我从本网站的另一篇文章中获取了一些示例 ExpandableListFragment 代码，并通过一个 xml 文件引用了它，我从我的 Main Activity 加载到一个片段中：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal">
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
android:name="salty.oaktreebrides.android.FAQ"
android:id="@+id/Fragment1"
android:layout_width="0px"
android:layout_weight="1"
android:layout_height="match_parent" />
</LinearLayout>
但是我无法（新手）确定我应该如何/在哪里设置光标以提供其中的数据。代码当前触发，但正如预期的那样，我得到了 Progress Circle Spinning，因为我没有提供任何数据。我有自己的数据访问层类，可以提供光标，只是不确定如何将所有部分放在一起。我最终想从片段中的 API Demo 重新创建 ExpandableList1.java 功能，并让源是来自 sqlite 的游标。我希望这段代码能在一定程度上满足这一要求。请帮忙。
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.support.v4.app.Fragment;
import android.view.ContextMenu;
import android.view.ContextMenu.ContextMenuInfo;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnCreateContextMenuListener;
import android.view.ViewGroup;
import android.view.animation.AnimationUtils;
import android.widget.AdapterView;
import android.widget.ExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.FrameLayout;
import android.widget.LinearLayout;
import android.widget.ListAdapter;
import android.widget.ProgressBar;
import android.widget.TextView;
public class ExpandableListFragment extends Fragment
implements OnCreateContextMenuListener,
ExpandableListView.OnChildClickListener, ExpandableListView.OnGroupCollapseListener,
ExpandableListView.OnGroupExpandListener
{
static final int INTERNAL_EMPTY_ID = 0x00ff0001;
static final int INTERNAL_PROGRESS_CONTAINER_ID = 0x00ff0002;
static final int INTERNAL_LIST_CONTAINER_ID = 0x00ff0003;
final private Handler mHandler = new Handler();
final private Runnable mRequestFocus = new Runnable() {
public void run() {
mExpandableList.focusableViewAvailable(mExpandableList);
}
};
final private AdapterView.OnItemClickListener mOnClickListener
= new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
onListItemClick((ExpandableListView)parent, v, position, id);
}
};
ExpandableListAdapter mAdapter;
ExpandableListView mExpandableList;
boolean mFinishedStart = false;
View mEmptyView;
TextView mStandardEmptyView;
View mProgressContainer;
View mExpandableListContainer;
CharSequence mEmptyText;
boolean mExpandableListShown;
public ExpandableListFragment() {
}
/**
* Provide default implementation to return a simple list view. Subclasses
* can override to replace with their own layout. If doing so, the
* returned view hierarchy <em>must</em> have a ListView whose id
* is {@link android.R.id#list android.R.id.list} and can optionally
* have a sibling view id {@link android.R.id#empty android.R.id.empty}
* that is to be shown when the list is empty.
*
* <p>If you are overriding this method with your own custom content,
* consider including the standard layout {@link android.R.layout#list_content}
* in your layout file, so that you continue to retain all of the standard
* behavior of ListFragment. In particular, this is currently the only
* way to have the built-in indeterminant progress state be shown.
*/
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final Context context = getActivity();
FrameLayout root = new FrameLayout(context);
// ------------------------------------------------------------------
LinearLayout pframe = new LinearLayout(context);
pframe.setId(INTERNAL_PROGRESS_CONTAINER_ID);
pframe.setOrientation(LinearLayout.VERTICAL);
pframe.setVisibility(View.GONE);
pframe.setGravity(Gravity.CENTER);
ProgressBar progress = new ProgressBar(context, null,
android.R.attr.progressBarStyleLarge);
pframe.addView(progress, new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
root.addView(pframe, new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));
// ------------------------------------------------------------------
FrameLayout lframe = new FrameLayout(context);
lframe.setId(INTERNAL_LIST_CONTAINER_ID);
TextView tv = new TextView(getActivity());
tv.setId(INTERNAL_EMPTY_ID);
tv.setGravity(Gravity.CENTER);
lframe.addView(tv, new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));
ExpandableListView lv = new ExpandableListView(getActivity());
lv.setId(android.R.id.list);
lv.setDrawSelectorOnTop(false);
lframe.addView(lv, new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));
root.addView(lframe, new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));
// ------------------------------------------------------------------
root.setLayoutParams(new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));
return root;
}
/**
* Attach to list view once the view hierarchy has been created.
*/
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
ensureList();
}
/**
* Detach from list view.
*/
@Override
public void onDestroyView() {
mHandler.removeCallbacks(mRequestFocus);
mExpandableList = null;
mExpandableListShown = false;
mEmptyView = mProgressContainer = mExpandableListContainer = null;
mStandardEmptyView = null;
super.onDestroyView();
}
/**
* This method will be called when an item in the list is selected.
* Subclasses should override. Subclasses can call
* getListView().getItemAtPosition(position) if they need to access the
* data associated with the selected item.
