[Android] Redirect Activity แล้วแต่ยังไม่สามารถเรียก event Onclick บน Activity นั้นได้

public class MainActivity extends AppCompatActivity {

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

        Intent i = new Intent(MainActivity.this, LoginActivity.class);
        startActivity(i);
    }
}

public void onClickSignIn(View view) {
        mUsernameView = (EditText) findViewById(R.id.username);
        mPasswordView = (EditText) findViewById(R.id.password);
        Log.v(TAG, "=>" + mUsernameView.getText());
}