Android 旋转设备后,ListView不再可单击
我有一个包含两个片段的活动,一个片段使用适配器显示项目的Android 旋转设备后,ListView不再可单击,android,listview,android-fragments,android-activity,Android,Listview,Android Fragments,Android Activity,我有一个包含两个片段的活动,一个片段使用适配器显示项目的ListView,第二个片段在单击时显示特定列表项目的信息 一切正常,只是只要我旋转设备并重新创建活动,我的ListView就会乱七八糟,有时无法滚动或单击(没有单击动画,单击时不会发生任何事情) 有什么想法吗?我不想从清单中禁用配置更改,因为我知道这不是一个好的做法 活动代码: public class MainActivity extends FragmentActivity implements AppListFragment.App
ListView
,第二个片段在单击时显示特定列表项目的信息
一切正常,只是只要我旋转设备并重新创建活动,我的ListView就会乱七八糟,有时无法滚动或单击(没有单击动画,单击时不会发生任何事情)
有什么想法吗?我不想从清单中禁用配置更改,因为我知道这不是一个好的做法
活动代码:
public class MainActivity extends FragmentActivity implements AppListFragment.AppListFragmentCallback{
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
AppListFragment fragment = new AppListFragment();
fragment.setArguments(getIntent().getExtras());
fragment.setRetainInstance(true);
getSupportFragmentManager().beginTransaction().add(R.id.main_frame, fragment).commit();
}
@Override
public void onAppSelected(String app) {
AppDetailsFragment fragment = new AppDetailsFragment();
Bundle args = new Bundle();
args.putString(AppDetailsFragment.KEY_APP, app);
fragment.setArguments(args);
fragment.setRetainInstance(true);
getSupportFragmentManager().beginTransaction().replace(R.id.main_frame, fragment).addToBackStack(null).commit();
}
}
列表片段代码:
public class AppListFragment extends Fragment {
public interface AppListFragmentCallback {
void onAppSelected(String app);
}
private AppListFragmentCallback callback;
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
// This makes sure that the container activity has implemented
// the callback interface. If not, it throws an exception
try {
callback = (AppListFragmentCallback) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement AppListFragmentCallback");
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_app_list, container, false);
AppListAdapter adapter = new AppListAdapter();
ListView lv = (ListView)view.findViewById(R.id.view_app_list);
lv.setAdapter(adapter);
lv.setOnItemClickListener(new OnItemClickListener() {
@SuppressWarnings("rawtypes")
@Override
public void onItemClick(AdapterView parent, View view, int position, long id) {
callback.onAppSelected((String)parent.getAdapter().getItem(position));
}
});
return view;
}
}
适配器代码:
public class AppListAdapter extends BaseAdapter implements ListAdapter {
private ArrayList<String> apps;
public AppListAdapter() {
apps = new ArrayList<String>();
for (Integer i = 0; i < 50; i++)
{
apps.add(i.toString());
}
}
@Override
public int getCount() {
return apps.size();
}
@Override
public Object getItem(int position) {
return apps.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
TextView text = new TextView(parent.getContext());
text.setText("App number " + apps.get(position));
text.setPadding(10, 3, 10, 3);
text.setBackgroundResource(R.drawable.button_xml);
return text;
}
}
}好的,我在读了这篇文章后设法弄明白了: 显然,设置
fragment.setRetainInstance(true)
表示片段未被销毁,但活动已被销毁,并且在onCreate()
中创建片段的新实例,即使它未被销毁
在创建新片段之前,我通过编辑活动的onCreate()
来检查片段是否存在,从而解决了这个问题:
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
AppListFragment fragment = (AppListFragment)getSupportFragmentManager().findFragmentByTag(TAG_LIST_FRAGMENT);
if (fragment == null) {
fragment = new AppListFragment();
fragment.setRetainInstance(true);
fragment.setArguments(getIntent().getExtras());
getSupportFragmentManager().beginTransaction().add(R.id.main_frame, fragment, TAG_LIST_FRAGMENT).commit();
}
}
可能活动已重新创建,而视图未重新创建?让视图引用旧的活动(回调)?我不确定“视图”是什么意思,但如果你指的是片段,那么它肯定是相关的。见答案
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
AppListFragment fragment = (AppListFragment)getSupportFragmentManager().findFragmentByTag(TAG_LIST_FRAGMENT);
if (fragment == null) {
fragment = new AppListFragment();
fragment.setRetainInstance(true);
fragment.setArguments(getIntent().getExtras());
getSupportFragmentManager().beginTransaction().add(R.id.main_frame, fragment, TAG_LIST_FRAGMENT).commit();
}
}