我正在使用NavigationDrawer作为主要活动，但是当我转到另一个片段时，我想修改菜单，将箭头放回到主页并隐藏导航栏的搜索图标，所以我有两个问题在这里，我可以在更改片段时隐藏搜索图标，但是当我回到导航主页时它应该再次可见，这不会发生，如果我在另一个片段中，则必须删除导航栏并且必须出现箭头才能回到家里，这是我到目前为止所尝试的：
public class NavigationMain extends ActionBarActivity{
private DrawerLayout mDrawerLayout;
private ListView mDrawerList;
private android.support.v7.app.ActionBarDrawerToggle mDrawerToggle;
private CharSequence mDrawerTitle;
private CharSequence mTitle;
private String[] mPlanetTitles;
static Toolbar toolbar;
TextView toolbartitle;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.navigation_main);
mPlanetTitles = getResources().getStringArray(R.array.planets_array);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
mDrawerList = (ListView) findViewById(R.id.left_drawer);
toolbar = (Toolbar) findViewById(R.id.my_awesome_toolbar);
toolbartitle = (TextView) findViewById(R.id.titletool);
mDrawerList.setAdapter(new ArrayAdapter<String>(this,
R.layout.drawer_list_item, mPlanetTitles));
mDrawerList.setOnItemClickListener(new DrawerItemClickListener());
mDrawerToggle = new android.support.v7.app.ActionBarDrawerToggle(
this, /* host Activity */
mDrawerLayout, /* DrawerLayout object */
toolbar, /* nav drawer image to replace 'Up' caret */
R.string.drawer_open, /* "open drawer" description for accessibility */
R.string.drawer_close /* "close drawer" description for accessibility */
) {
public void onDrawerClosed(View view) {
//getSupportActionBar().setTitle(mTitle);
toolbartitle.setText(mTitle);
getSupportActionBar().setDisplayShowTitleEnabled(false);
invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
}
public void onDrawerOpened(View drawerView) {
//getSupportActionBar().setTitle(mDrawerTitle);
toolbartitle.setText(mDrawerTitle);
getSupportActionBar().setDisplayShowTitleEnabled(false);
invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
}
};
setSupportActionBar(toolbar);
mDrawerLayout.setDrawerListener(mDrawerToggle);
getSupportActionBar().setDisplayShowTitleEnabled(false);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
toolbartitle.setText("Nav");
toolbar.inflateMenu(R.menu.main);
mDrawerToggle.syncState();
if (savedInstanceState == null) {
selectItem(0);
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
return super.onCreateOptionsMenu(menu);
}
/* Called whenever we call invalidateOptionsMenu() */
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
// If the nav drawer is open, hide action items related to the content view
return super.onPrepareOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// The action bar home/up action should open or close the drawer.
// ActionBarDrawerToggle will take care of this.
if (mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
// Handle action buttons
switch (item.getItemId()) {
case R.id.action_websearch:
// create intent to perform web search for this planet
Intent intent = new Intent(Intent.ACTION_WEB_SEARCH);
intent.putExtra(SearchManager.QUERY, toolbartitle.getText());
// catch event that there's no activity to handle intent
if (intent.resolveActivity(getPackageManager()) != null) {
startActivity(intent);
} else {
Toast.makeText(this, R.string.app_not_available, Toast.LENGTH_LONG).show();
}
return true;
default:
return super.onOptionsItemSelected(item);
}
}
/* The click listner for ListView in the navigation drawer */
private class DrawerItemClickListener implements ListView.OnItemClickListener {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
selectItem(position);
}
}
private void selectItem(int position) {
FragmentManager fragmentManager = getSupportFragmentManager();
Fragment fragment = new InstituicoesFragment();
switch (position) {
case 0:
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();
break;
}
// Load your conten here
Toast.makeText(NavigationMain.this, "Position" + position, Toast.LENGTH_LONG).show();
// update selected item and title, then close the drawer
mDrawerList.setItemChecked(position, true);
mDrawerLayout.closeDrawer(mDrawerList);
}
@Override
public void setTitle(CharSequence title) {
mTitle = title;
//getSupportActionBar().setTitle(mTitle);
toolbartitle.setText(mTitle);
}
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
// Sync the toggle state after onRestoreInstanceState has occurred.
mDrawerToggle.syncState();
}
@Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
// Pass any configuration change to the drawer toggls
mDrawerToggle.onConfigurationChanged(newConfig);
}
@Override
public void onBackPressed() {
super.onBackPressed();
}
}
在我的片段中，我添加以下内容：
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.main, menu);
menu.removeItem(R.id.action_websearch);
super.onCreateOptionsMenu(menu, inflater);
}
答案 0 :(得分：1)
我使用这种方法： 我给动作栏的菜单充气，其中包含所有项目。 然后在Activity onCreateOptionsMenu（）中检查显示的片段，并相应地设置项目的可见性。 然后在onSectionAttached方法中我调用invalidateOptionsMenu（）;这将重新加载onCreateOptionsMenu所以我可以在选择的每个片段上有不同的菜单项
用于检查我是否使用布尔标志，如果该标志为真，则表示该片段是n视图，如：
查看第一个片段：
ft.replace(R.id.container, firstFragment);
firstfragmentIsOn=true;
secondFragmentIsOn=false;
查看第二个片段：
ft.replace(R.id.container, secondFragment);
firstfragmentIsOn=false;
secondFragmentIsOn=true;
并在onCreateOptionsMenu中：
MenuItem item1=menu.findItem(R.id.item1);
MenuItem item2=menu.findItem)(R.id.item2);
if(firstfragmentIsOn)
{
item1.setVisible(true);
item2.setVisible(false);
}
if(secondFragmentIsOn)
{
item1.setVisible(false);
item2.setVisible(true);
}