所以我是Android应用程序写作的新手,我正在努力开发一个练习应用程序,我希望以后可以转化为某些东西。在我决定尝试将webview添加到其中一个之前,我在操作栏中有3个选项卡运行正常。现在它崩溃了IllegalStateException。由于我现在对机器人知之甚少,我似乎无法弄清楚出了什么问题。
主要活动:
private ViewPager viewPager;
private TabsPagerAdapter mAdapter;
private ActionBar actionBar;
private String[] tabs = { "Web", "Facebook", "Twitter" };
@SuppressLint("NewApi")
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Initialization
viewPager = (ViewPager) findViewById(R.id.pager);
actionBar = getActionBar();
mAdapter = new TabsPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(mAdapter);
actionBar.setHomeButtonEnabled(false);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Adding Tabs
for (String tab_name : tabs)
{
actionBar.addTab(actionBar.newTab().setText(tab_name).setTabListener(this));
}
/**
* on swiping the viewpager make respective tab selected
* */
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener()
{
@Override
public void onPageSelected(int position)
{
// on changing the page
// make respected tab selected
actionBar.setSelectedNavigationItem(position);
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2)
{
}
@Override
public void onPageScrollStateChanged(int arg0)
{
}
});
}
@Override
public void onTabReselected(Tab tab, FragmentTransaction ft)
{
}
@Override
public void onTabSelected(Tab tab, FragmentTransaction ft)
{
// on tab selected
// show respected fragment view
viewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(Tab tab, FragmentTransaction ft)
{
}
使用webview的WebFragment:
public class WebFragment extends Fragment
{
private String url = getString(R.string.website);
//@Override
//public void onActivityCreated(Bundle savedInstanceState)
//{
//super.onActivityCreated(savedInstanceState);
//}
@SuppressLint("SetJavaScriptEnabled")
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState)
{
View rootView = inflater.inflate(R.layout.web_fragment, container, false);
WebView tolerableWebView = (WebView) getView().findViewById(R.id.webview);
tolerableWebView.getSettings().setJavaScriptEnabled(true);
tolerableWebView.loadUrl(url);
return rootView;
}
}
TabsPagerAdapter:
public class TabsPagerAdapter extends FragmentPagerAdapter
{
public TabsPagerAdapter(FragmentManager fm)
{
super(fm);
}
@Override
public Fragment getItem(int index)
{
switch (index) {
case 0:
// Top Rated fragment activity
return new WebFragment();
case 1:
// Games fragment activity
return new FacebookFragment();
case 2:
// Movies fragment activity
return new TwitterFragment();
}
return null;
}
@Override
public int getCount()
{
// get item count - equal to number of tabs
return 3;
}
}
webfragment xml
<?xml version="1.0" encoding="utf-8"?>
<WebView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/webview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
</WebView>
主要活动xml:
<android.support.v4.view.ViewPager
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
任何帮助都会很棒!感谢
答案 0 :(得分:87)
通常,在Fragment不再附加到Activity后尝试执行工作时会出现该错误。在触发IllegalStateException的回调中,添加对isAdded的检查:http://developer.android.com/reference/android/app/Fragment.html#isAdded()
if(!isAdded()) {
return;
}