I have an application with three tabs.
Each tab has its own layout .xml file. The main.xml has its own map fragment. It’s the one that shows up when the application first launches.
Everything works fine except for when I change between tabs. If I try to switch back to the map fragment tab, I get this error. Switching to and between other tabs works just fine.
What could be wrong here?
This is my main class and my main.xml, as well as a relevant class that I use ( you will also find the error log at the bottom )
main class
package com.nfc.demo;
import android.app.ActionBar;
import android.app.ActionBar.Tab;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.widget.Toast;
public class NFCDemoActivity extends Activity {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ActionBar bar = getActionBar();
bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
bar.setDisplayOptions(0, ActionBar.DISPLAY_SHOW_TITLE);
bar.addTab(bar
.newTab()
.setText("Map")
.setTabListener(
new TabListener<MapFragment>(this, "map",
MapFragment.class)));
bar.addTab(bar
.newTab()
.setText("Settings")
.setTabListener(
new TabListener<SettingsFragment>(this, "settings",
SettingsFragment.class)));
bar.addTab(bar
.newTab()
.setText("About")
.setTabListener(
new TabListener<AboutFragment>(this, "about",
AboutFragment.class)));
if (savedInstanceState != null) {
bar.setSelectedNavigationItem(savedInstanceState.getInt("tab", 0));
}
// setContentView(R.layout.main);
}
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt("tab", getActionBar().getSelectedNavigationIndex());
}
public static class TabListener<T extends Fragment> implements
ActionBar.TabListener {
private final Activity mActivity;
private final String mTag;
private final Class<T> mClass;
private final Bundle mArgs;
private Fragment mFragment;
public TabListener(Activity activity, String tag, Class<T> clz) {
this(activity, tag, clz, null);
}
public TabListener(Activity activity, String tag, Class<T> clz,
Bundle args) {
mActivity = activity;
mTag = tag;
mClass = clz;
mArgs = args;
// Check to see if we already have a fragment for this tab,
// probably from a previously saved state. If so, deactivate
// it, because our initial state is that a tab isn't shown.
mFragment = mActivity.getFragmentManager().findFragmentByTag(mTag);
if (mFragment != null && !mFragment.isDetached()) {
FragmentTransaction ft = mActivity.getFragmentManager()
.beginTransaction();
ft.detach(mFragment);
ft.commit();
}
}
public void onTabSelected(Tab tab, FragmentTransaction ft) {
if (mFragment == null) {
mFragment = Fragment.instantiate(mActivity, mClass.getName(),
mArgs);
ft.add(android.R.id.content, mFragment, mTag);
} else {
ft.attach(mFragment);
}
}
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
if (mFragment != null) {
ft.detach(mFragment);
}
}
public void onTabReselected(Tab tab, FragmentTransaction ft) {
Toast.makeText(mActivity, "Reselected!", Toast.LENGTH_SHORT)
.show();
}
}
}
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<fragment
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/mapFragment"
android:name="com.google.android.gms.maps.MapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
relevant class ( MapFragment.java )
package com.nfc.demo;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class MapFragment extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
return inflater.inflate(R.layout.main, container, false);
}
public void onDestroy() {
super.onDestroy();
}
}
error
android.view.InflateException: Binary XML file line #7:
Error inflating class fragment
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
at com.nfc.demo.MapFragment.onCreateView(MapFragment.java:15)
at android.app.Fragment.performCreateView(Fragment.java:1695)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:885)
at android.app.FragmentManagerImpl.attachFragment(FragmentManager.java:1255)
at android.app.BackStackRecord.run(BackStackRecord.java:672)
at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1435)
at android.app.FragmentManagerImpl$1.run(FragmentManager.java:441)
at android.os.Handler.handleCallback(Handler.java:725)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5039)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.IllegalArgumentException:
Binary XML file line #7: Duplicate id 0x7f040005, tag null, or
parent id 0xffffffff with another fragment for
com.google.android.gms.maps.MapFragment
at android.app.Activity.onCreateView(Activity.java:4722)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:680)
... 19 more
The answer Matt suggests works, but it causes the map to be recreated and redrawn, which isn’t always desirable.
After lots of trial and error, I found a solution that works for me:
For good measure, here’s "map.xml" (R.layout.map) with R.id.mapFragment (android:id="@+id/mapFragment"):
I hope this helps, but I can’t guarantee that it doesn’t have any adverse effects.
Edit: There were some adverse effects, such as when exiting the application and starting it again. Since the application isn’t necessarily completely shut down (but just put to sleep in the background), the previous code i submitted would fail upon restarting the application. I’ve updated the code to something that works for me, both going in & out of the map and exiting and restarting the application, I’m not too happy with the try-catch bit, but it seem to work well enough.
When looking at the stack trace it occurred to me that I could just check if the map fragment is in the FragmentManager, no need for the try-catch block, code updated.More edits: It turns out that you need that try-catch after all. Just checking for the map fragment turned out not to work so well after all. Blergh.