我在尝试编译应用程序时仍然遇到相同的错误，应用程序必须在列表组中显示一个问题，并在每个组的子项中显示5个图像。我认为错误可能在上下文中。
MainActivity.java
public class QuestionsFragment extends Fragment {
ExpandableListAdapter listAdapter;
ExpandableListView expListView;
List<String> listDataHeader;
HashMap<String, List<Integer>> listDataChild;
//private ArrayAdapter<String> mQuestionAdapter;
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.questions_fragment, container, false);
//Get the ListView
expListView = (ExpandableListView) rootView.findViewById(R.id.list_view);
//Prepare ListData
prepareListData();
listAdapter = new ExpandableListAdapter(QuestionsFragment.this.getActivity().getApplicationContext(), listDataHeader, listDataChild);
expListView.setAdapter((android.widget.ExpandableListAdapter) listAdapter);
// Inflate the layout for this fragment
return rootView;
}
/*
* Preparing the list data
*/
private void prepareListData() {
listDataHeader = new ArrayList<String>();
listDataChild = new HashMap<String, List<Integer>>();
// Adding child data
listDataHeader.add("Question 1");
listDataHeader.add("Question 2");
listDataHeader.add("Question 3");
// Adding child data
List<Integer> emoticons = new ArrayList<Integer>();
emoticons.add(R.drawable.bad);
emoticons.add(R.drawable.bad2);
emoticons.add(R.drawable.normal);
emoticons.add(R.drawable.good);
emoticons.add(R.drawable.excelent);
listDataChild.put(listDataHeader.get(0), emoticons); // Header, Child data
listDataChild.put(listDataHeader.get(1), emoticons);
listDataChild.put(listDataHeader.get(2), emoticons);
}
}
QuestionsFragment.java
public class ExpandableListAdapter {
private Context _context;
private List<String> _listDataHeader; // header titles
// child data in format of header title, child title
private HashMap<String, List<Integer>> _listDataChild;
public ExpandableListAdapter(Context context, List<String> listDataHeader,
HashMap<String, List<Integer>> listChildData) {
this._context = context;
this._listDataHeader = listDataHeader;
this._listDataChild = listChildData;
}
public Object getChild(int groupPosition, int childPosititon) {
return this._listDataChild.get(this._listDataHeader.get(groupPosition))
.get(childPosititon);
}
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
}
public View getChildView(int groupPosition, final int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {
//final String childText = (String) getChild(groupPosition, childPosition);
if (convertView == null) {
LayoutInflater infalInflater = (LayoutInflater) this._context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.emoticons_question_list_item, null);
}
ImageView lblListChild = (ImageView) convertView
.findViewById(R.id.image_bad);
ImageView lblListChild2 = (ImageView) convertView
.findViewById(R.id.image_bad2);
ImageView lblListNormal = (ImageView) convertView
.findViewById(R.id.image_normal);
ImageView lblListGood = (ImageView) convertView
.findViewById(R.id.image_good);
ImageView lblListExcelent = (ImageView) convertView
.findViewById(R.id.image_excelent);
TextView txtListChild = (TextView) convertView
.findViewById(R.id.question_list_item_textview);
return convertView;
}
public int getChildrenCount(int groupPosition) {
return this._listDataChild.get(this._listDataHeader.get(groupPosition))
.size();
}
public Object getGroup(int groupPosition) {
return this._listDataHeader.get(groupPosition);
}
public int getGroupCount() {
return this._listDataHeader.size();
}
public long getGroupId(int groupPosition) {
return groupPosition;
}
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
String headerTitle = (String) getGroup(groupPosition);
if (convertView == null) {
LayoutInflater infalInflater = (LayoutInflater) this._context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.question_list_item, null);
}
TextView txtListGroup = (TextView) convertView
.findViewById(R.id.question_list_item_textview);
txtListGroup.setText(headerTitle);
return convertView;
}
public boolean hasStableIds() {
return false;
}
public boolean isChildSelectable(int groupPosition, int childPosition) {
return true;
}
}
ExpandableListAdapter.java
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/white">
<ExpandableListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:divider="@drawable/list_divider"
android:dividerHeight="1dp"
android:id="@+id/list_view">
</ExpandableListView>
</FrameLayout>
questions_fragment.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/lists"
android:background="@color/light_gray"
android:padding="4dp">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:minHeight="10dp"
android:gravity="center"
android:id="@+id/question_list_item_textview"
android:textColor="@color/black"
android:textSize="21dp">
</TextView>
question_list_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TableLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="30dp"
android:stretchColumns="*">
<!-- android:padding="2dp"> -->
<TableRow>
<ImageView
android:layout_height="55dp"
android:layout_width="55dp"
android:id="@+id/image_bad"/>
<ImageView
android:layout_height="55dp"
android:layout_width="55dp"
android:id="@+id/image_bad2"/>
<ImageView
android:layout_height="55dp"
android:layout_width="55dp"
android:id="@+id/image_normal"/>
<ImageView
android:layout_height="55dp"
android:layout_width="55dp"
android:id="@+id/image_good"/>
<ImageView
android:layout_height="55dp"
android:layout_width="55dp"
android:src="@+id/image_excelent"/>
</TableRow>
</TableLayout>
</LinearLayout>
emoticons_question_list_item.xml
java.lang.RuntimeException: Unable to start activity ComponentInfo{br.ind.uptech.princessfeedback/br.ind.uptech.princessfeedback.MainActivity}: java.lang.ClassCastException: br.ind.uptech.princessfeedback.ExpandableListAdapter cannot be cast to android.widget.ExpandableListAdapter
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3139)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3238)
at android.app.ActivityThread.access$1000(ActivityThread.java:197)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1681)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:6862)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199)
Caused by: java.lang.ClassCastException: br.ind.uptech.princessfeedback.ExpandableListAdapter cannot be cast to android.widget.ExpandableListAdapter
at br.ind.uptech.princessfeedback.QuestionsFragment.onCreateView(QuestionsFragment.java:44)
at android.app.Fragment.performCreateView(Fragment.java:2114)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:904)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1082)
at android.app.BackStackRecord.run(BackStackRecord.java:834)
at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1467)
at android.app.Activity.performStart(Activity.java:6573)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3102)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3238)
at android.app.ActivityThread.access$1000(ActivityThread.java:197)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1681)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:6862)
at java.lang.reflect.Method.invoke(Native Method)
这是它返回的错误：
{{1}}
非常感谢！
答案 0 :(得分：0)
修改
expListView.setAdapter((android.widget.ExpandableListAdapter) listAdapter);
到
expListView.setAdapter(listAdapter);