fix 登录后不可后退

app/src/main/java/com/doverfuelingsolutions/issp/view/MainActivity.kt

@@ -1,7 +1,5 @@
 package com.doverfuelingsolutions.issp.view
 
-import android.content.Context
-import android.content.Intent
 import android.os.Bundle
 import androidx.appcompat.app.AppCompatActivity
 import androidx.lifecycle.MutableLiveData

app/src/main/res/navigation/nav_activity.xml

@@ -20,6 +20,8 @@
         android:label="@string/login">
         <action
             android:id="@+id/action_login_to_main"
-            app:destination="@id/activityMain" />
+            app:destination="@id/activityMain"
+            app:popUpTo="@id/activityMain"
+            app:popUpToInclusive="true" />
     </fragment>
 </navigation>