public?class?layout8?extends?AppCompatActivity?implements?AdapterView.OnItemSelectedListener?{
????private?TextView?tv7;
????private?Spinner?sp;
????private?ArrayAdapter?adapter;
????private?List<String>?list=new?ArrayList<String>();
????@Override
????protected?void?onCreate(@Nullable?Bundle?savedInstanceState)?{
????????super.onCreate(savedInstanceState);
????????setContentView(R.layout.layout7);
????????sp=?(Spinner)?findViewById(R.id.spinner_1);
????????tv7=?(TextView)?findViewById(R.id.textview_7);
????????adapter=new?ArrayAdapter<String>(this,R.layout.support_simple_spinner_dropdown_item,list);
????????adapter.setDropDownViewResource(R.layout.support_simple_spinner_dropdown_item);
????????sp.setAdapter(adapter);
????????list.add("北京");
????????list.add("上海");
????????sp.setOnItemSelectedListener(this);
????}

????@Override
????public?void?onItemSelected(AdapterView<?>?adapterView,?View?view,?int?i,?long?l)?{
????????String?city=(String)?adapter.getItem(i);
????????tv7.setText(city);
????}

????@Override
????public?void?onNothingSelected(AdapterView<?>?adapterView)?{

????}
}