我正在使用 Android Sherlock,我正在尝试在 Android 中实现片段的经典示例:
http://developer.android.com/guide/topics/fundamentals/fragments.html
但是在TitlesFragment.java文件中出现错误,避免我的应用程序运行。我不知道为什么。
package com.android.fragmenttest;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.FragmentTransaction;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import com.actionbarsherlock.app.SherlockListFragment;
public class TitlesFragment extends SherlockListFragment {
boolean mDualPane;
int mCurCheckPosition = 0;
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
// Populate list with our static array of titles.
setListAdapter(new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, android.R.id.text1, Shakespeare.TITLES));
// Check to see if we have a frame in which to embed the details
// fragment directly in the containing UI.
View detailsFrame = getActivity().findViewById(R.id.details);
mDualPane = detailsFrame != null && detailsFrame.getVisibility() == View.VISIBLE;
if (savedInstanceState != null) {
// Restore last state for checked position.
mCurCheckPosition = savedInstanceState.getInt("curChoice", 0);
}
if (mDualPane) {
// In dual-pane mode, the list view highlights the selected item.
getListView().setChoiceMode(ListView.CHOICE_MODE_SINGLE);
// Make sure our UI is in the correct state.
showDetails(mCurCheckPosition);
}
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt("curChoice", mCurCheckPosition);
}
@Override
public void onListItemClick(ListView l, View v, int position, long id) {
showDetails(position);
}
// Helper function to show the details of a selected item, either by displaying a fragment in-place in the current UI, or starting a
// whole new activity in which it is displayed.
void showDetails(int index) {
mCurCheckPosition = index;
if (mDualPane) {
// We can display everything in-place with fragments, so update the list to highlight the selected item and show the data.
getListView().setItemChecked(index, true);
// Check what fragment is currently shown, replace if needed.
DetailsFragment details = (DetailsFragment) getFragmentManager().findFragmentById(R.id.details);
if (details == null || details.getShownIndex() != index) {
// Make new fragment to show this selection.
details = DetailsFragment.newInstance(index);
// Execute a transaction, replacing any existing fragment with this one inside the frame.
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.replace(R.id.details, details);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
ft.commit();
}
} else {
// Otherwise we need to launch a new activity to display the dialog fragment with selected text.
Intent intent = new Intent();
intent.setClass(getActivity(), DetailsActivity.class);
intent.putExtra("index", index);
startActivity(intent);
}
}
}
Eclipse 哭泣的台词是:
View detailsFrame = getActivity().findViewById(R.id.details);
和:
DetailsFragment details = (DetailsFragment) getFragmentManager().findFragmentById(R.id.details);
和:
ft.replace(R.id.details, details);
因此,R.id.details是问题所在。类DetailsFragment.java定义如下:
package com.android.fragmenttest;
import android.os.Bundle;
import android.util.TypedValue;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ScrollView;
import android.widget.TextView;
import com.actionbarsherlock.app.SherlockFragment;
public class DetailsFragment extends SherlockFragment {
// Create a new instance of DetailsFragment, initialized to show the text at 'index'.
public static DetailsFragment newInstance(int index) {
DetailsFragment f = new DetailsFragment();
// Supply index input as an argument.
Bundle args = new Bundle();
args.putInt("index", index);
f.setArguments(args);
return f;
}
public int getShownIndex() {
return getArguments().getInt("index", 0);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
if (container == null) {
// We have different layouts, and in one of them this fragment's containing frame doesn't exist. The fragment
// may still be created from its saved state, but there is no reason to try to create its view hierarchy because it
// won't be displayed. Note this is not needed -- we could just run the code below, where we would create and return
// the view hierarchy; it would just never be used.
return null;
}
ScrollView scroller = new ScrollView(getActivity());
TextView text = new TextView(getActivity());
int padding = (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 4, getActivity().getResources().getDisplayMetrics());
text.setPadding(padding, padding, padding, padding);
scroller.addView(text);
text.setText(Shakespeare.DIALOGUE[getShownIndex()]);
return scroller;
}
}
有谁知道为什么 Eclipse 不让这个片段示例编译?