want to use check box in the alert dialog box in android

Question

I want to open alert dialog box from menu and in alert dialog box I want check boxes so that user can select the items but I am getting null pointer exception.

         public class MainActivity extends AppCompatActivity
            implements NavigationView.OnNavigationItemSelectedListener {
        AlertDialog.Builder favourite_box;
        CheckBox googlenews,toi,ie,ht

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
            setSupportActionBar(toolbar);

            Initialise_obj();
            checkbox_obj();
        }


        private void checkbox_obj() {
            googlenews=(CheckBox)findViewById(R.id.checkBox1);
            toi=(CheckBox)findViewById(R.id.checkBox2);
            ie=(CheckBox)findViewById(R.id.checkBox3);
            ht=(CheckBox)findViewById(R.id.checkBox4);

        }

        @Override
        public boolean onCreateOptionsMenu(Menu menu) {
            // Inflate the menu; this adds items to the action bar if it is present.
            getMenuInflater().inflate(R.menu.main, menu);
            return true;
        }

        @Override
        public boolean onOptionsItemSelected(MenuItem item) {
            // Handle action bar item clicks here. The action bar will
            // automatically handle clicks on the Home/Up button, so long
            // as you specify a parent activity in AndroidManifest.xml.
            int id = item.getItemId();

            if (id == R.id.action_fav_list) {
                LayoutInflater inflater = this.getLayoutInflater();
                View dialogView = inflater.inflate(R.layout.favourite_dialog, null);

                favourite_box = new AlertDialog.Builder(this);
                favourite_box.setView(dialogView);
                //   historyBox.setMessage("message to be display in alert box");
                favourite_box.setPositiveButton("Done", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {


                        if(googlenews.isChecked()){
                            Toast.makeText(getApplicationContext(),"haha",Toast.LENGTH_SHORT).show();
                        } if(toi.isChecked()){
                           Toast.makeText(getApplicationContext(),"done",Toast.LENGTH_SHORT).show();
                        } if(ie.isChecked()){
                            Toast.makeText(getApplicationContext(),"completed",Toast.LENGTH_SHORT).show();
                        } if(ht.isChecked()){
    Toast.makeText(getApplicationContext(),"success",Toast.LENGTH_SHORT).show();
                        } 

                        dialog.cancel();
                    }
                });
                favourite_box.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.cancel();
                    }
                });

                final AlertDialog alert=favourite_box.create();
                alert.setTitle("Favourite");
                alert.show();

            }

            return super.onOptionsItemSelected(item);
        }


    }

E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.kishan.bulletin, PID: 24928 java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.widget.CheckBox.isChecked()' on a null object reference at com.example.kishan.bulletin.MainActivity$2$override.onClick(MainActivity.java:206) at com.example.kishan.bulletin.MainActivity$2$override.access$dispatch(MainActivity.java) at com.example.kishan.bulletin.MainActivity$2.onClick(MainActivity.java:0) at android.support.v7.app.AlertController$ButtonHandler.handleMessage(AlertController.java:157) at android.os.Handler.dispatchMessage(Handler.java:111) at android.os.Looper.loop(Looper.java:207) at android.app.ActivityThread.main(ActivityThread.java:5769) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:679)

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) — takendarkk, Aug 03 '17 at 21:46
Where are your check boxes? in your main activity layout or the layout of dialog? — SripadRaj, Aug 04 '17 at 06:04

score 0 · Answer 1 · answered Aug 07 '17 at 05:34

Dont call your checkbox_obj() method in onCreate(). Remove the method call from onCreate() and delete the method checkbox_obj().

You have to get the check box views from the dialog layout. You have to do like below. I have put the checkboxes initialization in your onOptionsItemSelected()

 @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        if (id == R.id.action_fav_list) {
            LayoutInflater inflater = this.getLayoutInflater();
            View dialogView = inflater.inflate(R.layout.favourite_dialog, null);

            favourite_box = new AlertDialog.Builder(this);
            favourite_box.setView(dialogView);

            // your check boxes should be inflated here.                
            googlenews=(CheckBox)dialogView.findViewById(R.id.checkBox1);
            toi=(CheckBox)dialogView.findViewById(R.id.checkBox2);
            ie=(CheckBox)dialogView.findViewById(R.id.checkBox3);
            ht=(CheckBox)dialogView.findViewById(R.id.checkBox4);


            //   historyBox.setMessage("message to be display in alert box");
            favourite_box.setPositiveButton("Done", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                        // rest of your code.
                }

            }

    }

want to use check box in the alert dialog box in android

1 Answers1