当您添加 multidex：真正的不要忘了做一个应用类项目，从扩展 MultiDexApplication 还是有很多坏的东西会发生

When you add the multidex:true don't forget to make an Application class in your project that extends from the MultiDexApplication or a lot of bad stuff will happen

public class YourApplication extends MultiDexApplication {
    ..........
}

和别忘了这是（该版本可能会随时间而改变，当你读到这，请确保您使用最新版本）

And don't forget this either (the version may change over time, if you read this, make sure you use the latest version)

dependencies {
    'com.android.support:multidex:1.0.1'
}