Intent object showing error Android

Question

I am working with android activities , and trying to launch an activity when a button is clicked on the previous activity, the problem start in intent object, because the first parameter i.e; context parameter of intent constructor doesn't work with "this, MainActivity.this, getApplicationContext(),getBaseContext" i tried all of the parameters in the first parameter of the intent constructor object. Below is my code.

package com.example.nadeemahmad.guitest;


import android.content.Intent;
import android.support.annotation.IdRes;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.RelativeLayout;


public class MainActivity extends AppCompatActivity {
    Button ma_sub_btn,prof_sub_btn;
    RelativeLayout ma_rel_lay2,ma_rel_lay3,ma_dots_ly;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ma_sub_btn = (Button)findViewById(R.id.ma_sub_btn);
        ma_rel_lay2 = (RelativeLayout)findViewById(R.id.ma_rel_lay2);
        ma_rel_lay3 = (RelativeLayout)findViewById(R.id.ma_rel_lay3);
        ma_dots_ly = (RelativeLayout)findViewById(R.id.ma_dots_ly);

        ma_sub_btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                ma_rel_lay2.setVisibility(View.GONE);
                ma_rel_lay3.setVisibility(View.VISIBLE);
                ma_dots_ly.setVisibility(View.GONE);
            }
        });

        prof_sub_btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent i = new Intent(this, profile.class);
                startActivity(i);
            }
        });


    }




}

Image

the crash logcat , where you see what happend aka "android monitor" at the bottom of android studio — yanivtwin, Jul 04 '17 at 15:26
Update your code in your question, Now also it's crashing..? — Muthukrishnan Rajendran, Jul 04 '17 at 15:29
If still crashing, check your manifest file, that you register **profile** activity — Muthukrishnan Rajendran, Jul 04 '17 at 15:31

score 2 · Accepted Answer · answered Jul 04 '17 at 15:38

2

You are getting NullPointerException for Button prof_sub_btn. The problem is you have not initialized Button prof_sub_btn before setting OnClickListener to it..

Try this:

prof_sub_btn = (Button) findViewById(R.id.prof_sub_btn);
prof_sub_btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent i = new Intent(MainActivity.this, profile.class);
            startActivity(i);
        }
    });

answered Jul 04 '17 at 15:38

Ferdous Ahamed

21,438
5
52
61

OMG ! Thanks, i didn't do that – Kode Gylaxy Jul 04 '17 at 15:40
1

@Kode Gylaxy did you read my comment, I asked you long back did you initialized, anyway you solved your problem (Y). – Muthukrishnan Rajendran Jul 04 '17 at 15:41
@KodeGylaxy Most welcome dear. If my answer seems useful, then i hope you will give an upvote. Thanks in advance :) – Ferdous Ahamed Jul 04 '17 at 15:42
Thanks to you too @MuthukrishnanRajendran I was thinking that your are asking for the first line – Kode Gylaxy Jul 04 '17 at 15:42

Nilesh Deokar · Answer 2 · 2017-07-04T15:39:21.887

0

you have written this inside onClick... try writting MainActivity.this and it should work.. more on using this keyword click here

Intent i = new Intent(MainActivity.this, profile.class);

in your case after watching stacktrace ans should be to bind prof_sub_btn button with xml.

edited Jul 04 '17 at 15:39

answered Jul 04 '17 at 15:20

Nilesh Deokar

2,975
30
53

Read the question again dude – A.Edwar Jul 04 '17 at 15:24
This is what i tried and i mentioned in the question as well, by passing " MainActivity.this, getApplicationContext(),getBaseContext" crashes my app and stop it from running – Kode Gylaxy Jul 04 '17 at 15:25
`Intent i = new Intent(this, profile.class);` this line would never work since it is inside onClick. all you need to do is `Intent i = new Intent(MainActivity.this, profile.class);` – Nilesh Deokar Jul 04 '17 at 15:28
if still not working then please post your stack trace on which line app is terminating – Nilesh Deokar Jul 04 '17 at 15:29
Check the Image link @NileshDeokar – Kode Gylaxy Jul 04 '17 at 15:35
what is on line 36 ? – Nilesh Deokar Jul 04 '17 at 15:36
It is null pointer exception on widget.. `prof_sub_btn` you haven't done binding with xml – Nilesh Deokar Jul 04 '17 at 15:37

score 0 · Answer 3 · answered Jul 04 '17 at 15:43

0

Add this line after set content view :

prof_sub_btn = (Button)findViewById(R.id.prof_sub_btn);

answered Jul 04 '17 at 15:43

Valentin Garcia

143
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Intent object showing error Android

3 Answers3