Android编程之桌面小部件AppWidgetProvider用法示例

public class ExampleAppWidgetConfigure extends Activity {  static final String TAG = "ExampleAppWidgetConfigure";  // 保存的文件名  private static final String PREFS_NAME = "com.example.android.apis.appwidget.ExampleAppWidgetProvider";  // 保存的字段KEY  private static final String PREF_PREFIX_KEY = "prefix_";  // 小部件 对应ID  int mAppWidgetId = AppWidgetManager.INVALID_APPWIDGET_ID;  // 输入框  EditText mAppWidgetPrefix;  public ExampleAppWidgetConfigure() {    super();  }  @Override  public void onCreate(Bundle icicle) {    super.onCreate(icicle);    setResult(RESULT_CANCELED);    // 设置布局    setContentView(R.layout.appwidget_configure);    mAppWidgetPrefix = (EditText) findViewById(R.id.appwidget_prefix);    // 设置监听    findViewById(R.id.save_button).setOnClickListener(mOnClickListener);    // 获取intent传递过来的数据    Intent intent = getIntent();    Bundle extras = intent.getExtras();    if (extras != null) {      mAppWidgetId = extras.getInt(AppWidgetManager.EXTRA_APPWIDGET_ID,          AppWidgetManager.INVALID_APPWIDGET_ID);    }    if (mAppWidgetId == AppWidgetManager.INVALID_APPWIDGET_ID) {      finish();    }    mAppWidgetPrefix.setText(loadTitlePref(ExampleAppWidgetConfigure.this,        mAppWidgetId));  }  View.OnClickListener mOnClickListener = new View.OnClickListener() {    public void onClick(View v) {      final Context context = ExampleAppWidgetConfigure.this;      String titlePrefix = mAppWidgetPrefix.getText().toString();      //保存到SharedPreferences文件      saveTitlePref(context, mAppWidgetId, titlePrefix);      AppWidgetManager appWidgetManager = AppWidgetManager          .getInstance(context);      //更新小部件      ExampleAppWidgetProvider.updateAppWidget(context, appWidgetManager,          mAppWidgetId, titlePrefix);      Intent resultValue = new Intent();      resultValue.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID,          mAppWidgetId);      setResult(RESULT_OK, resultValue);      finish();    }  };  static void saveTitlePref(Context context, int appWidgetId, String text) {    SharedPreferences.Editor prefs = context.getSharedPreferences(        PREFS_NAME, 0).edit();    prefs.putString(PREF_PREFIX_KEY + appWidgetId, text);    prefs.commit();  }  static String loadTitlePref(Context context, int appWidgetId) {    SharedPreferences prefs = context.getSharedPreferences(PREFS_NAME, 0);    String prefix = prefs.getString(PREF_PREFIX_KEY + appWidgetId, null);    if (prefix != null) {      return prefix;    } else {      return context.getString(R.string.appwidget_prefix_default);    }  }  static void deleteTitlePref(Context context, int appWidgetId) {  }  static void loadAllTitlePrefs(Context context,      ArrayList<Integer> appWidgetIds, ArrayList<String> texts) {  }}