Question

当用户单击通知时，我需要导航到一个片段。

如果该应用正在运行，则可以正常运行。但是，当我退出该应用程序，然后单击通知时，它会崩溃并显示以下错误消息：

2020-04-24 18:06:49.607 14832-14832/com.package.name E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.package.name, PID: 14832
java.lang.IllegalStateException: no current navigation node
    at androidx.navigation.NavController.navigate(NavController.java:824)
    at androidx.navigation.NavController.navigate(NavController.java:804)
    at androidx.navigation.NavController.navigate(NavController.java:790)
    at androidx.navigation.NavController.navigate(NavController.java:985)
    at com.package.name.core.navigation.NavigationActivity.handleNewIntent(NavigationActivity.kt:358)
    at com.package.name.core.navigation.NavigationActivity.onPostCreate(NavigationActivity.kt:257)
    at android.app.Instrumentation.callActivityOnPostCreate(Instrumentation.java:1385)
    at android.app.ActivityThread.handleStartActivity(ActivityThread.java:3088)
    at android.app.servertransaction.TransactionExecutor.performLifecycleSequence(TransactionExecutor.java:180)
    at android.app.servertransaction.TransactionExecutor.cycleToPath(TransactionExecutor.java:165)
    at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:142)
    at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:70)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1906)
    at android.os.Handler.dispatchMessage(Handler.java:106)
    at android.os.Looper.loop(Looper.java:193)
    at android.app.ActivityThread.main(ActivityThread.java:6863)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:537)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)

我的导航代码：

navController.navigate(
                navigateToFragment(
                    someParam = "some value",
                    someOtherParam = "other value"
                )
            )

我的navController如何实例化

private val navController: NavController by lazy {
    Navigation.findNavController(this, R.id.nav_host_fragment)
}

我猜这是由于我的navController没有正确初始化吗？任何想法如何解决此问题/什么是正确的方法？

Answer 1

我找到了解决方法。

缺少的是为我的navcontroller设置开始目标，像这样：

  graph = navGraph.apply { startDestination = destinationId }
  currentDestination?.let { applyDestinationPropertiesToToolbar(it) }

导航至通知中的NavController片段

1 个答案: