编辑：修复了空例外。
尝试按照教程http://en.wikicode.org/index.php/Custom_ExpandableListView后，只有第1组标题显示没有子项。没有其他孩子的标题出现。为什么会被切断？
这是我的代码：
public class WelcomeFragment extends Fragment {
private UiLifecycleHelper uiHelper;
WebView mWebView;
TextView mName, mother, mlblName, mlblOther;
ImageView mImage;
LoginButton mAuthButton;
final static int AUTHORIZE_ACTIVITY_RESULT_CODE = 0;
String[] permissions = { "user_relationships" };
private ArrayList<String> groups;
private ArrayList<ArrayList<ArrayList<String>>> childs;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
View view = inflater.inflate(R.layout.fragment_welcome, null);
uiHelper = new UiLifecycleHelper(getActivity(), callback);
uiHelper.onCreate(savedInstanceState);
mName = (TextView) view.findViewById(R.id.txtName);
mother = (TextView) view.findViewById(R.id.txtOther);
mImage = (ImageView) view.findViewById(R.id.profilepicture);
mAuthButton = (LoginButton) view.findViewById(R.id.authButton);
// Get the data
Cursor c = getActivity().getContentResolver().query(StatusProvider.CONTENT_URI_USER, null, null, null, null);
if((c.moveToFirst()) && (c.getCount()>0))
{
mAuthButton.setVisibility(View.GONE);
mName.setText(c.getString(c.getColumnIndex(StatusData.KEY_USER_NAME))); //name
//new ImageDownloader().execute(c.getString(c.getColumnIndex(StatusData.KEY_USER_EMAIL)); //call asynctask
mother.setText(c.getString(c.getColumnIndex(StatusData.KEY_USER_OTHER))); //significant_other
AQuery aq = new AQuery(view);
//returns the cached file by url, returns null if url is not cached
File file = aq.getCachedFile(c.getString(c.getColumnIndex(StatusData.KEY_USER_PICTURE)));
if (file == null) {
Log.i("PROJECTCARUSO", "Did not find user picture on file" );
//load an image to an ImageView from network, cache image to file and memory
aq.id(R.id.profilepicture).image(c.getString(c.getColumnIndex(StatusData.KEY_USER_PICTURE)));
} else {
Log.i("PROJECTCARUSO", "Found user picture on file" );
Bitmap myBitmap = BitmapFactory.decodeFile(file.getAbsolutePath());
mImage.setImageBitmap(myBitmap);
}
Log.i("PROJECTCARUSO", "Found user information in database" );
} else {
mlblName = (TextView) view.findViewById(R.id.lblName);
mlblOther = (TextView) view.findViewById(R.id.lblOther);
//Hide everything
mName.setVisibility(View.GONE);
mother.setVisibility(View.GONE);
mImage.setVisibility(View.GONE);
mlblName.setVisibility(View.GONE);
mlblOther.setVisibility(View.GONE);
Log.i("PROJECTCARUSO", "Did not find user information in database" );
}
mAuthButton.setFragment(this);
mAuthButton.setReadPermissions(Arrays.asList("email"));
ExpandableListView l = (ExpandableListView) getActivity().findViewById(R.id.ExpandableListView01);
loadData();
myExpandableAdapter adapter = new myExpandableAdapter(getActivity(), groups, childs);
l.setAdapter(adapter);
return view;
}
public void refreshView(){
// Get the data
Cursor c = getActivity().getContentResolver().query(StatusProvider.CONTENT_URI_USER, null, null, null, null);
if((c.moveToFirst()) && (c.getCount()>0))
{
mAuthButton.setVisibility(View.GONE);
//Show everything
mName.setVisibility(View.VISIBLE);
mother.setVisibility(View.VISIBLE);
mImage.setVisibility(View.VISIBLE);
mlblName.setVisibility(View.VISIBLE);
mlblOther.setVisibility(View.VISIBLE);
mName.setText(c.getString(c.getColumnIndex(StatusData.KEY_USER_NAME))); //name
//new ImageDownloader().execute(c.getString(c.getColumnIndex(StatusData.KEY_USER_EMAIL)); //call asynctask
mother.setText(c.getString(c.getColumnIndex(StatusData.KEY_USER_OTHER))); //significant_other
AQuery aq = new AQuery(getActivity());
//returns the cached file by url, returns null if url is not cached
File file = aq.getCachedFile(c.getString(c.getColumnIndex(StatusData.KEY_USER_PICTURE)));
if (file == null) {
Log.i("PROJECTCARUSO", "Did not find user picture on file" );
//load an image to an ImageView from network, cache image to file and memory
aq.id(R.id.profilepicture).image(c.getString(c.getColumnIndex(StatusData.KEY_USER_PICTURE)));
} else {
Log.i("PROJECTCARUSO", "Found user picture on file" );
Bitmap myBitmap = BitmapFactory.decodeFile(file.getAbsolutePath());
mImage.setImageBitmap(myBitmap);
}
Log.i("PROJECTCARUSO", "Found user information in database" );
} else {
Log.i("PROJECTCARUSO", "Did not find user information in database" );
}
}
private void onSessionStateChange(Session session, SessionState state, Exception exception) {
if (state.isOpened()) {
