我想在一个FrameLayout加载不同的片段。这个代码在我使用简单的布局文件时运行。但是当我制作一个布局文件时它给出了错误。我的完整代码是
package info.androidhive.slidingmenu;
import info.androidhive.slidingmenu.adapter.NavDrawerListAdapter;
import info.androidhive.slidingmenu.model.NavDrawerItem;
import java.util.ArrayList;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentManager;
import android.content.res.Configuration;
import android.content.res.TypedArray;
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;
public class MainActivity extends Activity {
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);
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
// Home
navDrawerItems.add(new NavDrawerItem(navMenuTitles[0], navMenuIcons.getResourceId(0, -1)));
// Find People
navDrawerItems.add(new NavDrawerItem(navMenuTitles[1], navMenuIcons.getResourceId(1, -1)));
// Photos
navDrawerItems.add(new NavDrawerItem(navMenuTitles[2], navMenuIcons.getResourceId(2, -1)));
// Communities, Will add a counter here
navDrawerItems.add(new NavDrawerItem(navMenuTitles[3], navMenuIcons.getResourceId(3, -1), true, "22"));
// Pages
navDrawerItems.add(new NavDrawerItem(navMenuTitles[4], navMenuIcons.getResourceId(4, -1)));
// What's hot, We will add a counter here
navDrawerItems.add(new NavDrawerItem(navMenuTitles[5], navMenuIcons.getResourceId(5, -1), true, "50+"));
// Recycle the typed array
navMenuIcons.recycle();
mDrawerList.setOnItemClickListener(new SlideMenuClickListener());
// setting the nav drawer list adapter
adapter = new NavDrawerListAdapter(getApplicationContext(),
navDrawerItems);
mDrawerList.setAdapter(adapter);
// enabling action bar app icon and behaving it as toggle button
getActionBar().setDisplayHomeAsUpEnabled(true);
getActionBar().setHomeButtonEnabled(true);
mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
R.drawable.ic_drawer, //nav menu toggle icon
R.string.app_name, // nav drawer open - description for accessibility
R.string.app_name // nav drawer close - description for accessibility
) {
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);
}
}
/**
* 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);
}
}
@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);
}
/**
* Diplaying 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 HomeFragment();
break;
case 1:
fragment = new FindPeopleFragment();
break;
case 2:
fragment = new PhotosFragment();
break;
case 3:
fragment = new CommunityFragment();
break;
case 4:
fragment = new PagesFragment();
break;
case 5:
fragment = new WhatsHotFragment();
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 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 change to the drawer toggls
mDrawerToggle.onConfigurationChanged(newConfig);
}
}
片段类是，
package info.androidhive.slidingmenu;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class HomeFragment extends Fragment {
public HomeFragment(){}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.frag_home, container, false);
return rootView;
}
}
布局文件frag_home是，
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/lin_lay_home"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:weightSum="100" >
<fragment
android:id="@+id/frg_home"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="80" />
<LinearLayout
android:id="@+id/linlay_home_button"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="20"
android:orientation="horizontal"
android:weightSum="100" >
<Button
android:id="@+id/btn_lin_vote"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="20"
android:text="Vote" />
<Button
android:id="@+id/btn_lin_vote"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="20"
android:text="Vote" />
<Button
android:id="@+id/btn_lin_vote"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="20"
android:text="Vote" />
<Button
android:id="@+id/btn_lin_vote"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="20"
android:text="Vote" />
<Button
android:id="@+id/btn_lin_vote"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="20"
android:text="Vote" />
</LinearLayout>
</LinearLayout>
运行应用程序后，它出现以下错误
01-31 07:33:40.617: E/AndroidRuntime(3751): java.lang.RuntimeException: Unable to start activity ComponentInfo{info.androidhive.slidingmenu/info.androidhive.slidingmenu.MainActivity}: android.view.InflateException: Binary XML file line #8: Error inflating class fragment
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.app.ActivityThread.access$600(ActivityThread.java:141)
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.os.Handler.dispatchMessage(Handler.java:99)
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.os.Looper.loop(Looper.java:137)
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.app.ActivityThread.main(ActivityThread.java:5041)
01-31 07:33:40.617: E/AndroidRuntime(3751): at java.lang.reflect.Method.invokeNative(Native Method)
01-31 07:33:40.617: E/AndroidRuntime(3751): at java.lang.reflect.Method.invoke(Method.java:511)
01-31 07:33:40.617: E/AndroidRuntime(3751): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
01-31 07:33:40.617: E/AndroidRuntime(3751): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
01-31 07:33:40.617: E/AndroidRuntime(3751): at dalvik.system.NativeStart.main(Native Method)
01-31 07:33:40.617: E/AndroidRuntime(3751): Caused by: android.view.InflateException: Binary XML file line #8: Error inflating class fragment
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
01-31 07:33:40.617: E/AndroidRuntime(3751): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:270)
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.app.Activity.setContentView(Activity.java:1881)
01-31 07:33:40.617: E/AndroidRuntime(3751): at info.androidhive.slidingmenu.MainActivity.onCreate(MainActivity.java:45)
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.app.Activity.performCreate(Activity.java:5104)
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
01-31 07:33:40.617: E/AndroidRuntime(3751): ... 11 more
01-31 07:33:40.617: E/AndroidRuntime(3751): Caused by: java.lang.NullPointerException: name == null
01-31 07:33:40.617: E/AndroidRuntime(3751): at java.lang.VMClassLoader.findLoadedClass(Native Method)
01-31 07:33:40.617: E/AndroidRuntime(3751): at java.lang.ClassLoader.findLoadedClass(ClassLoader.java:354)
01-31 07:33:40.617: E/AndroidRuntime(3751): at java.lang.ClassLoader.loadClass(ClassLoader.java:491)
01-31 07:33:40.617: E/AndroidRuntime(3751): at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.app.Fragment.instantiate(Fragment.java:582)
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.app.Fragment.instantiate(Fragment.java:560)
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.app.Activity.onCreateView(Activity.java:4709)
01-31 07:33:40.617: E/AndroidRuntime(3751): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:680)
01-31 07:33:40.617: E/AndroidRuntime(3751): ... 21 more
答案 0 :(得分：0)
HomeFragment正在给一个布局充气，而布局又有另一个片段。 4.2之前的版本不支持嵌套片段。要了解嵌套片段，请检查the official page。并且，正如所述there，
当布局包含时，您无法将布局扩展为片段 a＆lt;片段＆gt;。只有在添加到a时才支持嵌套片段 动态分段。
查看this答案以获取更多信息。
答案 1 :(得分：0)
目前不支持嵌套片段。试图将片段放在另一个片段的UI中会导致未定义且可能破坏的行为。
更新：自Android 4.2（以及Android支持图书馆第11版）起支持嵌套片段：http://developer.android.com/about/versions/android-4.2.html#NestedFragments
注意（根据this docs）：“注意：当布局包含<fragment>时，您无法将布局扩展为片段。嵌套片段仅限于在动态添加到片段时受支持。“