Left button for View and then Repositories), select the core name you used, then select Switch to this repository. Do the same for the second repository for Extra using the name you provided. I suggest you do a restart of openSUSE after the old KDE desktop is reloaded by YaST. Upon login, select the KDE desktop again as the switch may have forgotten the previous default. If there is no default, you log in, but just find you are back at the login and nothing happens. This means there is no default desktop selected.
Always make a backup of your data and consider that if the switch back does not work, you may need to reload openSUSE 12.2. Use your backup Desktop to get back online if you need to. If these instructions make no sense, ask more questions and get a good backup of your data before you go forward with attempts to change the KDE Desktop version.