我需要创建文件资源管理器可扩展视图。互联网上有很多关于文件浏览器的例子，但我们无法访问文件夹中的孩子。我尝试通过扩展BaseExpandableListAdapter来开发cunstome适配器。但是setOnClickListener（）不起作用。有没有人建议这个或任何其他解决方案使文件探索访问孩子的孩子？
这是我的MainActivity：
public class MainActivity extends ExpandableListActivity {
private ArrayList<String> parentItems = new ArrayList<String>();
private ArrayList<Object> childItems = new ArrayList<Object>();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ExpandableListView expandableList = getExpandableListView();
expandableList.setDividerHeight(2);
expandableList.setGroupIndicator(null);
expandableList.setClickable(true);
DirManager.getDir(Environment.getExternalStorageDirectory()+"/HomeDir");
parentItems=Repository.getParentItems();
childItems=Repository.getChildItems();
MyExpandableAdapter adapter = new MyExpandableAdapter(parentItems, childItems);
adapter.setInflater((LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE), this);
expandableList.setAdapter(adapter);
expandableList.setOnChildClickListener(this);
}
}
存储库类：
public class Repository {
private static ArrayList<String> parentItems = new ArrayList<String>();
private static ArrayList<Object> childItems = new ArrayList<Object>();
public static ArrayList<String> getParentItems() {
return parentItems;
}
public static void setParentItems(ArrayList<String> parentItems) {
Repository.parentItems = parentItems;
}
public static ArrayList<Object> getChildItems() {
return childItems;
}
public static void setChildItems(ArrayList<Object> childItems) {
Repository.childItems = childItems;
}
}
DirManager类：
public class DirManager {
private static ArrayList<String> parentItems = new ArrayList<String>();
private static ArrayList<Object> childItems = new ArrayList<Object>();
public static void getDir(String dirPath) {
System.out.println(dirPath);
File f = new File(dirPath);
File[] files = f.listFiles();
if(!dirPath.equals(Environment.getExternalStorageDirectory()+"/HomeDir"))
{
System.out.println("Test 4");
parentItems.add(Environment.getExternalStorageDirectory()+"/HomeDir");
parentItems.add("../");
}
for(int i=0; i < files.length; i++)
{
File file = files[i];
System.out.println("Test 5");
if(file.isDirectory())
parentItems.add(file.getName() + "/");
else
parentItems.add(file.getName());
System.out.println("Test 6");
getChild(file);
}
Repository.setParentItems(parentItems);
Repository.setChildItems(childItems);
}
public static void getChild(File f) {
System.out.println("Test 7");
File[] files = f.listFiles();
for(int i=0; i < files.length; i++)
{
System.out.println("Test 8");
File file = files[i];
if(file.isDirectory())
parentItems.add(file.getName() + "/");
else
parentItems.add(file.getName());
System.out.println("Test 9");
childItems.add(file);
}
}
MyExpandableAdapter类：
public class MyExpandableAdapter extends BaseExpandableListAdapter {
private Activity activity;
private ArrayList<Object> childtems;
private LayoutInflater inflater;
private ArrayList<String> parentItems, child;
public MyExpandableAdapter(ArrayList<String> parents, ArrayList<Object> childern) {
this.parentItems = parents;
this.childtems = childern;
}
public void setInflater(LayoutInflater inflater, Activity activity) {
this.inflater = inflater;
this.activity = activity;
}
@SuppressWarnings("unchecked")
@Override
public View getChildView(int groupPosition, final int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
child = (ArrayList<String>) childtems.get(groupPosition);
TextView textView = null;
if (convertView == null) {
convertView = inflater.inflate(R.layout.group, null);
}
textView = (TextView) convertView.findViewById(R.id.textView1);
textView.setText(child.get(childPosition));
convertView.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View view) {
Toast.makeText(activity, child.get(childPosition),
