在我的应用程序中，我使用了SherlockNavigationDrawer。默认情况下，navigationDrawer有3个菜单可以打开3个片段。我修改了以下片段之一。但是当我的片段菜单第二次点击时，屏幕不会显示任何内容！第一次，没问题;但第二次显示空白页面。
在这种情况下，如果单击NavigationDrawer中的默认片段菜单，然后单击屏幕上的片段，则返回，但如果再次单击我的片段菜单，则屏幕显示空白页面！
此外，我在我的片段中显示了一个项目列表，通过单击每个项目替换显示特定项目详细信息的新片段。但细节片段是一个空的显示!!!
友！问题在哪里？
MainActivity Code：
public class ActivityMain extends SherlockFragmentActivity {
// Declare Variables
DrawerLayout mDrawerLayout;
ListView mDrawerList;
ActionBarDrawerToggle mDrawerToggle;
MenuListAdapter mMenuAdapter;
String[] title;
String[] subtitle;
int[] icon;
Fragment fragment1 = new Fragment1();
Fragment fragment2 = new Fragment2();
Fragment fragment_categorylist = new Fragment_CategoryList();
private CharSequence mDrawerTitle;
private CharSequence mTitle;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Get the view from drawer_main.xml
setContentView(R.layout.drawer_main);
// Get the Title
mTitle = mDrawerTitle = getTitle();
// Generate title
title = new String[] { getString(R.string.TitleFragment1),
getString(R.string.TitleFragment2),
getString(R.string.TitleFragment3) };
// Generate subtitle
subtitle = new String[] { getString(R.string.SubtitleFragment1),
getString(R.string.SubtitleFragment2),
getString(R.string.SubtitleFragment3) };
// Generate icon
icon = new int[] { R.drawable.action_about, R.drawable.action_settings,
R.drawable.collections_cloud };
// Locate DrawerLayout in drawer_main.xml
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
// Locate ListView in drawer_main.xml
mDrawerList = (ListView) findViewById(R.id.listview_drawer);
// Set a custom shadow that overlays the main content when the drawer
// opens
mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow,
GravityCompat.START);
mDrawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_UNLOCKED);
ActivitySwipeDetector swipe = new ActivitySwipeDetector(this);
DrawerLayout swipe_layout = (DrawerLayout) findViewById(R.id.drawer_layout);
swipe_layout.setOnTouchListener(swipe);
//LinearLayout swipe_layout2 = (LinearLayout) findViewById(R.id.fragment_pager_layout);
//swipe_layout2.setOnTouchListener(swipe);
// Pass string arrays to MenuListAdapter
mMenuAdapter = new MenuListAdapter(ActivityMain.this, title, subtitle,
icon);
// Set the MenuListAdapter to the ListView
mDrawerList.setAdapter(mMenuAdapter);
// Capture listview menu item click
mDrawerList.setOnItemClickListener(new DrawerItemClickListener());
// Enable ActionBar app icon to behave as action to toggle nav drawer
getSupportActionBar().setHomeButtonEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
// ActionBarDrawerToggle ties together the the proper interactions
// between the sliding drawer and the action bar app icon
mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
R.drawable.ic_drawer, R.string.drawer_open,
R.string.drawer_close) {
public void onDrawerClosed(View view) {
// TODO Auto-generated method stub
super.onDrawerClosed(view);
}
public void onDrawerOpened(View drawerView) {
// TODO Auto-generated method stub
// Set the title on the action when drawer open
getSupportActionBar().setTitle(mDrawerTitle);
super.onDrawerOpened(drawerView);
}
};
mDrawerLayout.setDrawerListener(mDrawerToggle);
if (savedInstanceState == null) {
selectItem(0);
}
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == android.R.id.home) {
if (mDrawerLayout.isDrawerOpen(mDrawerList)) {
mDrawerLayout.closeDrawer(mDrawerList);
} else {
mDrawerLayout.openDrawer(mDrawerList);
}
}
return super.onOptionsItemSelected(item);
}
// ListView click listener 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) {
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
// Locate Position
switch (position) {
case 0:
ft.replace(R.id.content_frame, fragment1);
break;
case 1:
ft.replace(R.id.content_frame, fragment2);
break;
case 2:
ft.replace(R.id.content_frame, fragment_categorylist);
break;
}
ft.commit();
mDrawerList.setItemChecked(position, true);
// Get the title followed by the position
setTitle(title[position]);
// Close drawer
mDrawerLayout.closeDrawer(mDrawerList);
}
默认片段代码：
public class Fragment3 extends SherlockFragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment3, container, false);
return rootView;
}
}
My Fragment（Modified Fragment）：
public class Fragment_CategoryList extends SherlockFragment {
static final int NUM_ITEMS = 1;
MyAdapter mAdapter;
ViewPager mPager;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_pager, container,
false);
mAdapter = new MyAdapter(getSherlockActivity().getSupportFragmentManager());
mPager = (ViewPager) rootView.findViewById(R.id.pager);
mPager.setAdapter(mAdapter);
// Watch for button clicks.
