My answer is for Xcode 5, but should also be for Xcode 4.
In a typical Apple mod, they gave you several ways to do almost the same thing. Very confusing and annoying. There are three ways, and only one way relates to the original question:
(1) Use File → Add Files to ... The problem with this is that it will only add files to the workspace if the NO project is selected. The problem with THAT is that when you select a project, I don’t know how to cancel it.
(2) Use the “+” in the lower left corner. The problem with this, this is equivalent to using a drop down menu (# 1 above)
(3) Right-click on the left panel (in an empty area) and you will see “Add files to” This is the only right way to do this, as it ensures that the file is added to the workspace, and not any one selected project.
Try all three methods after selecting an existing project and you will see what I mean.
Based on my previous experience with Xcode, Apple will take about 10 years to fix such things.
Eric apRhys
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