Androidr报错：Error: 'R' is not a valid file-based resource name character: File-based resource names must contain only lowercase a-z, 0-9, or underscore

报错信息：

　　D:\Exercise\Android_text\Andriod_Practice\app\src\main\res\drawable\firstpagedailyRecommended2.png: Error: 'R' is not a valid file-based resource name character: File-based resource names must contain only lowercase a-z, 0-9, or underscore

主要的报错信息：

　　Error: 'R' is not a valid file-based resource name character: File-based resource names must contain only lowercase a-z, 0-9, or underscore

报错原因：

　　drawable文件中包含了大写字母的文件

解决方法：修改文件名，即可