*
* @param l The ListView where the click happened
* @param v The view that was clicked within the ListView
* @param position The position of the view in the list
* @param id The row id of the item that was clicked
*/
public void onListItemClick(ExpandableListView l, View v, int position, long id) {
}
/**
* Provide the cursor for the list view.
*/
public void setListAdapter(ExpandableListAdapter adapter) {
boolean hadAdapter = mAdapter != null;
mAdapter = adapter;
if (mExpandableList != null) {
mExpandableList.setAdapter(adapter);
if (!mExpandableListShown && !hadAdapter) {
// The list was hidden, and previously didn't have an
// adapter. It is now time to show it.
setListShown(true, getView().getWindowToken() != null);
}
}
}
/**
* Set the currently selected list item to the specified
* position with the adapter's data
*
* @param position
*/
public void setSelection(int position) {
ensureList();
mExpandableList.setSelection(position);
}
/**
* Get the position of the currently selected list item.
*/
public int getSelectedItemPosition() {
ensureList();
return mExpandableList.getSelectedItemPosition();
}
/**
* Get the cursor row ID of the currently selected list item.
*/
public long getSelectedItemId() {
ensureList();
return mExpandableList.getSelectedItemId();
}
/**
* Get the activity's list view widget.
*/
public ExpandableListView getListView() {
ensureList();
return mExpandableList;
}
/**
* The default content for a ListFragment has a TextView that can
* be shown when the list is empty. If you would like to have it
* shown, call this method to supply the text it should use.
*/
public void setEmptyText(CharSequence text) {
ensureList();
if (mStandardEmptyView == null) {
throw new IllegalStateException("Can't be used with a custom content view");
}
mStandardEmptyView.setText(text);
if (mEmptyText == null) {
mExpandableList.setEmptyView(mStandardEmptyView);
}
mEmptyText = text;
}
/**
* Control whether the list is being displayed. You can make it not
* displayed if you are waiting for the initial data to show in it. During
* this time an indeterminant progress indicator will be shown instead.
*
* <p>Applications do not normally need to use this themselves. The default
* behavior of ListFragment is to start with the list not being shown, only
* showing it once an adapter is given with {@link #setListAdapter(ListAdapter)}.
* If the list at that point had not been shown, when it does get shown
* it will be do without the user ever seeing the hidden state.
*
* @param shown If true, the list view is shown; if false, the progress
* indicator. The initial value is true.
*/
public void setListShown(boolean shown) {
setListShown(shown, true);
}
/**
* Like {@link #setListShown(boolean)}, but no animation is used when
* transitioning from the previous state.
*/
public void setListShownNoAnimation(boolean shown) {
setListShown(shown, false);
}
/**
* Control whether the list is being displayed. You can make it not
* displayed if you are waiting for the initial data to show in it. During
* this time an indeterminant progress indicator will be shown instead.
*
* @param shown If true, the list view is shown; if false, the progress
* indicator. The initial value is true.
* @param animate If true, an animation will be used to transition to the
* new state.
*/
private void setListShown(boolean shown, boolean animate) {
ensureList();
if (mProgressContainer == null) {
throw new IllegalStateException("Can't be used with a custom content view");
}
if (mExpandableListShown == shown) {
return;
}
mExpandableListShown = shown;
if (shown) {
if (animate) {
mProgressContainer.startAnimation(AnimationUtils.loadAnimation(
getActivity(), android.R.anim.fade_out));
mExpandableListContainer.startAnimation(AnimationUtils.loadAnimation(
getActivity(), android.R.anim.fade_in));
} else {
mProgressContainer.clearAnimation();
mExpandableListContainer.clearAnimation();
}
mProgressContainer.setVisibility(View.GONE);
mExpandableListContainer.setVisibility(View.VISIBLE);
} else {
if (animate) {
mProgressContainer.startAnimation(AnimationUtils.loadAnimation(
getActivity(), android.R.anim.fade_in));
mExpandableListContainer.startAnimation(AnimationUtils.loadAnimation(
getActivity(), android.R.anim.fade_out));
} else {
mProgressContainer.clearAnimation();
mExpandableListContainer.clearAnimation();
}
mProgressContainer.setVisibility(View.VISIBLE);
mExpandableListContainer.setVisibility(View.GONE);
}
}
/**
* Get the ListAdapter associated with this activity's ListView.
