title: How can I change the location of files in xcode project?
body: <p>I put some files on the same level of <code>*.xcodeproj</code> file carelessly. When I move these files into the right location in Finder， Xcode  tells me that these files are missing. So I delete the group which contains these files whose names have been read (I realize it is a mistake). And I drag these files from Finder into the xcode to build a new group. But when I try to run the project, Xcode still can't find these code. How can I solve the problem?  </p>