public class StudentInfo extends Fragment{ // Fragment對應的標籤，當Fragment依附於Activity時得到 private String tag; @Override public void onAttach(Activity activity) { super.onAttach(activity); tag = getTag(); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { TextView textView = new TextView(getActivity()); textView.setText(tag); return textView; }}
在strings.xml中定義一個數組,這個數組就是菜單項的信息:
<?xml version="1.0" encoding="utf-8"?><resources> <string name="app_name">ActionBar下拉菜單</string> <string-array name="student"> <item>鄧名僑</item> <item>劉天喜</item> <item>其黃石</item> <item>蔡宏遠</item> </string-array></resources>
主要的程序片段，MainActivity:
public class MainActivity extends Activity{ /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // 生成一個SpinnerAdapter SpinnerAdapter adapter = ArrayAdapter.createFromResource(this, R.array.student, android.R.layout.simple_spinner_dropdown_item); // 得到ActionBar ActionBar actionBar = getActionBar(); // 將ActionBar的操作模型設置爲NAVIGATION_MODE_LIST actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_LIST); // 爲ActionBar設置下拉菜單和監聽器 actionBar.setListNavigationCallbacks(adapter, new DropDownListenser()); } /** * 實現 ActionBar.OnNavigationListener接口 */ class DropDownListenser implements OnNavigationListener { // 得到和SpinnerAdapter裏一致的字符數組 String[] listNames = getResources().getStringArray(R.array.student); /* 當選擇下拉菜單項的時候，將Activity中的內容置換爲對應的Fragment */ public boolean onNavigationItemSelected(int itemPosition, long itemId) { // 生成自定的Fragment StudentInfo student = new StudentInfo(); FragmentManager manager = getFragmentManager(); FragmentTransaction transaction = manager.beginTransaction(); // 將Activity中的內容替換成對應選擇的Fragment transaction.replace(R.id.context, student, listNames[itemPosition]); transaction.commit(); return true; } }}