如何在Interface Builder的“库”窗口中将项目添加到“用户媒体”类别？

The "Library" window in Interface Builder provides a "Media" tab that lists various images and sound resources that you can refer to from your nib file. There is a "System Media" item that lists default images provided by OS X, and if your nib is part of an Xcode project, you can also browse through images/sounds included in your Xcode project.The "Library" window in Interface Builder provi