我认为我与this problem有类似的问题，但是我的标签使用了不同的布局。
我使用Google的SlidingTabLayout / Strip来制作可跳转的标签布局。每个选项卡都是一个包含TextView的Fragment，每个TextView都通过AsyncRetriever进程更新。
目前，它是这样的：
+------------------------+
+ TAB 1 | TAB 2 | TAB 3 +
+------------------------+
+ +
+ +
最初，每个标签加载正常。选项卡1最初填充，然后当我滑动到选项卡2和3时，它们也加载正常。有趣的问题是当我尝试将新数据注入数据库，然后在我的应用程序上观察数据刷新时。
例如，我更新了数据库中Tab 1的内容。如果我当前在标签1上并选择标签3，则返回标签1，我会看到所反映的更改。
但是，如果我选择Tab 2，那么返回选项卡1，我从未看到更改（直到我点击Tab 3）。相反的问题也是如此。此外，如果我转到Tab 1或3然后回到2，我永远不会在Tab 2中进行任何更新更新。基本上，我认为每当我刷卡时我的视图刷新都会有问题，而且不知何故Tab 2是死区。
这是我的MainActivity课程：
public class MainActivity extends ActionBarActivity {
Toolbar toolbar;
ViewPager pager;
ViewPagerAdapter adapter;
SlidingTabLayout tabs;
CharSequence titles[]={"MAIN","INVENTORY","ATTRIBUTES"};
int num_tabs = titles.length;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Creating The Toolbar and setting it as the Toolbar for the activity
toolbar = (Toolbar) findViewById(R.id.tool_bar);
setSupportActionBar(toolbar);
// Creating The ViewPagerAdapter and Passing Fragment Manager, Titles fot the Tabs and Number Of Tabs.
adapter = new ViewPagerAdapter(getSupportFragmentManager(),titles,num_tabs,MainActivity.this);
// Assigning ViewPager View and setting the adapter
pager = (ViewPager) findViewById(R.id.pager);
pager.setAdapter(adapter);
// Assiging the Sliding Tab Layout View
tabs = (SlidingTabLayout) findViewById(R.id.tabs);
tabs.setDistributeEvenly(true); // To make the Tabs Fixed set this true, This makes the tabs Space Evenly in Available width
// Setting Custom Color for the Scroll bar indicator of the Tab View
tabs.setCustomTabColorizer(new SlidingTabLayout.TabColorizer() {
@Override
public int getIndicatorColor(int position) {
return getResources().getColor(R.color.tabsScrollColor);
}
});
// Setting the ViewPager For the SlidingTabsLayout
tabs.setViewPager(pager);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
和我的ViewPagerAdapter：
public class ViewPagerAdapter extends FragmentStatePagerAdapter {
CharSequence Titles[]; // This will Store the Titles of the Tabs which are Going to be passed when ViewPagerAdapter is created
int NumbOfTabs; // Store the number of tabs, this will also be passed when the ViewPagerAdapter is created
Activity mainActivity; // track the activity
// Build a Constructor and assign the passed Values to appropriate values in the class
public ViewPagerAdapter(FragmentManager fm,CharSequence mTitles[], int mNumbOfTabsumb, Activity a) {
super(fm);
this.mainActivity = a;
this.Titles = mTitles;
this.NumbOfTabs = mNumbOfTabsumb;
}
//This method return the fragment for the every position in the View Pager
@Override
public Fragment getItem(int position) {
switch (position) {
case 0:
MainFragment tab1 = new MainFragment();
return tab1;
case 1:
InventoryFragment tab2 = new InventoryFragment();
return tab2;
case 2:
AttributesFragment tab3 = new AttributesFragment();
return tab3;
}
return null;
}
// This method return the titles for the Tabs in the Tab Strip
@Override
public CharSequence getPageTitle(int position) {
return Titles[position];
}
// This method return the Number of tabs for the tabs Strip
@Override
public int getCount() {
return NumbOfTabs;
}
}
以及我的一个片段的例子（此时它们基本相同）：
public class MainFragment extends Fragment implements RetrieveData.Callback {
TextView mResult;
RetrieveData mAsyncRetriever;
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View v =inflater.inflate(R.layout.main_tab,container,false);
mResult = (TextView)v.findViewById(R.id.txtRoomDescription);
return v;
}
@Override
public void onResume() {
// Keep a reference to the AsyncTask so we can properly
// cancel it when our lifecycle events dictate so.
super.onResume();
mAsyncRetriever = new RetrieveData(this);
//mAsyncRetriever.execute("get_room.php","1");
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
mAsyncRetriever.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, "get_room.php","1");
else
mAsyncRetriever.execute("get_room.php", "1");
}
@Override
public void onPause() {
super.onPause();
// If we have a pending data load going on, kill it.
if (mAsyncRetriever != null) {
mAsyncRetriever.cancel(true);
mAsyncRetriever = null;
}
}
@Override
public void onDataLoaded(String[] result) {
// Only pulling the first result provided
mResult.setText(result[0]);
// The RetrieveData is done, get rid of our ref
mAsyncRetriever = null;
}
}
最后，我的RetrieveData班级：
public class RetrieveData extends AsyncTask<String, String, String[]> {
// provide results via interface
public interface Callback {
public void onDataLoaded(String[] result);
}
private Callback mCb;
public RetrieveData(Callback cb) {
mCb = cb;
}
protected String[] doInBackground(String... urls) {
String result = "";
String[] op = new String[2];// "";
op[0] = "";
op[1] = "";
ArrayList<NameValuePair> nameValuePairs = new ArrayList<>();
nameValuePairs.add(new BasicNameValuePair("id","1"));
try {
String postString = "/scripts/" + urls[0];
if (urls[0] == "get_room.php")
postString += "?room_id=" + urls[1];
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(postString);
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
InputStream is = entity.getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(is, "iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
//is.close();
result += sb.toString();
JSONArray jArray = new JSONArray(result);
for (int i = 0; i < jArray.length(); ++i) {
JSONObject json_data = jArray.getJSONObject(i);
//Log.i("info", "id: " + json_data.getInt("id") +
// "name: " + json_data.getString("name") +
// "desc: " + json_data.getString("desc")
//);
if (urls[0] == "get_room.php") {
op[0] += "id [" + json_data.getInt("id") + "]\n" +
"name [" + json_data.getString("name") + "]\n" +
"desc [" + json_data.getString("desc") + "]\n";
} else if (urls[0] == "get_inventory.php") {
op[0] += "id [" + json_data.getInt("id") + "]\n" +
"item name [" + json_data.getString("name") + "]\n" +
"item description [" + json_data.getString("description") + "]\n\n";
} else {
op[0] += "id [" + json_data.getInt("id") + "]\n" +
"username [" + json_data.getString("username") + "]\n" +
"status [" + json_data.getString("status") + "]\n";
}
//System.out.println(op);
}
} catch (Exception e) {
System.out.println("Error: " + e.toString());
}
return op;
}
@Override
protected void onPostExecute(String[] result) {
// update textbox
mCb.onDataLoaded(result);
return;
}