Question

JPanel与JFrame有什么关系 与不同的

Answer 1

JFrame是顶级容器，而JPanel是普通容器。包含Swing组件的程序必须包含一个顶级容器，而Swing组件不可以直接加入到顶级容器中。Sun文档有下列相关的解释：1、The containment hierarchy for any window or applet that contains Swing components must have a Swing top-level container at the root of the hierarchy. 2、You don 't add components directly to a top-level container such as a Jframe, and you should add components to a container (called the content pane) that is itself contained by the JFrame. 3、Swing provides three generally useful top-level container classes: JFrame, JDialog, and JApplet 至于其他的不同，它们既然是不同的类，自然不同了，可以看看API文档。