Android 菜单动态变化添加或去除

天下之事常成于困约，而败于奢靡。这篇文章主要讲述Android 菜单动态变化添加或去除相关的知识，希望能为你提供帮助。

< menu xmlns:android="http://schemas.android.com/apk/res/android"> < group android:id="@+id/menu_items"> < item android:id="@+id/menu_item_night_mode" android:title="@string/menu_item_night_mode" android:icon="@android:drawable/ic_menu_preferences"/> < item android:id="@+id/menu_item_settings" android:title="@string/menu_item_settings" android:icon="@android:drawable/ic_menu_preferences"/> < item android:id="@+id/menu_item_help" android:title="@string/menu_item_help" android:icon="@android:drawable/ic_menu_preferences"/> < /group> < /menu>

@Override public boolean onCreateOptionsMenu(Menu menu) { // We only want to show it as a menu in landscape, and only for clock/alarm fragment. mMenu = menu; //方向水平 if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) { if (mActionBar.getSelectedNavigationIndex() == ALARM_TAB_INDEX || mActionBar.getSelectedNavigationIndex() == CLOCK_TAB_INDEX) { // Clear the menu so that it doesn‘t get duplicate items in case onCreateOptionsMenu // was called multiple times. menu.clear(); getMenuInflater().inflate(R.menu.desk_clock_menu, menu); MenuItem nightMode = menu.findItem(R.id.menu_item_night_mode); MenuItem help = menu.findItem(R.id.menu_item_help); if (mActionBar.getSelectedNavigationIndex() == ALARM_TAB_INDEX) { nightMode.setVisible(false); help.setVisible(false); } else if (mActionBar.getSelectedNavigationIndex() == CLOCK_TAB_INDEX) { nightMode.setVisible(true); help.setVisible(false); }} // Always return true for landscape, regardless of whether we‘ve inflated the menu, so // that when we switch tabs this method will get called and we can inflate the menu. return true; } return false; }@Override public boolean onPrepareOptionsMenu(Menu menu) { updateMenu(menu); return true; }private void updateMenu(Menu menu) { // Hide "help" if we don‘t have a URI for it. MenuItem help = menu.findItem(R.id.menu_item_help); if (help != null) { Utils.prepareHelpMenuItem(this, help); }// Hide "lights out" for timer. MenuItem nightMode = menu.findItem(R.id.menu_item_night_mode); if (mActionBar.getSelectedNavigationIndex() == ALARM_TAB_INDEX) { nightMode.setVisible(false); } else if (mActionBar.getSelectedNavigationIndex() == CLOCK_TAB_INDEX) { nightMode.setVisible(true); } }@Override public boolean onOptionsItemSelected(MenuItem item) { if (processMenuClick(item)) { return true; }return super.onOptionsItemSelected(item); }private boolean processMenuClick(MenuItem item) { switch (item.getItemId()) { case R.id.menu_item_settings: startActivity(new Intent(DeskClock.this, SettingsActivity.class)); return true; case R.id.menu_item_help: Intent i = item.getIntent(); if (i != null) { try { startActivity(i); } catch (ActivityNotFoundException e) { // No activity found to match the intent - ignore } } return true; case R.id.menu_item_night_mode: startActivity(new Intent(DeskClock.this, ScreensaverActivity.class)); default: break; } return true; }

【Android 菜单动态变化添加或去除】