Extjs has encapsulated the Panel for us. The Panel has a unified title header, panel body, panel bottom, and can also freely add toolbars, etc. In addition, there are rich layouts in extjs, which can be used to layout Panels. This method is very similar to Java's Swing. Panels can be nested and can be used as the frame of the entire page or as a small functional area. The FormPanel used in the previous articles is inherited from the Panel class.
The following example shows a relatively complete Panel, mainly setting up the toolbar: