开启idea下方边框
https://www.jetbrains.com/help/idea/2019.2/using-code-editor.html?utm_source=product&utm_medium=link&utm_campaign=IU&utm_content=2019.2#editor_basic_usage
![在这里插入图片描述](https://img-blog.csdnimg.cn/20210224100412179.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MTk1NTMyNw==,size_16,color_FFFFFF,t_70)
![在这里插入图片描述](https://img-blog.csdnimg.cn/20210224100224714.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MTk1NTMyNw==,size_16,color_FFFFFF,t_70)
类结构图
快捷键ctrl+shift+alt+u 或者ctrl+shift+alt+s
也可以设置
![在这里插入图片描述](https://img-blog.csdnimg.cn/20200912134125709.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MTk1NTMyNw==,size_16,color_FFFFFF,t_70#pic_center)
![在这里插入图片描述](https://img-blog.csdnimg.cn/20200921164918113.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MTk1NTMyNw==,size_16,color_FFFFFF,t_70#pic_center)
全局搜索和替换
Ctrl+Shift+R
![在这里插入图片描述](https://img-blog.csdnimg.cn/20201127222955605.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MTk1NTMyNw==,size_16,color_FFFFFF,t_70)
修改鼠标停留,并显示api描述
![在这里插入图片描述](https://img-blog.csdnimg.cn/202010031655372.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MTk1NTMyNw==,size_16,color_FFFFFF,t_70#pic_center)