How do I set spinner value based on the value in preferences

问题

I populate a spinner from a jsonarray and i need to set the spinner to a value stored in preferences. I want to set the spinner String "id" to be equal with "idlocatie" stored in preferences.

  SharedPreferences mySharedPreferences =PreferenceManager.getDefaultSharedPreferences(this);     
    final String locatie= mySharedPreferences.getString("idlocatie", "");
 JSONObject jsonLocatii = JSONfunctions.getJSONfromURL("http://www.mySite");
      try{      
    JSONArray  earthquakes = jsonLocatii.getJSONArray("earthquakes");

        for(int i=0;i<earthquakes.length();i++){                        
            JSONObject e = earthquakes.getJSONObject(i);                
            String id = e.getString(TAG_IDLOCATIE);
            String name = e.getString(TAG_LOCATIE);             
            locatiiList.add(new Locatii(id, name.toUpperCase()));        
            locatii = (Spinner) findViewById(R.id.spinLocatie);
            LocatiiAdapter cAdapter = new LocatiiAdapter(this, android.R.layout.simple_spinner_item, locatiiList);
            locatii.setAdapter(cAdapter);                 
        }   

 }catch(JSONException e)        {
     Log.e("log_tag", "Error parsing data "+e.toString());
 }

回答1:

if I understand it right, you're trying to set the selected value? try locatii.setSelection(cAdapter.getPosition(locatie));

Or are you trying to change an actual value associated with the selection?

EDIT: Here, try this. You'll need some sanity checking but hopefully on the right direction. Another option is to override getPosition(), and yet another is to find the index from locatiiList and use that.

SharedPreferences mySharedPreferences =PreferenceManager.getDefaultSharedPreferences(this);     
final String locatie= mySharedPreferences.getString("idlocatie", "");
JSONObject jsonLocatii = JSONfunctions.getJSONfromURL("http://www.mySite");
try {      
    JSONArray  earthquakes = jsonLocatii.getJSONArray("earthquakes");

    for(int i=0;i<earthquakes.length();i++){                        
        JSONObject e = earthquakes.getJSONObject(i);                
        String id = e.getString(TAG_IDLOCATIE);
        String name = e.getString(TAG_LOCATIE);             
        locatiiList.add(new Locatii(id, name.toUpperCase()));        
    }   
// Move these out of the for loop.
    locatii = (Spinner) findViewById(R.id.spinLocatie);
    LocatiiAdapter cAdapter = new LocatiiAdapter(this, android.R.layout.simple_spinner_item, locatiiList);
    locatii.setAdapter(cAdapter);                 

 } catch(JSONException e) {
     Log.e("log_tag", "Error parsing data "+e.toString());
 }

locatii.setSelection(getIndex(locatii, locatie));

private int getIndex(Spinner spinner, String myString) {
    for (int i=0;i<spinner.getCount();i++){
        if (spinner.getItemAtPosition(i).toString().equalsIgnoreCase(myString)){
            return i;
        }
    }
    // Check for this when you set the position.
    return -1;
}

来源：https://stackoverflow.com/questions/25632549/how-do-i-set-spinner-value-based-on-the-value-in-preferences

标签

android

json

spinner