How to rectify a DrawersLayout?

Question

I am trying to add the navigation layout to my activity but I keep getting an error of type

Caused by java.lang.NullPointerException: Attempt to invoke virtual method 'void androidx.drawerlayout.widget.DrawerLayout.addDrawerListener(androidx.drawerlayout.widget.DrawerLayout$DrawerListener)' on a null object reference

What might be the problem of the code

package com.agile.Login;

import androidx.appcompat.app.ActionBarDrawerToggle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.core.view.GravityCompat;
import androidx.drawerlayout.widget.DrawerLayout;

import android.os.Bundle;

public class Homedashboard extends AppCompatActivity {
    private DrawerLayout drawer;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_homedashboard);

       Toolbar toolbar = findViewById(R.id.too_bar1);
       setSupportActionBar(toolbar);

        setTitle("Hazina Sacco");
        drawer =  findViewById(R.id.navigation_drawer);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(this, drawer, toolbar,
                R.string.navigation_drawer_open, R.string.navigation_drawer_close);
       drawer.addDrawerListener(toggle);
        toggle.syncState();

    }
    @Override
    public void onBackPressed() {
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }
}

<?xml version="1.0" encoding="utf-8"?>
<androidx.drawerlayout.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:fitsSystemWindows="true"
    tools:context=".Homedashboard"
    android:id="@+id/navigation_drawer"
    tools:openDrawer="start">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">
        <androidx.appcompat.widget.Toolbar
            android:layout_width="match_parent"
            android:layout_height="176dp"
            android:background="@color/colorPrimary"
            android:elevation="4dp"
            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
            />
        <FrameLayout
            android:id="@+id/fragment_container"
            android:layout_width="match_parent"
            android:layout_height="match_parent"/>
    </LinearLayout>
    <com.google.android.material.navigation.NavigationView
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        app:headerLayout="@layout/nav_header"
        app:menu="@menu/nav_menu"/>




</androidx.drawerlayout.widget.DrawerLayout>

That's should not happen according your code. Can you add your full stack trace? — Md. Asaduzzaman, Feb 04 '20 at 11:48

score 0 · Answer 1 · answered Feb 04 '20 at 11:11

0

I think your toolbar is null,

Toolbar toolbar = findViewById(R.id.too_bar1);

This line giving you a null toolbar, because there is no toolbar in your layout with id too_bar1. Please check for this.

answered Feb 04 '20 at 11:11

Nehal Godhasara

787
3
7

i have added but i still get the same problem – Tony Chirchir Feb 04 '20 at 11:35
According to your code, everything seems to be fine, can you please debug and check if your drawer variable is null or not? – Nehal Godhasara Feb 04 '20 at 12:07

How to rectify a DrawersLayout?

1 Answers1