I could see all activities that are in the solution on the toolbox before visual studio 2012 rtm release (rc and before), they were grouped by namespace . But in the visual studio rtm release, solution activities are not included in the toolbox.
Is there any way to add solution activities to toolbox automatically, i don’t want to add all dll files to toolbox.
In Visual Studio RTM release solution activities should still show in toolbox.
However, there are certain scenarios where solution activities cannot be shown in toolbox. These include:
-the activities are defined in assemblies which are only usable with 64-bit process (VS 2012 always runs as 32-bit process)
-the activities depend on a .net framework which the current project (that you have open in workflow designer now) cannot use. Example: the activities require .Net 4.5, but your current project targets .Net 4.0, or .Net 4.0 Client SKU.
-the activities in your solution depend on other assemblies which cannot be loaded
If those limitations don't apply it's fairly likely you're hitting a bug, you could follow up with connect.microsoft.com or contacting Microsoft Product Support.