在DialogFragment中使用ExpandableList
我本来想在ListFragment中使用ExpandableList， 几次尝试终告失败。 因此，我修改了练习方案，在一个DialogFragment中使用ExpandableListView, 运行成功了，不过相貌比较难看，特别是那个GroupIndicator图片，因被拉伸显得极其丑陋， 这个问题以后再解决吧。
1. 在layout中配置ExpandableListView
2. 源码中，显示ExpandableListView的代码
3. 自定义点击子项时的操作
完整的代码：
1. 在layout中配置ExpandableListView
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ExpandableListView
android:id="@+id/expandableList1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:groupIndicator="@drawable/collapsed"
>
</ExpandableListView>
</LinearLayout>
2. 源码中，显示ExpandableListView的代码
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
//找到layout资源中名为expandable_list.xml的文件
View v = inflater.inflate(R.layout.expandable_list, container, false);
//找到该xml文件中定义的ExpandableListView的ID。
lv = (ExpandableListView) v.findViewById(R.id.expandableList1);
Log.i(TAG, "lv is null:" + (lv==null?true:false));
//提取父组织的数据
mGroupsCursor = s.getListCursorByLevel(getActivity().getContentResolver(), 0);
getActivity().startManagingCursor(mGroupsCursor);
mGroupIdColumnIndex = mGroupsCursor.getColumnIndexOrThrow(AreaSQLiteHelper.COLUMN_ID);
// Set up our adapter
String s = getResources().getString(R.string.list_data_null);
// 根据点击的父组织ID，显示其子组织的数据
mAdapter = new ProvinceExpandableListAdapter(
mGroupsCursor,
getActivity(),
android.R.layout.simple_expandable_list_item_1,
android.R.layout.simple_expandable_list_item_1,
new String[] {AreaSQLiteHelper.COLUMN_NAMES}, // group title for group layouts
new int[] { android.R.id.text1 },
new String[] {AreaSQLiteHelper.COLUMN_NAMES}, // exercise title for child layouts
new int[] { android.R.id.text1}
);
lv.setAdapter(mAdapter);
// 配置子组织点击的事件监听器
lv.setOnChildClickListener(this);
return v;
}
// extending SimpleCursorTreeAdapter
class ProvinceExpandableListAdapter extends SimpleCursorTreeAdapter {
public ProvinceExpandableListAdapter(Cursor cursor, Context context,
int groupLayout, int childLayout, String[] groupFrom,
int[] groupTo, String[] childrenFrom, int[] childrenTo) {
super(context, cursor, groupLayout, groupFrom, groupTo,
childLayout, childrenFrom, childrenTo);
}
// returns cursor with subitems for given group cursor
@Override
protected Cursor getChildrenCursor(Cursor groupCursor) {
int _countryId = groupCursor.getInt(groupCursor.getColumnIndexOrThrow(AreaSQLiteHelper.COLUMN_ID));
Cursor provinceCursor = s.getListCursorByParentId(getActivity().getContentResolver(), _countryId);
getActivity().startManagingCursor(provinceCursor);
return provinceCursor;
}
// 需要配置子组织可选择
@Override
public boolean isChildSelectable(int groupPosition,
int childPosition) {
return true;
}
}
3. 自定义点击子项时的操作
@Override // 该 class必须要执行ExpandableListView.OnChildClickListener的接口
public boolean onChildClick(ExpandableListView parent, View v,
int groupPosition, int childPosition, long id) {
Log.i(TAG,"groupPosition=" + groupPosition + ", childPosition=" + childPosition + ", id=" + id);
//此处实现的功能是：根据子组织的ID，动态刷新列表内容，并关闭此DIALOG
CityListFragment list = (CityListFragment) getFragmentManager().findFragmentById(R.id.cities);
if(list!=null) list.listByParentId(id);
getDialog().dismiss();
return true;
}
完整的代码：
package cn.com.demo.android.activity;
import cn.com.demo.R;
import cn.com.demo.android.activity.ProvinceList.ProvinceExpandableListAdapter;
import cn.com.demo.android.contentprovider.area.AreaContentProvider;
import cn.com.demo.android.db.AreaSQLiteHelper;
import cn.com.demo.android.service.AreaDBImpl;
import cn.com.demo.utility.MyActivity;
import android.app.DialogFragment;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.SimpleCursorTreeAdapter;
import android.widget.Spinner;
public class ProvinceListDialogFragment extends DialogFragment
implements MyActivity, ExpandableListView.OnChildClickListener{
private static final String TAG = ProvinceListDialogFragment.class.getSimpleName();
ExpandableListView lv;
private Cursor mGroupsCursor; // cursor for list of groups (list top nodes)
private int mGroupIdColumnIndex;
private ExpandableListAdapter mAdapter;
private AreaDBImpl s = new AreaDBImpl();
static ProvinceListDialogFragment newInstance() {
return new ProvinceListDialogFragment();
}
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Pick a style based on the num.
int style = DialogFragment.STYLE_NORMAL, theme = android.R.style.Theme_Holo_Light;
setStyle(style, theme);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.expandable_list, container, false);
lv = (ExpandableListView) v.findViewById(R.id.expandableList1);
Log.i(TAG, "lv is null:" + (lv==null?true:false));
mGroupsCursor = s.getListCursorByLevel(getActivity().getContentResolver(), 0);
getActivity().startManagingCursor(mGroupsCursor);
mGroupIdColumnIndex = mGroupsCursor.getColumnIndexOrThrow(AreaSQLiteHelper.COLUMN_ID);
// Set up our adapter
String s = getResources().getString(R.string.list_data_null);
mAdapter = new ProvinceExpandableListAdapter(
mGroupsCursor,
getActivity(),
android.R.layout.simple_expandable_list_item_1,
android.R.layout.simple_expandable_list_item_1,
new String[] {AreaSQLiteHelper.COLUMN_NAMES}, // group title for group layouts
new int[] { android.R.id.text1 },
new String[] {AreaSQLiteHelper.COLUMN_NAMES}, // exercise title for child layouts
new int[] { android.R.id.text1}
);
lv.setAdapter(mAdapter);
lv.setOnChildClickListener(this);
return v;
}
// extending SimpleCursorTreeAdapter
class ProvinceExpandableListAdapter extends SimpleCursorTreeAdapter {
public ProvinceExpandableListAdapter(Cursor cursor, Context context,
int groupLayout, int childLayout, String[] groupFrom,
int[] groupTo, String[] childrenFrom, int[] childrenTo) {
super(context, cursor, groupLayout, groupFrom, groupTo,
childLayout, childrenFrom, childrenTo);
}
// returns cursor with subitems for given group cursor
@Override
protected Cursor getChildrenCursor(Cursor groupCursor) {
int _countryId = groupCursor.getInt(groupCursor.getColumnIndexOrThrow(AreaSQLiteHelper.COLUMN_ID));
Cursor provinceCursor = s.getListCursorByParentId(getActivity().getContentResolver(), _countryId);
getActivity().startManagingCursor(provinceCursor);
return provinceCursor;
}
@Override
public boolean isChildSelectable(int groupPosition,
int childPosition) {
return true;
}
}
@Override
public boolean onChildClick(ExpandableListView parent, View v,
int groupPosition, int childPosition, long id) {
Log.i(TAG,"groupPosition=" + groupPosition + ", childPosition=" + childPosition + ", id=" + id);
CityListFragment list = (CityListFragment) getFragmentManager().findFragmentById(R.id.cities);
if(list!=null) list.listByParentId(id);
getDialog().dismiss();
return true;
}
}