@Override protected void onResume() { super.onResume(); final String myPackageName = getPackageName(); if (Telephony.Sms.getDefaultSmsPackage(getApplicationContext()) == null){ startActivity(new Intent(this, HomeActivity.class)); finish(); }else { if (!Telephony.Sms.getDefaultSmsPackage(getApplicationContext()).equals(myPackageName)) { // App is not default. // Show the "not currently set as the default SMS app" interface // Set up a button that allows the user to change the default SMS app Button button = findViewById(R.id.bt_set_default); button.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { Intent intent = new Intent(Telephony.Sms.Intents.ACTION_CHANGE_DEFAULT); intent.putExtra(Telephony.Sms.Intents.EXTRA_PACKAGE_NAME, myPackageName); startActivity(intent); } }); } else { // App is the default. // Hide the "not currently set as the default SMS app" interface startActivity(new Intent(this, HomeActivity.class)); finish(); } } }