Toast function doesn't appear

Question

I try to make toast function but it seems that the toast function doesn't show up when i click button.. Can someone help me to solve my case please..

public void displayText (View view){

    String text = etName.getText().toString();

    tvMessage.setText("Welcome! " + text);

    Toast toast = Toast.makeText(MainActivity.this, "WELCOME", Toast.LENGTH_SHORT);
    toast.show();
}

public void showToast() {
    Toast.makeText(MainActivity.this, "Name have been reset", Toast.LENGTH_SHORT).show();
}

I try many others ways like wiping emulator but it's still doesn't work...