修改模式切换流程

app/src/main/java/com/sw/dualscreen/MyApp.kt

@@ -9,10 +9,12 @@ import timber.log.Timber
 class MyApp : App() {
     companion object {
         const val DEBUG: Boolean = true
+        var instance: MyApp?=null
     }
 
     override fun onCreate() {
         super.onCreate()
+        instance = this
         Timber.plant(Timber.DebugTree())
         var deviceId = AppUtil.getUDID(this)
         Timber.d("UDID = ${AppUtil.getUDID(this)}")