Create a spinner programmatically android

问题

I want to create a spinner without using xml. I am new in android and my knowledge is limited. By now i have this code (see above) and i want my spinner in on of the tabs of my TabActivity. There is no obvious error but whene i open my activity the tab is empty. I would appreciate some help.

public class Search extends Activity {

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    ArrayList<String> spinnerArray = new ArrayList<String>();
    spinnerArray.add("one");
    spinnerArray.add("two");
    spinnerArray.add("three");
    spinnerArray.add("four");
    spinnerArray.add("five");

    Spinner spinner = new Spinner(this);
    ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_dropdown_item, spinnerArray);
    spinner.setAdapter(spinnerArrayAdapter);


}

回答1:

You need to add the Spinner to a layout.

First create a container for the Spinner and then create the Spinner and add it to your container. Next set content of you Activity to your container.

This could be done like this, in your onCreate method:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_my);

    LinearLayout layout = new LinearLayout(this);

    ArrayList<String> spinnerArray = new ArrayList<String>();
    spinnerArray.add("one");
    spinnerArray.add("two");
    spinnerArray.add("three");
    spinnerArray.add("four");
    spinnerArray.add("five");

    Spinner spinner = new Spinner(this);
    ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_dropdown_item, spinnerArray);
    spinner.setAdapter(spinnerArrayAdapter);

    layout.addView(spinner);

    setContentView(layout);
}

EDIT:

Just to clarify: if the Spinner isn't added to the content of the Activity inside a layout, it isn't visible, so that's why you don't get any errors or anything, because there isn't any errors in your code, per se ;-)

回答2:

public class MainActivity extends AppCompatActivity {

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

        // The following can also be done using a loop
        ArrayList<String> spinnerArray = new ArrayList<String>();
        spinnerArray.add("one");
        spinnerArray.add("two");
        spinnerArray.add("three");
        spinnerArray.add("four");
        spinnerArray.add("five");


        Spinner spinner = new Spinner(MainActivity.this);
        ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_spinner_dropdown_item, spinnerArray);
        spinner.setAdapter(spinnerArrayAdapter);
        layout.addView(spinner);
        setContentView(layout);
    }
    }

来源：https://stackoverflow.com/questions/16119841/create-a-spinner-programmatically-android