部分引用来自：https://www.runoob.com/android/android-hello-world-example.html @ReStr0(restr0)编写此文,转载请注明

程序结构

  1.  —java  存放功能代码<br />main--|<br />            —res 存放资源文件<br />![image.png](https://cdn.nlark.com/yuque/0/2022/png/22339614/1646038338512-fb625399-8b26-45c3-95c6-b208f6190518.png#clientId=u58e7499e-7dff-4&from=paste&id=u2d0581eb&margin=%5Bobject%20Object%5D&name=image.png&originHeight=720&originWidth=1280&originalType=url&ratio=1&size=284695&status=done&style=none&taskId=u47cc6751-1155-4dec-87d3-a220ef8c069)<br />![image.png](https://cdn.nlark.com/yuque/0/2022/png/22339614/1646038351867-04e048e0-bc1b-4ca7-ba1f-d98223fa7735.png#clientId=u58e7499e-7dff-4&from=paste&height=337&id=u91d436d8&margin=%5Bobject%20Object%5D&name=image.png&originHeight=337&originWidth=835&originalType=binary&ratio=1&size=38984&status=done&style=none&taskId=u25caa382-62a2-4c14-83f3-c8a569f1eae&width=835)

调用布局资源的方式

1.再Activity的onCreat()中使用