毕设day20

bug：

今天导入别人的项目时，遇到Could not resolve all files for configuration ':app:debugCompileClasspath'.的问题：

解决方案如下：
在project级别下的build.gradle文件中的allprojiects大括号里添加一个maven库： 

buildscript {
repositories {
和

allprojects {
repositories {

maven{ url 'https://maven.aliyun.com/repository/google'}
 }

bug:

Google Play Service is missing or outdated on this device, and there is no Play Store to update it. If you are using an emulator, try again with a newer version of the system image.