The first thing you should do is move the iPhoto library out of the trash and put it on your desktop so you don't accidentally delete it. And close iPhoto if you have it open.
When you said, "dragged the folder from trash back into iphoto" by that did you mean that you dropped it onto the open iPhoto window?
Now... is it your entire iPhoto library folder that you have in your trash?
When you open the Finder and look in your Pictures Folder (in the side bar) is there an "iPhoto library" folder in there as well.
If there is, rename it. Just add the word "bad" to the name or something like that. (Make sure iPhoto is not running before you do that). Now put the iPhoto Library that you first moved to the trash into the Pictures Folder. Make sure that it is named "iPhoto Library", and move the "Bad" library to the desktop.
Try opening iPhoto now and see if everything is OK. If it is, you can move the "Bad" library to the trash and delete it.
If it isn't back to normal, post here again and let us know. And don't delete anything.
bd
When you said, "dragged the folder from trash back into iphoto" by that did you mean that you dropped it onto the open iPhoto window?
Now... is it your entire iPhoto library folder that you have in your trash?
When you open the Finder and look in your Pictures Folder (in the side bar) is there an "iPhoto library" folder in there as well.
If there is, rename it. Just add the word "bad" to the name or something like that. (Make sure iPhoto is not running before you do that). Now put the iPhoto Library that you first moved to the trash into the Pictures Folder. Make sure that it is named "iPhoto Library", and move the "Bad" library to the desktop.
Try opening iPhoto now and see if everything is OK. If it is, you can move the "Bad" library to the trash and delete it.
If it isn't back to normal, post here again and let us know. And don't delete anything.
bd