很抱歉让你感到困惑。在4.0中，框选的方式已经改变。要保持框选，先拖动，然后短暂停顿，再松开鼠标按钮:
摄影表视图 - Spine用户指南: 框选

供您参考，从4.1版本开始，这种操作可以通过脊柱设置在新方法和旧方法之间进行切换。

Sorry for the confusion. In 4.0, the way to box select has changed. To keep the box selection, drag then pause briefly before releasing the mouse button:
摄影表视图 - Spine用户指南: 框选

For your information, this operation can be switched between the new way and the old way via the Spine settings since 4.1.