问题
I have developed an application that have one activity and in this activity there are add some fragment in drawer list item (side).So my issue is when I am open on any drawer fragment item and then pressed back button application going to close.So how to handle back event like 3 - 2 -1 when pressed back its open precious fragment.
Code of main activity
public class MainActivity extends FragmentActivity {
private DrawerLayout DrawerLayout;
private ListView DrawerList;
private ActionBarDrawerToggle DrawerToggle;
private CharSequence DrawerTitle;
private CharSequence Title;
private String[] MenuTitles;
private TypedArray MenuIcons;
private DrawerListAdapter adapter;
private ArrayList<DrawerItem> DrawerItems;
@SuppressLint("NewApi")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Title = DrawerTitle = getTitle();
MenuTitles = getResources().getStringArray(R.array.drawer_items);
MenuIcons = getResources().obtainTypedArray(R.array.drawer_icons);
DrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
DrawerList = (ListView) findViewById(R.id.list_slidermenu);
DrawerItems = new ArrayList<DrawerItem>();
DrawerItems.add(new DrawerItem(MenuTitles[0], MenuIcons.getResourceId(
0, -1)));
DrawerItems.add(new DrawerItem(MenuTitles[1], MenuIcons.getResourceId(
1, -1)));
DrawerItems.add(new DrawerItem(MenuTitles[2], MenuIcons.getResourceId(
2, -1)));
DrawerItems.add(new DrawerItem(MenuTitles[3], MenuIcons.getResourceId(
3, -1)));
DrawerItems.add(new DrawerItem(MenuTitles[4], MenuIcons.getResourceId(
4, -1)));
DrawerItems.add(new DrawerItem(MenuTitles[5], MenuIcons.getResourceId(
5, -1)));
DrawerItems.add(new DrawerItem(MenuTitles[6], MenuIcons.getResourceId(
6, -1)));
MenuIcons.recycle();
DrawerList.setOnItemClickListener(new SlideMenuClickListener());
adapter = new DrawerListAdapter(getApplicationContext(), DrawerItems);
DrawerList.setAdapter(adapter);
getActionBar().setDisplayHomeAsUpEnabled(true);
getActionBar().setHomeButtonEnabled(true);
DrawerToggle = new ActionBarDrawerToggle(this, DrawerLayout,
R.drawable.ic_drawer, R.string.app_name, R.string.app_name) {
public void onDrawerClosed(View view) {
getActionBar().setTitle(Title);
invalidateOptionsMenu();
}
public void onDrawerOpened(View drawerView) {
getActionBar().setTitle(DrawerTitle);
invalidateOptionsMenu();
}
};
DrawerLayout.setDrawerListener(DrawerToggle);
if (savedInstanceState == null) {
displayView(0);
}
}
private class SlideMenuClickListener implements
ListView.OnItemClickListener {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
displayView(position);
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (DrawerToggle.onOptionsItemSelected(item)) {
return true;
}
switch (item.getItemId()) {
case R.id.action_settings:
return true;
default:
return super.onOptionsItemSelected(item);
}
}
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
boolean drawerOpen = DrawerLayout.isDrawerOpen(DrawerList);
menu.findItem(R.id.action_settings).setVisible(!drawerOpen);
return super.onPrepareOptionsMenu(menu);
}
@SuppressLint("NewApi")
private void displayView(int position) {
Fragment fragment = null;
switch (position) {
case 0:
fragment = new Home_Activity();
break;
case 1:
fragment = new Activity_two();
break;
case 2:
fragment = new Activity_three();
break;
case 3:
fragment = new Activity_four();
break;
case 4:
fragment = new Activity_five();
break;
case 5:
fragment = new Activity_six();
break;
case 6:
fragment = new Activity_seven();
break;
default:
break;
FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.replace(R.id.frame_container, fragment);
transaction.addToBackStack(null);
transaction.commit();
}
if (fragment != null) {
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction()
.replace(R.id.frame_container, fragment).commit();
DrawerList.setItemChecked(position, true);
DrawerList.setSelection(position);
setTitle(MenuTitles[position]);
DrawerLayout.closeDrawer(DrawerList);
} else {
Log.e("MainActivity", "Error in creating fragment");
}
}
@SuppressLint("NewApi")
@Override
public void setTitle(CharSequence title) {
Title = title;
getActionBar().setTitle(Title);
}
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
DrawerToggle.syncState();
}
one fragment code...
public class Activiy_three extends Fragment {
private GridView gallery;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.activity_three_fragment,
container, false);
List<Item> Images = new ArrayList<Item>();
//todo : develop as per date photo
Images.add(new Item("Image 1", R.drawable.penguins));
Images.add(new Item("Image 1", R.drawable.pulips));
Images.add(new Item("Image 1", R.drawable.lighthouse));
Images.add(new Item("Image 1", R.drawable.koala));
Images.add(new Item("Image 1", R.drawable.jellyfish));
Images.add(new Item("Image 1", R.drawable.hydrangeas));
Images.add(new Item("Image 1", R.drawable.chrysanthemum));
Images.add(new Item("Image 1", R.drawable.home));
gallery = (GridView) v.findViewById(R.id.gridview);
Global.photoAdapter = new PhotoAdapter(getActivity(), Images,false);
gallery.setAdapter(Global.photoAdapter);
gallery.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int
position, long id) {
// Intent i = new Intent(getActivity(), FullImageActivity.class);
// i.putExtra(Global.Id, position);
// startActivity(i);
Fragment fragment = new FullImageActivity();
FragmentManager fragmentManager = getFragmentManager();
Bundle args = new Bundle();
args.putInt(Global.Id, position);
fragment.setArguments(args);
fragmentManager.beginTransaction()
.replace(R.id.frame_container, fragment).commit();
}
});
return v;
}
}
回答1:
You need add the fragment to the backstack
FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.replace(R.id.fragment_container, fragment);
transaction.addToBackStack(null);
transaction.commit();
And you can use popBackStack() to pop the fragment from the stack
http://developer.android.com/reference/android/app/FragmentManager.html#popBackStack()
Edit:
What you have
default:
break;
FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.replace(R.id.frame_container, fragment);
transaction.addToBackStack(null);
transaction.commit();
}
Should be
private void displayView(int position) {
Fragment fragment = null;
switch (position) {
case 0:
fragment = new Home_Activity();
break;
case 1:
fragment = new Activity_two();
break;
case 2:
fragment = new Activity_three();
break;
case 3:
fragment = new Activity_four();
break;
case 4:
fragment = new Activity_five();
break;
case 5:
fragment = new Activity_six();
break;
case 6:
fragment = new Activity_seven();
break;
default:
break;
}
if (fragment != null) {
FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.replace(R.id.frame_container, fragment);
transaction.addToBackStack(null);
transaction.commit();
DrawerList.setItemChecked(position, true);
DrawerList.setSelection(position);
setTitle(MenuTitles[position]);
DrawerLayout.closeDrawer(DrawerList);
} else {
Log.e("MainActivity", "Error in creating fragment");
}
}
回答2:
You can use getName method of FragmentManager.BackStackEntry which is introduced in API level 14 with
FragmentManager.BackStackEntry backEntry=getFragmentManager().getBackStackEntryAt(getActivity().getFragmentManager().getBackStackEntryCount()-1);
String str=backEntry.getName();
Fragment fragment=getFragmentManager().findFragmentByTag(str);
来源：https://stackoverflow.com/questions/22550420/how-to-handle-back-event-in-drawer-list-fragment-in-android-activity