// Request user data and show the results
Request.executeMeRequestAsync(session, new Request.GraphUserCallback() {
@Override
public void onCompleted(GraphUser user, Response response) {
if (user != null) {
Utility.userUID = user.getId();
final String name = user.getName();
final String fname = user.getFirstName();
final String username = user.getUsername();
final String email = (String) user.getProperty("email");
String picURL = null;
String significant_other = null;
try {
String inputLine = user.getProperty("significant_other").toString();
JSONObject json = new JSONObject(inputLine.toString());
significant_other = json.get("name").toString();
} catch (JSONException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
picURL = "http://graph.facebook.com/"+Utility.userUID+"/picture";
Log.i("PROJECTCARUSO", "Logged in...");
try{
ContentValues values = new ContentValues();
values.put(StatusData.KEY_USER_ROWID, Utility.userUID);
values.put(StatusData.KEY_USER_NAME, name);
values.put(StatusData.KEY_USER_FNAME, fname);
values.put(StatusData.KEY_USER_USERNAME, username);
values.put(StatusData.KEY_USER_EMAIL, email);
values.put(StatusData.KEY_USER_PICTURE, picURL);
values.put(StatusData.KEY_USER_OTHER, significant_other);
StatusData StatusData = new StatusData(getActivity());
StatusData.insertOrReplaceUser(values);
Log.i("PROJECTCARUSO", "Insert of facebook information was successfull ");
refreshView();
} catch (Exception e ) {
Log.i("PROJECTCARUSO", "Insert of facebook information was not successfull ");
}
}
}
});
} else if (state.isClosed()) {
Log.i("PROJECTCARUSO", "Logged out...");
Log.i("PROJECTCARUSO", "Exception: " + exception);
}
}
private Session.StatusCallback callback = new Session.StatusCallback() {
@Override
public void call(Session session, SessionState state, Exception exception) {
onSessionStateChange(session, state, exception);
}
};
@Override
public void onResume() {
super.onResume();
// For scenarios where the main activity is launched and user
// session is not null, the session state change notification
// may not be triggered. Trigger it if it's open/closed.
Session session = Session.getActiveSession();
if (session != null &&
(session.isOpened() || session.isClosed()) ) {
onSessionStateChange(session, session.getState(), null);
}
uiHelper.onResume();
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
uiHelper.onActivityResult(requestCode, resultCode, data);
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
uiHelper.onSaveInstanceState(outState);
}
public class myExpandableAdapter extends BaseExpandableListAdapter {
private ArrayList<String> groups;
private ArrayList<ArrayList<ArrayList<String>>> children;
private Context context;
public myExpandableAdapter(Context context, ArrayList<String> groups, ArrayList<ArrayList<ArrayList<String>>> children) {
this.context = context;
this.groups = groups;
this.children = childs;
}
@Override
public boolean areAllItemsEnabled()
{
return true;
}
@Override
public ArrayList<String> getChild(int groupPosition, int childPosition) {
return children.get(groupPosition).get(childPosition);
}
@Override
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
}
@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild,View convertView, ViewGroup parent) {
String child = (String) ((ArrayList<String>)getChild(groupPosition, childPosition)).get(0);
if (convertView == null) {
LayoutInflater infalInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.expandablelistview_child, null);
}
TextView childtxt = (TextView) convertView.findViewById(R.id.TextViewChild01);
childtxt.setText(child);
return convertView;
}
@Override
public int getChildrenCount(int groupPosition) {
return children.get(groupPosition).size();
}
@Override
public String getGroup(int groupPosition) {
return groups.get(groupPosition);
}
@Override
public int getGroupCount() {
return groups.size();
}
@Override
public long getGroupId(int groupPosition) {
return groupPosition;
}
@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
String group = (String) getGroup(groupPosition);
if (convertView == null) {
LayoutInflater infalInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.expandablelistview_group, null);
}
TextView grouptxt = (TextView) convertView.findViewById(R.id.TextViewGroup);
grouptxt.setText(group);
return convertView;
}
@Override
public boolean hasStableIds() {
return true;
}
@Override
public boolean isChildSelectable(int arg0, int arg1) {
