Java如何实现可折叠Panel方法示例

1.原理

原理非常简单：就是一个jlabel和jpanel。jlabel显示标题文字以及标明控件当前是处于展开还是折叠状态的图片；而jpanel主要就一个作用——承载控件的容器。jlabel通过响应鼠标事件来控制jpanel是否显示。这样就可以达到折叠或展开的效果。

下面话不多说了，来一起看看详细的示例代码

2.代码

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() {
@override
public void mouseclicked(mouseevent e) {
isexpanded = !isexpanded;
panelvisible();
}

@override
public void mouseentered(mouseevent e) {
label.setopaque(true);
label.repaint();
}

@override
public 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展开鼠标在标题label上

panel展开鼠标没在标题label上

panel折叠鼠标在标题label上

panel折叠鼠标没在标题label上

总结

以上就是这篇文章的全部内容了，希望本文的内容对大家的学习或者工作具有一定的参考学习价值，如果有疑问大家可以留言交流，谢谢大家对的支持。