1.原理
原理非常簡單：就是一個jlabel和jpanel。jlabel顯示標題文字以及標明控件當前是處于展開還是折疊狀態的圖片；而jpanel主要就一個作用——承載控件的容器。jlabel通過響應鼠標事件來控制jpanel是否顯示。這樣就可以達到折疊或展開的效果。
下面話不多說了，來一起看看詳細的示例代碼
2.代碼
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public class jshrinkablepanel extends jpanel {private jlabellabel;private stringtitle ="";private jpanelcontentpanel =null;private boolean isexpanded =true;private jlistlist =new jlist();private iconiconexpand =null;private iconiconcollapse =null;public jshrinkablepanel(string title, jpanel contentpanel) {super();this.title = title;this.contentpanel = contentpanel;initcomponents();initcomponentsstatus();initlayout();initresources();unregisterevents();registerevents();}private void initcomponents() {this.label =new jlabel();}private void initcomponentsstatus() {this.label.sethorizontalalignment(jlabel.left);this.label.setverticalalignment(jlabel.center);this.label.setverticaltextposition(jlabel.center);this.label.setbackground(this.list.getselectionbackground());this.iconexpand =new imageicon("src/resources/expand.png");this.iconcollapse =new imageicon("src/resources/collapse.png");}private void initlayout() {this.setlayout(new gridbaglayout());this.add(this.label,new gridbagconstraints(0,0,1,1,1,0, gridbagconstraints.west, gridbagconstraints.horizontal,new insets(0,0,0,0),0,0));this.add(this.contentpanel,new gridbagconstraints(0,1,1,1,1,0, gridbagconstraints.west, gridbagconstraints.horizontal,new insets(0,0,0,0),0,0));}private void initresources() {this.label.seticon(this.iconexpand);this.label.settext(this.title);}private void unregisterevents() {this.label.removemouselistener(this.mouselistener);}private void registerevents() {this.label.addmouselistener(this.mouselistener);}private mouselistenermouselistener =new mouseadapter() {@overridepublic void mouseclicked(mouseevent e) {isexpanded = !isexpanded;panelvisible();}@overridepublic void mouseentered(mouseevent e) {label.setopaque(true);label.repaint();}@overridepublic void mouseexited(mouseevent e) {label.setopaque(false);label.repaint();}};private void panelvisible() {this.contentpanel.setvisible(this.isexpanded);this.label.seticon(this.isexpanded ?this.iconexpand :this.iconcollapse);}public static void main(string[] args) {jframe jf =new jframe("jshrinkablepanel");jf.setbounds(400,200,400,300);jf.setdefaultcloseoperation(jframe.exit_on_close);jpanel panel=new jpanel();panel.add(new jbutton("just for show"));panel.setborder(borderfactory.createtitledborder("border"));jshrinkablepanel scrollpane=new jshrinkablepanel("testjshrinkablepanel",panel);jf.add(scrollpane);jf.setvisible(true);}} |
3.效果
panel展開鼠標在標題label上
panel展開鼠標沒在標題label上
panel折疊鼠標在標題label上
panel折疊鼠標沒在標題label上
總結
以上就是這篇文章的全部內容了，希望本文的內容對大家的學習或者工作具有一定的參考學習價值，如果有疑問大家可以留言交流，謝謝大家對服務器之家的支持。
原文鏈接：https://www.jianshu.com/p/e96bd21e0fa9