*/
public ExpandableListAdapter getListAdapter() {
return mAdapter;
}
private void ensureList() {
if (mExpandableList != null) {
return;
}
View root = getView();
if (root == null) {
throw new IllegalStateException("Content view not yet created");
}
if (root instanceof ExpandableListView) {
mExpandableList = (ExpandableListView)root;
} else {
mStandardEmptyView = (TextView)root.findViewById(INTERNAL_EMPTY_ID);
if (mStandardEmptyView == null) {
mEmptyView = root.findViewById(android.R.id.empty);
} else {
mStandardEmptyView.setVisibility(View.GONE);
}
mProgressContainer = root.findViewById(INTERNAL_PROGRESS_CONTAINER_ID);
mExpandableListContainer = root.findViewById(INTERNAL_LIST_CONTAINER_ID);
View rawExpandableListView = root.findViewById(android.R.id.list);
if (!(rawExpandableListView instanceof ExpandableListView)) {
if (rawExpandableListView == null) {
throw new RuntimeException(
"Your content must have a ListView whose id attribute is " +
"'android.R.id.list'");
}
throw new RuntimeException(
"Content has view with id attribute 'android.R.id.list' "
+ "that is not a ListView class");
}
mExpandableList = (ExpandableListView)rawExpandableListView;
if (mEmptyView != null) {
mExpandableList.setEmptyView(mEmptyView);
} else if (mEmptyText != null) {
mStandardEmptyView.setText(mEmptyText);
mExpandableList.setEmptyView(mStandardEmptyView);
}
}
mExpandableListShown = true;
mExpandableList.setOnItemClickListener(mOnClickListener);
if (mAdapter != null) {
ExpandableListAdapter adapter = mAdapter;
mAdapter = null;
setListAdapter(adapter);
} else {
// We are starting without an adapter, so assume we won't
// have our data right away and start with the progress indicator.
if (mProgressContainer != null) {
setListShown(false, false);
}
}
mHandler.post(mRequestFocus);
}
/**
* Override this to populate the context menu when an item is long pressed. menuInfo
* will contain an {@link android.widget.ExpandableListView.ExpandableListContextMenuInfo}
* whose packedPosition is a packed position
* that should be used with {@link ExpandableListView#getPackedPositionType(long)} and
* the other similar methods.
* <p>
* {@inheritDoc}
*/
@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
}
/**
* Override this for receiving callbacks when a child has been clicked.
* <p>
* {@inheritDoc}
*/
public boolean onChildClick(ExpandableListView parent, View v, int groupPosition,
int childPosition, long id) {
return false;
}
/**
* Override this for receiving callbacks when a group has been collapsed.
*/
public void onGroupCollapse(int groupPosition) {
}
/**
* Override this for receiving callbacks when a group has been expanded.
*/
public void onGroupExpand(int groupPosition) {
}
// /**
// * Ensures the expandable list view has been created before Activity restores all
// * of the view states.
// *
// *@see Activity#onRestoreInstanceState(Bundle)
// */
// @Override
// protected void onRestoreInstanceState(Bundle state) {
// ensureList();
// super.onRestoreInstanceState(state);
// }
/**
* Updates the screen state (current list and other views) when the
* content changes.
*
* @see Activity#onContentChanged()
*/
public void onContentChanged() {
// super.onContentChanged();
View emptyView = getView().findViewById(android.R.id.empty);
mExpandableList = (ExpandableListView)getView().findViewById(android.R.id.list);
if (mExpandableList == null) {
throw new RuntimeException(
"Your content must have a ExpandableListView whose id attribute is " +
"'android.R.id.list'");
}
if (emptyView != null) {
mExpandableList.setEmptyView(emptyView);
}
mExpandableList.setOnChildClickListener(this);
mExpandableList.setOnGroupExpandListener(this);
mExpandableList.setOnGroupCollapseListener(this);
if (mFinishedStart) {
setListAdapter(mAdapter);
}
mFinishedStart = true;
}
/**
* Get the activity's expandable list view widget. This can be used to get the selection,
* set the selection, and many other useful functions.
*
* @see ExpandableListView
*/
public ExpandableListView getExpandableListView() {
ensureList();
return mExpandableList;
}
/**
* Get the ExpandableListAdapter associated with this activity's
* ExpandableListView.
*/
public ExpandableListAdapter getExpandableListAdapter() {
return mAdapter;
}
/**
* Gets the ID of the currently selected group or child.
*
* @return The ID of the currently selected group or child.
*/
public long getSelectedId() {
return mExpandableList.getSelectedId();
}
/**
* Gets the position (in packed position representation) of the currently
* selected group or child. Use
* {@link ExpandableListView#getPackedPositionType},
* {@link ExpandableListView#getPackedPositionGroup}, and
* {@link ExpandableListView#getPackedPositionChild} to unpack the returned
* packed position.
*
* @return A packed position representation containing the currently
* selected group or child's position and type.
*/
public long getSelectedPosition() {
return mExpandableList.getSelectedPosition();
}
/**
* Sets the selection to the specified child. If the child is in a collapsed
* group, the group will only be expanded and child subsequently selected if
* shouldExpandGroup is set to true, otherwise the method will return false.
*
* @param groupPosition The position of the group that contains the child.
* @param childPosition The position of the child within the group.
* @param shouldExpandGroup Whether the child's group should be expanded if
* it is collapsed.
* @return Whether the selection was successfully set on the child.
*/
public boolean setSelectedChild(int groupPosition, int childPosition, boolean shouldExpandGroup) {
return mExpandableList.setSelectedChild(groupPosition, childPosition, shouldExpandGroup);
}
/**
* Sets the selection to the specified group.
* @param groupPosition The position of the group that should be selected.
*/
public void setSelectedGroup(int groupPosition) {
mExpandableList.setSelectedGroup(groupPosition);
}
}