我正在使用兼容性库 v4+。按照其他线程和开发指南，我正在尝试创建一个片段，该片段从创建它的活动中调用进度对话框。该方法使用在 AsyncTask 的预执行中显示的DialogFragment，并在执行后关闭（删除）。结果我没有得到任何对话框......好吧，事实是对话框在thread.sleep结束时只显示了几分之一秒。
有人能告诉我哪里错了吗？
我在这里有我的片段：
public class GroupsDetailsFragment extends BaseFragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// Inflate the layout for this fragment
View v = inflater.inflate(R.layout.fragment_groups_details, container, false);
return v;
}
@Override
public void onStart() {
// TODO Auto-generated method stub
super.onStart();
loadPage();
}
public void loadPage() {
Log.i(TAG, "loadPage");
new LoadPageTask(getBaseActivity()).execute();
}
public void executeLoadPagePreExecution() {Log.i(TAG, "executeLoadPagePreExecution"); }
public void executeLoadPageInBackground() {Log.i(TAG, "executeLoadPageInBackground"); }
public void executeLoadPagePostExecution() {try {
Thread.sleep(5000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}Log.i(TAG, "executeRefreshPostExecution"); }
protected class LoadPageTask extends AsyncTask<Void, Void, String> {
private Context context;
public LoadPageTask(Context context) {
super();
this.context = context;
}
@Override
protected void onPreExecute() {
// before the network request begins, show a progress indicator
getBaseActivity().showLoadingProgressDialog(context);
executeLoadPagePreExecution();
}
@Override
protected String doInBackground(Void... params) {
String result = executeLoadPage();
Log.i(TAG, "error message result: " + result);
return result;
}
// Returns null if Everything is OK. Error Message if any problem.
private String executeLoadPage() {
try {
executeLoadPageInBackground();
return null;
} catch (Exception e){
Log.w(TAG, e.getMessage(), e);
return(e.getMessage());
}
}
@Override
protected void onPostExecute(String message) {
executeLoadPagePostExecution();
getBaseActivity().dismissProgressDialog();
if (message!=null){
Utility.showMessageAlertDialog(message, context);
}
}
}
}
而 ProgressDialogFragment 是显示片段的 FragmentActivity 的内部类：
public static class ProgressDialogFragment extends DialogFragment {
public static ProgressDialogFragment newInstance(String title, String message) {
ProgressDialogFragment fragment = new ProgressDialogFragment();
Bundle args = new Bundle();
args.putString("title", title);
args.putString("message", message);
fragment.setArguments(args);
return fragment;
}
@Override
public ProgressDialog onCreateDialog(Bundle savedInstanceState) {
String title = getArguments().getString("title");
String message = getArguments().getString("message");
ProgressDialog progressDialog = new ProgressDialog(getActivity());
progressDialog.setTitle(title);
progressDialog.setMessage(message);
progressDialog.show();
return progressDialog;
}
}
public void showProgressDialog(String title, String message) {
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
Fragment prev = fragmentManager.findFragmentByTag("progress dialog");
if(prev!=null) {
fragmentTransaction.remove(prev);
}
fragmentTransaction.addToBackStack(null);
DialogFragment newFragment = ProgressDialogFragment.newInstance(title, message);
newFragment.show(fragmentManager, "progress dialog");
//fragmentTransaction.commit();
}
public void removeProgressDialog() {
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
Fragment prev = fragmentManager.findFragmentByTag("progress dialog");
if(prev!=null) {
fragmentTransaction.remove(prev);
}
fragmentTransaction.commit();
}