How to go from one fragment to another fragment in kotlin?-CodePudding

I have a button in fragment A and when I click on fragment A, I want it to be redirected to fragment B. How to achieve this in kotlin? Right now I am using this code but app crash.

btntest.setOnClickListener {
            var intent = Intent(view.context, FragmentB::class.java)
            startActivity(intent)
        }

CodePudding user response：

I'd suggest you take a look on Make sure to give an ID to each fragment (that's what you'll use to navigate between them later). Additionally, you can use app:startDestination in order to set the first fragment to be shown.

<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:android="http://schemas.android.com/apk/res/android"
    app:startDestination="@id/blankFragment">
    <fragment
        android:id="@ id/blankFragment"
        android:name="com.example.cashdog.cashdog.BlankFragment"
        android:label="@string/label_blank"
        tools:layout="@layout/fragment_blank" />
</navigation>

Then, in the activity/fragment that will be hosting the fragments, add a FragmentContainerView and set the graph to the one you created.

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <androidx.fragment.app.FragmentContainerView
        android:id="@ id/nav_host_fragment"
        android:name="androidx.navigation.fragment.NavHostFragment"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"

        app:defaultNavHost="true"
        app:navGraph="@navigation/nav_graph" />

</androidx.constraintlayout.widget.ConstraintLayout>

Finally, in order to navigate between fragments, use this in the Activity that is hosting the navigation (use getActivity() if a Fragment is hosting the navigation).

// as per defined in your FragmentContainerView
val navHostFragment = supportFragmentManager.findFragmentById(R.id.nav_host_fragment) as NavHostFragment
val navController = navHostFragment.navController

// Navigate using the IDs you defined in your Nav Graph
navController.navigate(R.id.blankFragment)

Source: https://developer.android.com/guide/navigation/navigation-getting-started

Edit: if you want to access the controller within your Fragment, use activity?.supportFragmentManager to get the fragment manager.