打包Android APK是发生这类错误，主要是io.flutter库没有下载下来，重新配置一下国内的资源
buildscript { ext.kotlin_version = '1.3.50'
repositories {
// google()
// jcenter()
maven { url 'http://maven.aliyun.com/nexus/content/repositories/google' }
maven { url 'http://maven.aliyun.com/nexus/content/repositories/jcenter' }
maven { url 'https://jitpack.io' }
}
}
allprojects {
repositories {
// google()
// jcenter()
maven { url 'http://maven.aliyun.com/nexus/content/repositories/google' }
maven { url 'http://maven.aliyun.com/nexus/content/repositories/jcenter' }
maven { url 'https://jitpack.io' }
maven { url "https://storage.googleapis.com/download.flutter.io" }
}//这句是为了解决io.flutter异常问题}
这样可以提高运行编译速度，也解决了io.flutter异常问题
