CODEWITHSUNDEEP
androidandroid-studio
Shubham Goyal
Shubham Goyal

Reputation: 11

Android Studio App crashes on run after successful build and apk installation

This is the simple java code used by me on login screen. App closes itself after the splash screen which I applied. It doesnt go any further. what to do?

public class MainActivity extends AppCompatActivity {
EditText username = (EditText)findViewById(R.id.input_email);
EditText password = (EditText)findViewById(R.id.input_password);
Button loginButton = (Button) findViewById(R.id.btn_login);
int counter=3;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main); }

//Login Button Code

public void onBtn(View v){
if(username.getText().toString().equals("[email protected]")&&
(password.getText().toString().equals("shubham")))
{
Toast.makeText(this, "Login Success", Toast.LENGTH_LONG).show();}
else {
Toast.makeText(this, "Login Failed", Toast.LENGTH_SHORT).show();
counter--;
if(counter==0){ loginButton.setEnabled(false); }
else 
{ 
Toast.makeText(this, counter+" attempts left", Toast.LENGTH_SHORT).show(); }
}}

//Sign Up Button Code

public void linkSign(View v){
Intent intent = new Intent(this, signupActivity.class);
startActivity(intent);
}}

Upvotes: 1

Views: 2031

Answers (2)

yatin deokar
yatin deokar

Reputation: 781

You initialize EditText and Button view on wrong place ,you need to initialize it inside onCreate method like below.

public class MyActivity extends AppCompatActivity {


    EditText username;

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

        username = (EditText)findViewById(R.id.input_email);
       ...

    }


}

Upvotes: 0

Pavneet_Singh
Pavneet_Singh

Reputation: 37404

move 

EditText username = (EditText)findViewById(R.id.input_email);
EditText password = (EditText)findViewById(R.id.input_password);
Button loginButton = (Button) findViewById(R.id.btn_login);

after setContentView while keeping reference variable outside oncreate because views are only available in the UI hierarchy of the activity after invocation of setContentView

EditText username;
EditText password;
Button loginButton;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main); 
    username = (EditText)findViewById(R.id.input_email);
    password = (EditText)findViewById(R.id.input_password);
    loginButton = (Button) findViewById(R.id.btn_login);
}

Upvotes: 2

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