如何更改我的 Spinner 使用的字符串数组？

Question

I'm trying to change the contents of my two Spinners. So I've got my Spinners created:

       Spinner spinner01 = (Spinner) findViewById(R.id.Spinner01);
    Spinner spinner02 = (Spinner) findViewById(R.id.Spinner02);
    ArrayAdapter<CharSequence> adapter1 = ArrayAdapter.createFromResource(
            this, R.array.MetricUnitsArray, android.R.layout.simple_spinner_item);
    ArrayAdapter<CharSequence> adapter2 = ArrayAdapter.createFromResource(
            this, R.array.MetricUnitsArray, android.R.layout.simple_spinner_item);


    adapter1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    adapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    spinner01.setAdapter(adapter1);
    spinner02.setAdapter(adapter2);

    spinner01.setOnItemSelectedListener(new MyOnItemSelectedListener1());
    spinner02.setOnItemSelectedListener(new MyOnItemSelectedListener2());

Now from a different method, I want to be able to do something like this:

    adapter1 = ArrayAdapter.createFromResource(
            this, R.array.ImperialUnitsArray, android.R.layout.simple_spinner_item);
    adapter2 = ArrayAdapter.createFromResource(
            this, R.array.ImperialUnitsArray, android.R.layout.simple_spinner_item);

Is there anyway to get the adapters to read from a different String Array? Or should I be replacing the values in the String Array with new ones?

Answer 1

Create separate adapters for each array you wish to assign to spinner2. Declare them as final. Place the adapter declarations before you set spinner1 ItemSelected Listener. In spinner1 ItemSelected listener, set the appropriate adapter as needed.

In the code below I have two spinners. spinner1 has 4 entries containing sensor types, when one of the sensor types is selected spinner2 is then populated with the various models for that sensor type.

public class MainActivity extends Activity {

void showToast(CharSequence msg) {
    Toast.makeText(this, msg, Toast.LENGTH_SHORT).show();
}

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

   final Spinner s1 = (Spinner) findViewById(R.id.spinner_sensor_type);
   final Spinner s2 = (Spinner) findViewById(R.id.spinner_sensor_model);
   final ArrayAdapter<CharSequence> sensor_adapter = ArrayAdapter.createFromResource(
            this, R.array.sensors,android.R.layout.simple_spinner_item);
    sensor_adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    final ArrayAdapter<CharSequence> pa_adapter = ArrayAdapter.createFromResource(
            this, R.array.pa_models,android.R.layout.simple_spinner_item);
    final ArrayAdapter<CharSequence> ca_adapter = ArrayAdapter.createFromResource(
            this, R.array.ca_models,android.R.layout.simple_spinner_item);
    final ArrayAdapter<CharSequence> ni_adapter = ArrayAdapter.createFromResource(
            this, R.array.ni_models,android.R.layout.simple_spinner_item);
    final ArrayAdapter<CharSequence> ni_fe_adapter = ArrayAdapter.createFromResource(
            this, R.array.ni_fe_models,android.R.layout.simple_spinner_item);
    pa_adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    ca_adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    ni_adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    ni_fe_adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    s1.setAdapter(sensor_adapter); 
    s2.setAdapter(pa_adapter); // set default array values in spinner 2 
    s1.setOnItemSelectedListener(
            new OnItemSelectedListener() {
                public void onItemSelected(
                        AdapterView<?> parent, View view, int position, long id) {
                    showToast("Sensor Type: position=" + position + " id=" + id);
                    switch (position) {
                    case 0: 
                        s2.setAdapter(pa_adapter);                          
                            break;
                    case 1: 
                        s2.setAdapter(ca_adapter);
                            break;
                    case 2:
                        s2.setAdapter(ni_adapter);
                            break;
                    case 3:
                        s2.setAdapter(ni_fe_adapter);
                    default: // Do this...
                            break;
               }  

                }

                public void onNothingSelected(AdapterView<?> parent) {
                    showToast("Sensor Type: unselected");
                }
            });



    s2.setOnItemSelectedListener(
            new OnItemSelectedListener() {
                public void onItemSelected(
                        AdapterView<?> parent, View view, int position, long id) {
                    showToast("Sensor Model: position=" + position + " id=" + id);
                }

                public void onNothingSelected(AdapterView<?> parent) {
                    showToast("Sensor Model: unselected");
                }
            });
}

}

Answer 2

You can use the ArrayAdapter 's getters/setters:

Eg:

adapter1.clear();
adapter1.addAll(theNewListOfValues);
adapter1.notifyDatasetChanged();

Answer 3

You should be able to just call setAdapter on your spinners with the new adapters. I would suggest storing the adapters as fields in your activity after you create them so you can easily re-use them if you need to swap between the adapters again.