UNDO

How do you undo an action???????????



Sorry the feature Undo does not exist in app inventor. It is best practise to take backups of your project and if you need to undo something you can upload a previous backed up project



I've just started working with AppInventor this weekend, and also quickly realized that Undo doesn't exist. But-- I quickly learned that very frequent use of "Save As" and "CheckPoint" saves a lot of frustration. They both save a picture of the project, however it does help to know the difference: with Checkpoint, you keep working on the original project; with Save As, you take up working on the new project. Getting my head around that took a bit, but now it's second nature and I find myself doing SaveAs to a new new project any time I make even little changes-- I know that I won't have to go back too far if I accidentally delete something! Usually, I update the name like TestApp_1a to TestApp_1b.

Is also a good idea to export the project to .aia files that you can archive on the computer, just in case something happens "in the cloud" that corrupts your project. I suggest that exporting to .aia should happen any time you've made significant changes to the project, in conjunction with doing SaveAs but not as frequently-- like if you feel TestApp has moved from TestApp_1g to TestApp_2a, do an export as well as a SaveAs...