Dear all, for no data source in VS2012 of telerik
Thank you for Negin , your method is working
1- Go to: "Tools" -> "Choose Toolbox Items"
[Note: you can`t see "Choose Toolbox Items" in "Tools" menu if your VS is set to certain development settings. but you should see it if your VS is set to "General Development Settings", however if you want to reset your VS to "General Development Settings" follow these steps
1- Go to: "Tools" -> "Import and Export Settings".
2- Choose "Reset all settings" and click "Next".
3- Choose the way you want VS to save your current settings. Consider that after VS resets you will loose all of your settings
so it is recommended that you create a backup of your current settings to export in VS later. Click "Next".
4- Choose "General Development Settings" and click "Finish".
5- Restart VS.
2- Choose " .Net Framework Components" tab.
3- Check all items related to Telerik assembly. [To do this you can sort the items by "Assembly Name"].
****For the filter blank area , you can write down " Telerik " and all related Telerik would be filtered and show on display
and then tick all of them and press "OK"
4- Restart VS. by restart your computer
I hope it will works for you guys