Button button = (Button) rootView.findViewById(R.id.goto_first);
button.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
mPager.setCurrentItem(0);
}
});
button = (Button) rootView.findViewById(R.id.goto_last);
button.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
mPager.setCurrentItem(NUM_ITEMS - 1);
}
});
return rootView;
}
// ////////////////////////////////////////////////////////////////////////
public static class MyAdapter extends FragmentPagerAdapter {
public MyAdapter(FragmentManager fm) {
super(fm);
}
@Override
public int getCount() {
return NUM_ITEMS;
}
@Override
public Fragment getItem(int position) {
return ArrayListFragment.newInstance(position);
}
}
public static class ArrayListFragment extends SherlockListFragment {
int mNum;
/**
* Create a new instance of CountingFragment, providing "num" as an
* argument.
*/
static ArrayListFragment newInstance(int num) {
ArrayListFragment f = new ArrayListFragment();
// Supply num input as an argument.
Bundle args = new Bundle();
args.putInt("num", num);
f.setArguments(args);
return f;
}
/**
* When creating, retrieve this instance's number from its arguments.
*/
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mNum = getArguments() != null ? getArguments().getInt("num") : 1;
}
/**
* The Fragment's UI is just a simple text view showing its instance
* number.
*/
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_pager_list, container,
false);
View tv = v.findViewById(R.id.text);
((TextView) tv).setText("Fragment #" + mNum);
return v;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
// setListAdapter(new ArrayAdapter<String>(getActivity(),
// android.R.layout.simple_list_item_1, Cheeses.sCheeseStrings));
DBAdapter db = new DBAdapter(getActivity());
// Create an array to specify the fields we want to display in the
// list (only TITLE)
String[] from = new String[] { "title", "_id" };
// and an array of the fields we want to bind those fields to (in
// this case just text1)
int[] to = new int[] { R.id.entry1, R.id.entry2 };
ArrayList<HashMap<String, String>> categoryList = db.getAll();
if (categoryList.size() != 0) {
ListAdapter adapter = new SimpleAdapter(getActivity(),
categoryList,
R.layout.fragment_pager_list_entry, from, to);
setListAdapter(adapter);
}
}
@Override
public void onListItemClick(ListView l, View v, int position, long id) {
final FragmentTransaction ft = getSherlockActivity().getSupportFragmentManager().beginTransaction();
Fragment myFragment = new Fragment_QA();
int idplus = (int)id + 1;
Bundle args = new Bundle();
args.putLong("cid", idplus);
//myFragment.setArguments(args);
ft.replace(((ViewGroup)(getView().getParent())).getId(), myFragment);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
ft.addToBackStack(null);
ft.commit();
}
}
}
主要活动用户界面：
<android.support.v4.widget.DrawerLayout
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<FrameLayout
android:id="@+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<ListView
android:id="@+id/listview_drawer"
android:layout_width="240dp"
android:layout_height="match_parent"
android:layout_gravity="start"
android:background="#111"
android:choiceMode="singleChoice"
android:divider="@android:color/transparent"
android:dividerHeight="0dp" />
My Fragment UI（Fragment_CategoryList）：
<LinearLayout
android:orientation="vertical" android:padding="4dip"
android:gravity="center_horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<android.support.v4.view.ViewPager
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="0px"
android:layout_weight="1">
</android.support.v4.view.ViewPager>
<LinearLayout android:orientation="horizontal"
android:gravity="center" android:measureWithLargestChild="true"
android:layout_width="match_parent" android:layout_height="wrap_content"
android:layout_weight="0">
<Button android:id="@+id/goto_first"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:text="FIRST">
</Button>
<Button android:id="@+id/goto_last"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:text="LAST">
</Button>
</LinearLayout>
答案 0 :(得分：0)
我不知道这个问题是否仍然存在，但是对于某人来说可能是一个有用的答案。
这就是您应该做的：
从
android.support.v4.app.FragmentPagerAdapter至android.support.v4.app.FragmentStatePagerAdapter