我有一个应用程序，其主活动有一个带菜单抽屉的操作栏。选择抽屉中的项目时，将更新主活动中的片段。有一个片段在选择行时显示新活动。我正在尝试使用操作栏从该新活动向上导航。我有它的工作，但它加载主要活动与它的默认片段而不是以前显示的片段。我应该使用onSaveInstanceState吗？
这是我的新活动。
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch(item.getItemId()) {
case android.R.id.home:
NavUtils.navigateUpFromSameTask(this);
return true;
default:
return super.onOptionsItemSelected(item);
}
}
在我的清单中：
<activity android:name=".AutoBenefits"
android:label="@string/app_name"
android:screenOrientation="portrait"
android:theme="@android:style/Theme.Holo.Light.DarkActionBar">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value=".MainActivity" />
</activity>
MainActivity
package kyfb.android.kyfb.com.kyfb;
import android.app.ActionBar;
import android.app.Activity;
import android.app.FragmentManager;
import android.content.Intent;
import android.content.res.Configuration;
import android.content.res.TypedArray;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.os.Bundle;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.widget.DrawerLayout;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.app.Fragment;
import java.util.ArrayList;
public class MainActivity extends BaseActivity {
private DrawerLayout mDrawerLayout;
private ListView mDrawerList;
private ActionBarDrawerToggle mDrawerToggle;
// nav drawer title
private CharSequence mDrawerTitle;
// used to store app title
private CharSequence mTitle;
// slide menu items
private String[] navMenuTitles;
private TypedArray navMenuIcons;
private ArrayList<NavDrawerItem> navDrawerItems;
private NavDrawerListAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ActionBar bar = getActionBar();
bar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#0E4D8B")));
mTitle = mDrawerTitle = getTitle();
// load slide menu items
navMenuTitles = getResources().getStringArray(R.array.nav_drawer_items);
// nav drawer icons from resources
navMenuIcons = getResources().obtainTypedArray(R.array.nav_drawer_icons);
mDrawerLayout = (DrawerLayout)findViewById(R.id.drawer_layout);
mDrawerList = (ListView)findViewById(R.id.list_slidermenu);
navDrawerItems = new ArrayList<NavDrawerItem>();
// adding nav drawer items to array
navDrawerItems.add(new NavDrawerItem(navMenuTitles[0], navMenuIcons.getResourceId(0, -1)));
navDrawerItems.add(new NavDrawerItem(navMenuTitles[1], navMenuIcons.getResourceId(1, -1)));
navDrawerItems.add(new NavDrawerItem(navMenuTitles[2], navMenuIcons.getResourceId(2, -1)));
navDrawerItems.add(new NavDrawerItem(navMenuTitles[3], navMenuIcons.getResourceId(3, -1)));
navDrawerItems.add(new NavDrawerItem(navMenuTitles[4], navMenuIcons.getResourceId(4, -1)));
navDrawerItems.add(new NavDrawerItem(navMenuTitles[5], navMenuIcons.getResourceId(5, -1)));
navDrawerItems.add(new NavDrawerItem(navMenuTitles[6], navMenuIcons.getResourceId(6, -1)));
navDrawerItems.add(new NavDrawerItem(navMenuTitles[7], navMenuIcons.getResourceId(7, -1)));
navDrawerItems.add(new NavDrawerItem(navMenuTitles[8], navMenuIcons.getResourceId(8, -1)));
navDrawerItems.add(new NavDrawerItem(navMenuTitles[9], navMenuIcons.getResourceId(9, -1)));
navDrawerItems.add(new NavDrawerItem(navMenuTitles[10], navMenuIcons.getResourceId(10, -1)));
navDrawerItems.add(new NavDrawerItem(navMenuTitles[11], navMenuIcons.getResourceId(11, -1)));
navDrawerItems.add(new NavDrawerItem(navMenuTitles[12], navMenuIcons.getResourceId(12, -1)));
navDrawerItems.add(new NavDrawerItem(navMenuTitles[13], navMenuIcons.getResourceId(13, -1)));
navDrawerItems.add(new NavDrawerItem(navMenuTitles[14], navMenuIcons.getResourceId(14, -1)));
// recycle the typed array
navMenuIcons.recycle();
// setting the nav drawer list adapter
