我正在使用Expandable ListView,其中的数据通过Sqlite数据库填充.我已经选择从ExpandableListView中删除一个组,它实际上删除了数据库中的相应行.但是活动不会刷新,删除的“案例”是可见的,直到有人返回并重新参加此活动.

我创建了一个扩展* BaseExpandableListAdapter *的类.它包含所有重写的方法.以下是代码：

public class ExpandableListAdapterForRunning extends BaseExpandableListAdapter {

private Context _context;

private List _listDataHeader; // header titles

public static List _listDate;

public int index;

// child data in format of header title, child title

private HashMap> _listDataChild;

public ExpandableListAdapterForRunning(Context context, List listDataHeader,

HashMap> listChildData,int i,List listDate) {

this._context = context;

this._listDataHeader = listDataHeader;

this._listDataChild = listChildData;

this.index=i;

this._listDate=listDate;

}

@Override

public Object getChild(int groupPosition, int childPosititon) {

return this._listDataChild.get(this._listDataHeader.get(groupPosition))

.get(childPosititon);

}

//other overridden methods

}

现在有另一个类RunningCase.java扩展了Activity.此类用于填充ExpandableListView中的数据.在ExpandableListView中的任何组的OnLongClick()(点击并按住)中,将出现一个上下文菜单.上下文菜单包含一个选项Delete,用于从数据库中删除该案例并刷新RunningCase活动.

public class RunningCase extends Activity

{

String[] day;

LinearLayout layout_MainMenu;

Case cases;

ExpandableListAdapterForRunning listAdapter;

ExpandableListView expListView;

List listDataHeader;

List listDate;

HashMap> listDataChild;

Case date;

protected void onCreate(Bundle savedInstanceState) {

prepareListData();

expListView=(ExpandableListView) findViewById(R.id.lvExp);

listAdapter= new ExpandableListAdapterForRunning(this,listDataHeader,listDataChild,i,listDate);

expListView.setAdapter(listAdapter);

registerForContextMenu(expListView);

}

@Override

public void onCreateContextMenu(ContextMenu menu, View v,

ContextMenuInfo menuInfo) {

super.onCreateContextMenu(menu, v, menuInfo);

menu.add("Delete");

}

@Override

public boolean onContextItemSelected(MenuItem item) {

// TODO Auto-generated method stub

super.onContextItemSelected(item);

final DatabaseHandler dbs = new DatabaseHandler(this);

Cursor c = null;

ExpandableListView.ExpandableListContextMenuInfo info = (ExpandableListView.ExpandableListContextMenuInfo) item

.getMenuInfo();

int type = ExpandableListView.getPackedPositionType(info.packedPosition);

int groupPosition = ExpandableListView.getPackedPositionGroup(info.packedPosition);

if (type == ExpandableListView.PACKED_POSITION_TYPE_GROUP) {

String cp=(String) listAdapter.getChild(groupPosition, 0);

caseno=cp.substring(11, cp.length());

}

if(item.getTitle()=="Delete")

{

dbs.deletecase(caseno);

expListView.post(new Runnable() {

public void run() {

listAdapter.notifyDataSetChanged(); //this is not working

}

});

Toast.makeText(this, "The Case has been Deleted.", Toast.LENGTH_LONG).show();

}

return true;

}

//this is the method to populate the expandableListView

public void prepareListData() {

listDataHeader = new ArrayList();

listDate =new ArrayList();

listDataChild = new HashMap>();

final DatabaseHandler db = new DatabaseHandler(this);

List cases = db.getRunning();

int i=0;

for (Case cn : cases) {

String str = cn.getPetitioner()+" V/S " + cn.getDefendant();

String caseNo=cn.getCaseNumber();

String caseStage=cn.getCaseStage();

String caseName=cn.getCourtName();

listDataHeader.add(str);

List case2 = new ArrayList();

case2.add("Case No. : "+caseNo);

case2.add("Court Name :"+caseName);

case2.add("Case Stage :"+caseStage);

listDataChild.put(listDataHeader.get(i++), case2);

}

List date = db.getRunning_child();

for (Date cn : date) {

String str = cn.getNextDate();

listDate.add(str);

}

}

方法db.getRunning(),db.getRunning_child()从数据库中检索数据.

此外,以下是从数据库中删除案例的代码,它完美地工作：

void deletecase(String casenum){

SQLiteDatabase db = this.getWritableDatabase();

String whereClause = "Case_number = ?";

String[] whereArgs = new String[] {

casenum

};

db.delete(TABLE_CASEINFO,whereClause,whereArgs);

db.delete(TABLE_CLIENTINFO,whereClause,whereArgs);

db.delete(TABLE_DATEINFO,whereClause,whereArgs);

Log.d("case deleted","casenum: "+casenum);

db.close(); // Closing database connection

}

请帮帮我.删除案例时应刷新活动,以便不再显示已删除的案例.

提前致谢！！

解决方法:

在调用notfifyDataSetChanged之前,您应该更新您的私有HashMap>数据. _listDataChild是由您在适配器上创建的setData方法.首先设置数据,然后通知.

例：

public class MyAdapter extends BaseAdapter {

public MyAdapter(...) {

super(...);

}

@Override

public View getView(int position, View view, ViewGroup parent) {

.....

return view;

}

private void setData() {

...

notifyDataSetChanged();

}

}

标签：android,expandablelistview,notifydatasetchanged

来源： https://codeday.me/bug/20190703/1365444.html