Make Login & Register Button clickable on Navigation Drawer - Android

Question

I am developing and android application that offers user registration and login. In the Navigation Drawer I put two TextViews for Login and Register. But, Where ever I put the OnClickListener for these TextViews it gives an error:

Attempt to invoke virtual method 'void android.view.View.setOnClickListener(android.view.View$OnClickListener)' on a null object reference

please check this image, The TextViews are on the top of navigation drawer

Help. Thank You

Edited- Code

 @Override
    public boolean onCreateOptionsMenu(Menu menu) {

       // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.home, menu);
        child=menu.findItem(R.id.action_cart).getActionView();
        count_tv=(TextView)child.findViewById(R.id.cart_count_tv);

        g=Globals.getInstance();


        NavigationView navigationView=
        (NavigationView)findViewById(R.id.nav_view);
        View headerView=navigationView.getHeaderView(0);

        TextView username=(TextView)findViewById(R.id.usernameNavBar);
        TextView email=(TextView)findViewById(R.id.emailNavBar);

        withLogin=(FrameLayout)findViewById(R.id.login_frame_layout);
        wdoutLogin=(LinearLayout)findViewById(R.id.not_login_frame_layout);


        if(g.loginstatus==true) {
            withLogin.setVisibility(View.VISIBLE);
            username.setText("name");
            email.setText("email");
        }else {

            wdoutLogin.setVisibility(View.VISIBLE);
        }


                login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(HomeActivity.this, "Login button pressed", Toast.LENGTH_SHORT).show();
            }
        });
}

Possible duplicate of [What is a NullPointerException, and how do I fix it?](https://stackoverflow.com/questions/218384/what-is-a-nullpointerexception-and-how-do-i-fix-it) — John Joe, Sep 25 '17 at 08:15
post your navigation drawer and textview initialization code — Nilesh Deokar, Sep 25 '17 at 08:15
I believe there can be two possibility: 1. either you are not calling findViewById() 2. you are calling it with wrong id. But to pin point we need to see the code. — adnaan.zohran, Sep 25 '17 at 08:16
The reason i think if this error is due to where i am putting the OnClickListener. Can someone tell where to define OnClickListener for these elements? — ezzah khawar, Sep 25 '17 at 08:22
where is findviewbyid of login on which you are applying onclick? — Vidhi Dave, Sep 25 '17 at 08:35

Vidhi Dave · Accepted Answer · 2017-09-25T08:36:18.617

1

Try this:

 NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);

 headerView = navigationView.getHeaderView(0);

 tvLogin = (Textview) headerView.findViewById(R.id.login_textview_id);

Using headerView you have to cast your TextView. Then apply on click listner on textview.

edited Sep 25 '17 at 08:36

answered Sep 25 '17 at 08:17

Vidhi Dave

5,614
2
33
55

Thanks a lot. This is the answer i was looking for. Works for me! – ezzah khawar Sep 25 '17 at 10:27

Tomin B Azhakathu · Answer 2 · 2017-09-25T08:27:12.343

NavigationView navigationView = (NavigationView)findViewById(R.id.nav_view);

View header=navigationView. findViewById(R.id.header);                           
view=navigationView.inflateHeaderView(R.layout.nav_header_main);*/
login = (TextView)header.findViewById(R.id.login);
register = (TextView)header.findViewById(R.id.register);
login.setOnClickListener(this);
register.setOnClickListener(this);

you should inflate the header view and using that view you have to cast your TextView. Hope this may solve your problem.

You didnt cast the TextView or called by id. so the the Suystem cant find something with a name login

Make Login & Register Button clickable on Navigation Drawer - Android

2 Answers2