return true;
}
}
private void loadData(){
groups= new ArrayList<String>();
childs= new ArrayList<ArrayList<ArrayList<String>>>();
groups.add("Group 1");
groups.add("Group 2");
groups.add("Group 3");
childs.add(new ArrayList<ArrayList<String>>());
childs.get(0).add(new ArrayList<String>());
childs.get(0).get(0).add("Child 1 group 1");
childs.get(0).add(new ArrayList<String>());
childs.get(0).get(1).add("Child 2 group 1");
childs.get(0).add(new ArrayList<String>());
childs.get(0).get(2).add("Child 3 group 1");
childs.add(new ArrayList<ArrayList<String>>());
childs.get(1).add(new ArrayList<String>());
childs.get(1).get(0).add("Child 1 group 2");
childs.get(1).add(new ArrayList<String>());
childs.get(1).get(1).add("Child 2 group 2");
childs.get(1).add(new ArrayList<String>());
childs.get(1).get(2).add("Child 3 group 2");
childs.add(new ArrayList<ArrayList<String>>());
childs.get(2).add(new ArrayList<String>());
childs.get(2).get(0).add("Child 1 group 3");
childs.get(2).add(new ArrayList<String>());
childs.get(2).get(1).add("Child 2 group 3");
childs.get(2).add(new ArrayList<String>());
childs.get(2).get(2).add("Child 3 group 3");
}
}
XML：
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:id="@+id/textView1"
android:layout_width="fill_parent"
android:layout_height="6dip"
android:layout_marginTop="20dp"
android:background="#ffcccccc"
android:textIsSelectable="false" />
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#ffcccccc" >
<ImageView
android:id="@+id/profilepicture"
android:layout_width="100sp"
android:layout_height="100sp"
android:layout_alignParentLeft="true"
android:contentDescription="@string/lblPicture"
android:src="@drawable/photofemale" />
<!-- Name -->
<TextView
android:id="@+id/txtName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/lblName"
android:layout_marginLeft="10dp"
android:layout_marginRight="20dp"
android:layout_toRightOf="@+id/profilepicture"
android:text="@string/txtname"
android:textAppearance="?android:attr/textAppearanceMedium" />
<!-- significant_other -->
<TextView
android:id="@+id/lblOther"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/txtName"
android:layout_below="@+id/txtName"
android:text="@string/lblother"
android:textAppearance="?android:attr/textAppearanceMedium" />
<!-- Logged in Credentials -->
<TextView
android:id="@+id/lblName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/txtName"
android:layout_below="@+id/textView1"
android:text="@string/lblname"
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="@+id/txtOther"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/lblOther"
android:layout_below="@+id/lblOther"
android:text="@string/txtother"
android:textAppearance="?android:attr/textAppearanceMedium" />
<!-- Logged in Credentials -->
<com.facebook.widget.LoginButton
android:id="@+id/authButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/textView1" />
</RelativeLayout>
<TextView
android:id="@+id/textView2"
android:layout_width="fill_parent"
android:layout_height="6dip"
android:layout_marginBottom="5dp"
android:background="#ffcccccc"
android:textIsSelectable="false" />
<ExpandableListView
android:id="@+id/ExpandableListView01"
android:layout_height="wrap_content"
android:layout_width="fill_parent"
>
</ExpandableListView>
</LinearLayout>
</ScrollView>
为了理智： expandablelistview_child.xml
<?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:background="#666666"
>
<TextView
android:id="@+id/TextViewChild01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="30px"
>
</TextView>
<TextView
android:id="@+id/TextViewChild02"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="10px"
>
</TextView>
<TextView
android:id="@+id/TextViewChild03"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="10px"
>
</TextView>
</LinearLayout>
expandablelistview_group.xml：
<?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"
>
<TextView
android:id="@+id/TextViewGroup"
android:layout_width="wrap_content"
android:layout_height="50px"
android:layout_marginLeft="50px"
android:gravity="center_vertical"
>
</TextView>
</LinearLayout>
答案 0 :(得分：1)
导致错误的原因有两种：
ExpandableListView01的元素ExpandableListView01的视图不属于ExpandableListView 在这种情况下，我的赌注是第一个原因。实际上，您正在调用活动上的getViewById()，该活动尚未加载布局。替换此行：
ExpandableListView l = (ExpandableListView) getActivity().findViewById(R.id.ExpandableListView01);
这一行：
ExpandableListView l = (ExpandableListView) view.findViewById(R.id.ExpandableListView01);