How to make 2 menus in navigation drawer

Question

I want to make a navigation drawer that is a side menu (it appears when you slide to the right) where you click on a button and another menu pops up instead of it in the same side field. I use setOnClickListener() on a button from the main menu (which is a Fragment1) for the second menu (which is a Fragment2) to pop up. The code compiles but the app crashes at the start.

How to fix it? Maybe there is another way to make this menu?

override fun onCreate(savedInstanceState: Bundle?)
    {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        loadF1(Frag1())
        button1.setOnClickListener()
        {
            loadF2(Frag2())
        }
    }

Edit:

stack trace

com.example.test0 E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.test0, PID: 4903
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.test0/com.example.test0.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2817)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2892)
        at android.app.ActivityThread.-wrap11(Unknown Source:0)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1593)
        at android.os.Handler.dispatchMessage(Handler.java:105)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6541)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
        at com.example.test0.MainActivity.onCreate(MainActivity.kt:19)
        at android.app.Activity.performCreate(Activity.java:6975)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1213)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2770)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2892) 
        at android.app.ActivityThread.-wrap11(Unknown Source:0) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1593) 
        at android.os.Handler.dispatchMessage(Handler.java:105) 
        at android.os.Looper.loop(Looper.java:164) 
        at android.app.ActivityThread.main(ActivityThread.java:6541) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)

consider looking at some of these : https://stackoverflow.com/questions/23353173/unfortunately-myapp-has-stopped-how-can-i-solve-this/57182205#57182205 — a_local_nobody, Jul 24 '19 at 15:53

score 1 · Answer 1 · answered Jul 25 '19 at 12:24

use group and item like this :

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <group android:checkableBehavior="single">
        <item
            android:id="@+id/nav_home"
            android:icon="@drawable/ic_home_black_24dp"
            android:title="@string/nav_home" />
        <item
            android:id="@+id/nav_photos"
            android:icon="@drawable/ic_photo_library_black_24dp"
            android:title="@string/nav_photos" />
        <item
            android:id="@+id/nav_movies"
            android:icon="@drawable/ic_local_movies_black_24dp"
            android:title="@string/nav_movies" />

        <item
            android:id="@+id/nav_notifications"
            android:icon="@drawable/ic_notifications_black_24dp"
            android:title="@string/nav_notifications" />

        <item
            android:id="@+id/nav_settings"
            android:icon="@drawable/ic_settings_black_24dp"
            android:title="@string/nav_settings" />
    </group>

    <item android:title="Other">
        <menu>
            <item
                android:id="@+id/nav_about_us"
                android:title="@string/nav_about_us" />
            <item
                android:id="@+id/nav_privacy_policy"
                android:title="@string/privacy_policy" />
        </menu>
    </item>

</menu>

And handle visibility using diff. xml

Have a look at this one : https://www.androidhive.info/2013/11/android-sliding-menu-using-navigation-drawer/

How to make 2 menus in navigation drawer

1 Answers1