我正試圖創建一個類來處理存儲和檢索兩個用戶設置'radius'和'cluster'。Android SharedPreferences getSharedPreferences上的NullPointerExceptionException
加載「設置」活動時,我得到一個空指針異常。從用戶設置
段:
storage = new Persistence();
radius = (EditText) findViewById(R.id.etRadius);
radius.setText(String.valueOf(storage.getRadius())); <-- Problem
類來處理持久性:
public class Persistence extends Activity {
private static final String PREFERENCES = "tourist_guide_preferences";
private SharedPreferences settings;
private SharedPreferences.Editor editor;
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
settings = getSharedPreferences(PREFERENCES, 0);
editor = settings.edit();
}
public int getRadius()
{
return settings.getInt("radius", 2000);
}
public int getClusterSize()
{
return settings.getInt("cluster", 50);
}
public void setRadius(int radius)
{
editor.putInt("radius", radius);
editor.commit();
}
public void setClusterSize(int size)
{
editor.putInt("cluster", size);
editor.commit();
}
}
請結帳在這裏:這個最好的最好的例子http://stackoverflow.com/questions/5734721/android-shared-preferences – 2012-03-08 18:41:29