Toast.LENGTH_SHORT).show();
}
});
return convertView;
}
@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
if (convertView == null) {
convertView = inflater.inflate(R.layout.row, null);
}
((CheckedTextView) convertView).setText(parentItems.get(groupPosition));
((CheckedTextView) convertView).setChecked(isExpanded);
return convertView;
}
@Override
public Object getChild(int groupPosition, int childPosition) {
return null;
}
@Override
public long getChildId(int groupPosition, int childPosition) {
return 0;
}
@Override
public int getChildrenCount(int groupPosition) {
return ((ArrayList<String>) childtems.get(groupPosition)).size();
//return 2;
}
@Override
public Object getGroup(int groupPosition) {
return null;
}
@Override
public int getGroupCount() {
return parentItems.size();
}
@Override
public void onGroupCollapsed(int groupPosition) {
super.onGroupCollapsed(groupPosition);
}
@Override
public void onGroupExpanded(int groupPosition) {
super.onGroupExpanded(groupPosition);
}
@Override
public long getGroupId(int groupPosition) {
return 0;
}
@Override
public boolean hasStableIds() {
return false;
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
return false;
}
}
这是我得到的例外。
12-23 09:18:50.813: D/AndroidRuntime(18501): Shutting down VM 12-23 09:18:50.813: W/dalvikvm(18501): threadid=1: thread exiting with uncaught exception (group=0x410f32a0) 12-23 09:18:50.813: E/AndroidRuntime(18501): FATAL EXCEPTION: main 12-23 09:18:50.813: E/AndroidRuntime(18501): java.lang.ClassCastException: java.io.File cannot be cast to java.util.ArrayList 12-23 09:18:50.813: E/AndroidRuntime(18501): at com.example.androidexpandablefileexplorer.MyExpandableAdapter.getChildrenCount(MyExpandableAdapter.java:88) 12-23 09:18:50.813: E/AndroidRuntime(18501): at android.widget.ExpandableListConnector.refreshExpGroupMetadataList(ExpandableListConnector.java:568) 12-23 09:18:50.813: E/AndroidRuntime(18501): at android.widget.ExpandableListConnector.expandGroup(ExpandableListConnector.java:693) 12-23 09:18:50.813: E/AndroidRuntime(18501): at android.widget.ExpandableListView.handleItemClick(ExpandableListView.java:569) 12-23 09:18:50.813: E/AndroidRuntime(18501): at android.widget.ExpandableListView.performItemClick(ExpandableListView.java:522) 12-23 09:18:50.813: E/AndroidRuntime(18501): at android.widget.AbsListView$PerformClick.run(AbsListView.java:3067) 12-23 09:18:50.813: E/AndroidRuntime(18501): at android.widget.AbsListView$1.run(AbsListView.java:3963) 12-23 09:18:50.813: E/AndroidRuntime(18501): at android.os.Handler.handleCallback(Handler.java:615) 12-23 09:18:50.813: E/AndroidRuntime(18501): at android.os.Handler.dispatchMessage(Handler.java:92) 12-23 09:18:50.813: E/AndroidRuntime(18501): at android.os.Looper.loop(Looper.java:137) 12-23 09:18:50.813: E/AndroidRuntime(18501): at android.app.ActivityThread.main(ActivityThread.java:4898) 12-23 09:18:50.813: E/AndroidRuntime(18501): at java.lang.reflect.Method.invokeNative(Native Method) 12-23 09:18:50.813: E/AndroidRuntime(18501): at java.lang.reflect.Method.invoke(Method.java:511) 12-23 09:18:50.813: E/AndroidRuntime(18501): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1006) 12-23 09:18:50.813: E/AndroidRuntime(18501): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:773) 12-23 09:18:50.813: E/AndroidRuntime(18501): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：1)
您的对象childItems是ArrayList<Object>的一种类型，您正在将其转换为
ArrayList<String>
在这个方法
@Override
public int getChildrenCount(int groupPosition) {
return ((ArrayList<String>) childtems.get(groupPosition)).size();
}
使用以下方法重复此方法
@Override
public int getChildrenCount(int groupPosition) {
return ((ArrayList<Object>) childtems.get(groupPosition)).size();
}