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我正在使用Android片段和viewpager安裝程序。基本上有5個標籤可以滑過。Android上的「內容視圖尚未創建」片段
5中的4個包含由MySQL表填充的ListFragments;這是在AsyncTask內完成的。當我刷卡很快我有時會收到此錯誤：
09-01 07:54:01.243: E/AndroidRuntime(19706): FATAL EXCEPTION: main
09-01 07:54:01.243: E/AndroidRuntime(19706): java.lang.IllegalStateException: Content view not yet created
09-01 07:54:01.243: E/AndroidRuntime(19706): at android.support.v4.app.ListFragment.ensureList(ListFragment.java:328)
09-01 07:54:01.243: E/AndroidRuntime(19706): at android.support.v4.app.ListFragment.getListView(ListFragment.java:222)
09-01 07:54:01.243: E/AndroidRuntime(19706): at com.---.---.MasterCat$TopFrag$TopTask.onPostExecute(MasterCat.java:570)
09-01 07:54:01.243: E/AndroidRuntime(19706): at com.---.---.MasterCat$TopFrag$TopTask.onPostExecute(MasterCat.java:1)
09-01 07:54:01.243: E/AndroidRuntime(19706): at android.os.AsyncTask.finish(AsyncTask.java:631)
09-01 07:54:01.243: E/AndroidRuntime(19706): at android.os.AsyncTask.access$600(AsyncTask.java:177)
09-01 07:54:01.243: E/AndroidRuntime(19706): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
09-01 07:54:01.243: E/AndroidRuntime(19706): at android.os.Handler.dispatchMessage(Handler.java:99)
09-01 07:54:01.243: E/AndroidRuntime(19706): at android.os.Looper.loop(Looper.java:137)
09-01 07:54:01.243: E/AndroidRuntime(19706): at android.app.ActivityThread.main(ActivityThread.java:4928)
09-01 07:54:01.243: E/AndroidRuntime(19706): at java.lang.reflect.Method.invokeNative(Native Method)
09-01 07:54:01.243: E/AndroidRuntime(19706): at java.lang.reflect.Method.invoke(Method.java:511)
09-01 07:54:01.243: E/AndroidRuntime(19706): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
09-01 07:54:01.243: E/AndroidRuntime(19706): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:558)
09-01 07:54:01.243: E/AndroidRuntime(19706): at dalvik.system.NativeStart.main(Native Method)
我已經intentionly不使用ProgressDialog，因爲它使刷卡口吃了不少。
所以，我有兩個選擇，我需要幫助兩種方式：
如何避免這個錯誤，並保持清爽列表即使刷卡。
或者一旦加載了5個片段，關閉'刷新時刷新'。換句話說，除非您退出活動並返回，否則列表將保持不變。
我寧願選擇＃1。請讓我知道你需要看看代碼：
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_layout);
mSectionsPagerAdapter = new SectionsPagerAdapter(
getSupportFragmentManager());
final ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
mViewPager = (ViewPager) findViewById(R.id.viewpager);
mViewPager.setAdapter(mSectionsPagerAdapter);
mViewPager
.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
@Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
actionBar.addTab(actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
}
public void onTabUnselected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
}
@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
super.onSaveInstanceState(savedInstanceState);
}
@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
}
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {
mViewPager.setCurrentItem(tab.getPosition());
}
public void onTabReselected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
}
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
Fragment f = null;
switch (position) {
case 0: {
f = new MasterFrag();
Bundle args = new Bundle();
f.setArguments(args);
break;
}
case 1: {
f = new FeaturedFrag();
Bundle args = new Bundle();
f.setArguments(args);
break;
}
case 4: {
f = new TopFrag();
Bundle args = new Bundle();
f.setArguments(args);
break;
}
case 3: {
f = new NewFrag();
Bundle args = new Bundle();
f.setArguments(args);
break;
}
case 2: {
f = new TrendFrag();
Bundle args = new Bundle();
f.setArguments(args);
break;
}
default:
throw new IllegalArgumentException("not this many fragments: "
+ position);
}
return f;
}
此外，在logcat的參考線570涉及一種getListView（）的的AsyncTask裏面這是上面沒有顯示一個ListFragment內。
編輯：
添加5個片段之一 - 一個在logcat的引用 - 「TopFrag」
class TopTask extends AsyncTask<String, String, Void> {
InputStream is = null;
String result = "";
@Override
protected Void doInBackground(String... params) {
String url_select = "http://www.---.com/---/---.php";
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url_select);
ArrayList<NameValuePair> param = new ArrayList<NameValuePair>();
param.add(new BasicNameValuePair("Top", "Top"));
try {
httpPost.setEntity(new UrlEncodedFormEntity(param));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
// read content
is = httpEntity.getContent();
} catch (Exception e) {
Log.e("log_tag", "Error in http connection " + e.toString());
}
try {
BufferedReader br = new BufferedReader(
new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line = "";
while ((line = br.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result = sb.toString();
} catch (Exception e) {
// TODO: handle exception
Log.e("log_tag", "Error converting result " + e.toString());
}
return null;
}
protected void onPostExecute(Void v) {
String item, cat;
try {
JSONArray jArray = new JSONArray(result);
JSONObject json_data = null;
for (int i = 0; i < jArray.length(); i++) {
json_data = jArray.getJSONObject(i);
item = json_data.getString("item");
cat = json_data.getString("category");
items.add(item);
cats.add(cat);
}
} catch (JSONException e1) {
Toast.makeText(getActivity(), "No Top Items Found",
Toast.LENGTH_LONG).show();
} catch (ParseException e1) {
e1.printStackTrace();
}
ListView listView;
listView = getListView();
listView.setTextFilterEnabled(true);
listView.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> arg0, View arg1,
int arg2, long id) {
// edit
}
});
MasterCatObject[] mco = new MasterCatObject[items.size()];
int index = 0;
for (@SuppressWarnings("unused")
String i : items) {
mco[index] = new MasterCatObject(items.get(index),
cats.get(index));
index++;
}
adapter = new AllTimeAdapter(getActivity(), mco);
setListAdapter(adapter);
}
}
}
我正在通過普通的'getListView（）'在PostExecute中獲取'ListView' - 將它放在OnActivityCreated中會更好嗎？ – KickingLettuce
'OnActivityCreated'應該可以工作，但是在調用'super'之後我會把它放在'onCreateView'中，因爲這肯定是一個你可以確定它在創建'ListView'時被調用的地方。 – zapl
標記正確;我已經可以看到事情更加穩定。 – KickingLettuce