adapter = new NavDrawerListAdapter(getApplicationContext(), navDrawerItems);
mDrawerList.setAdapter(adapter);
// enabling action bar app icon and set it as toggle button
getActionBar().setDisplayHomeAsUpEnabled(true);
getActionBar().setHomeButtonEnabled(true);
mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout, R.drawable.ic_drawer,
R.string.app_name, R.string.app_name) {
public void onDrawerClosed(View view) {
getActionBar().setTitle(mTitle);
// calling onPrepareOptionsMenu() to show action bar icons
invalidateOptionsMenu();
}
public void onDrawerOpened(View drawerView) {
getActionBar().setTitle(mDrawerTitle);
// calling onPrepareOptionsMenu() to hide action bar icons
invalidateOptionsMenu();
}
};
mDrawerLayout.setDrawerListener(mDrawerToggle);
if(savedInstanceState == null) {
// on first time display view for first nav item
displayView(0);
}
mDrawerList.setOnItemClickListener(new SlideMenuClickListener());
}
/**
* Slide menu item click listener
*/
private class SlideMenuClickListener implements ListView.OnItemClickListener {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// display view for selected nav drawer item
displayView(position);
}
}
/**
* Displaying fragment view for selected nav drawer list item
*/
private void displayView(int position) {
// update the main content by replacing fragments
Fragment fragment = null;
switch (position) {
case 0:
fragment = new ActionAlertsFragment();
break;
case 1:
fragment = new AgNewsFragment();
break;
case 2:
fragment = new MarketUpdatesFragment();
break;
case 3:
fragment = new ToursFragment();
break;
case 4:
fragment = new KFBMagFragment();
break;
case 5:
fragment = new BenefitsFragment();
break;
default:
break;
}
if(fragment != null) {
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.frame_container, fragment).commit();
// update selected item and title, then close the drawer
mDrawerList.setItemChecked(position, true);
mDrawerList.setSelection(position);
setTitle(navMenuTitles[position]);
mDrawerLayout.closeDrawer(mDrawerList);
}
else {
// error in creating fragment
Log.e("MainActivity", "Error in creating fragment");
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// toggle nav drawer on selecting action bar app icon/title
if(mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
// handle action bar actions click
switch(item.getItemId()) {
case R.id.action_settings:
return true;
default:
return super.onOptionsItemSelected(item);
}
}
/***
* Called when invalidateOptionsMenu() is triggered
*/
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
// if nav drawer is opened, hide the action items
boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
menu.findItem(R.id.action_settings).setVisible(!drawerOpen);
return super.onPrepareOptionsMenu(menu);
}
@Override
public void setTitle(CharSequence title) {
mTitle = title;
getActionBar().setTitle(mTitle);
}
/**
* When using the ActionBarDrawerToggle, you must call it during
* onPostCreate() and onConfigurationChanged()...
*/
@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 changes to the drawer toggle
mDrawerToggle.onConfigurationChanged(newConfig);
}
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
}
@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
}
}
答案 0 :(得分：0)
如果你的片段都在后面的堆栈上，只需调用弹出片段管理器中的后端堆栈而不是向上导航。
示例：
case android.R.id.home:
NavUtils.navigateUpFromSameTask(this);
return true;
更改为：
case android.R.id.home:
getFragmentManager().popBackStackImmediate();
return true;
此外：
fragmentManager.beginTransaction().replace(R.id.frame_container, fragment).commit();
到
fragmentManager.beginTransaction().replace(R.id.frame_container, fragment).addToBackstack(null).commit();