显然我有问题！ 删除元素后，我需要刷新TabHost调用的内容（这是一个最喜欢的页面，我给了用户消除他想要的喜欢的可能性），我该怎么做？ 以下是“收藏夹”页面的代码（行在可扩展列表视图中）。
package it.sii.android.jobaroundu;
public class Preferiti extends ExpandableListActivity{
//Initialize variables
private static final String STR_CHECKED = " has Checked!";
private static final String STR_UNCHECKED = " has unChecked!";
private int ParentClickStatus=-1;
private int ChildClickStatus=-1;
//aggiustare creando la classe annunci_parent e annunci_child
private ArrayList<Parent> pref=new ArrayList<Parent>();
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
MyDBHelper dbHelper = new MyDBHelper(this,"JobAroundU_DB", null, 1);
SQLiteDatabase db=dbHelper.getWritableDatabase();
Resources res = this.getResources();
Drawable devider = res.getDrawable(R.drawable.line);
// Set ExpandableListView values
getExpandableListView().setGroupIndicator(null);
getExpandableListView().setDivider(devider);
getExpandableListView().setChildDivider(devider);
getExpandableListView().setDividerHeight(1);
registerForContextMenu(getExpandableListView());
//RECUPERO RICERCHE RECENTI
String sqlSavedPreferences="SELECT * FROM MyPreferences";
Cursor cursor = db.rawQuery(sqlSavedPreferences, null);
//creo padre e aggiungo ad esso le info
while (cursor.moveToNext()){
Parent p= new Parent();
p.setPosizione(cursor.getString(1));
p.setAzienza(cursor.getString(2));
p.setId(cursor.getString(4));
Log.i("Parent ID", p.getId());
Child cp = new Child();
cp.setDescrizione(cursor.getString(3));
p.setChildren(new ArrayList<Child>());
p.getChildren().add(cp);
pref.add(p);
}
db.close();
cursor.close();
//se parents e' vuoto --> messaggio errore --> non esistono preferiti salvati
if (pref.isEmpty()) {
LayoutInflater inflater = getLayoutInflater();
View layout = inflater.inflate(R.layout.toast_layout, (ViewGroup) findViewById(R.id.toast_layout_root));
ImageView image = (ImageView) layout.findViewById(R.id.immagine);
image.setImageDrawable(getResources().getDrawable(R.drawable.icon_25761));
TextView text = (TextView) layout.findViewById(R.id.ToastTV);
text.setText("Non ci sono preferiti da visualizzare!!!");
Toast toast = new Toast(getApplicationContext());
toast.setGravity(Gravity.CENTER_VERTICAL, 0, 0);
toast.setDuration(Toast.LENGTH_SHORT);
toast.setView(layout);
toast.show();
String n = getIntent().getStringExtra(getPackageName()+".Username");
Intent i = new Intent(this, PersonalPage.class);
i.putExtra(getPackageName()+".Username", n);
startActivity(i);
}
if (this.getExpandableListAdapter() == null) {
//Create ExpandableListAdapter Object
final MyExpandableListAdapter mAdapter = new MyExpandableListAdapter();
// Set Adapter to ExpandableList Adapter
this.setListAdapter(mAdapter);
}
else
{
// Refresh ExpandableListView data
((MyExpandableListAdapter)getExpandableListAdapter()).notifyDataSetChanged();
}
}
private class MyExpandableListAdapter extends BaseExpandableListAdapter{
private LayoutInflater inflater;
//protected SQLiteOpenHelper dbHelper2 =new MyDBHelper(PaginaRisultati.this,"JobAroundU_DB", null, 1);
public MyExpandableListAdapter(){
// Create Layout Inflator
inflater = LayoutInflater.from(Preferiti.this);
}
// This Function used to inflate parent rows view
@Override
public View getGroupView(final int groupPosition, boolean isExpanded, View convertView, ViewGroup parentView){
final Parent parent = pref.get(groupPosition);
// Inflate grouprow.xml file for parent rows
convertView = inflater.inflate(R.layout.grouprow_pref, parentView, false);
// Get grouprow.xml file elements and set values
((TextView) convertView.findViewById(R.id.text1)).setText(parent.getPosizione());
((TextView) convertView.findViewById(R.id.TVAzienda)).setText(parent.getAzienda());
ImageView image=(ImageView)convertView.findViewById(R.id.image_tag);
image.setImageResource(R.drawable.yellow_star);
ImageButton bin = (ImageButton)convertView.findViewById(R.id.imageButton_bin);
bin.setFocusable(false);
bin.setOnClickListener(new OnClickListener(){
@Override
public void onClick(final View v) {
AlertDialog.Builder alt_bld = new AlertDialog.Builder(Preferiti.this);
alt_bld.setMessage("Sei sicuro di voler eliminare l'utente dai preferiti?")
.setCancelable(false)
.setPositiveButton("Si", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id)
{
MyDBHelper dbHelper2 = new MyDBHelper(Preferiti.this,"JobAroundU_DB", null, 1);
SQLiteDatabase db2=dbHelper2.getWritableDatabase();
String sqlDelete = "DELETE FROM MyPreferences WHERE idDBJobs="+parent.getId()+";";
db2.execSQL(sqlDelete);
db2.close();
}
})
.setNegativeButton("No", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// Action for 'NO' Button
dialog.cancel();
}
});
AlertDialog alert = alt_bld.create();
// Title for AlertDialog
alert.setTitle("CANCELLARE QUESTO PREFERITO?");
// Icon for AlertDialog
alert.setIcon(R.drawable.trash_empty);
alert.show();
//elimino il preferito dal db
Log.i("DELETING", "I'm deleting "+parent.getId()+" Position: "+parent.getPosizione());
}
});
return convertView;
}
// This Function used to inflate child rows view
@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parentView){
final Parent parent = pref.get(groupPosition);
final Child child = parent.getChildren().get(childPosition);
// Inflate childrow.xml file for child rows
convertView = inflater.inflate(R.layout.childrow_pref, parentView, false);
// Get childrow.xml file elements and set values
/***DESCRIZIONE***/
((TextView) convertView.findViewById(R.id.TVDescrizione)).setText(child.getDescrizione());
ImageView image=(ImageView)convertView.findViewById(R.id.image_tag);
image.setImageResource(R.drawable.icon_16301);
return convertView;
}
@Override
public Object getChild(int groupPosition, int childPosition)
{
//Log.i("Childs", groupPosition+"= getChild =="+childPosition);
return pref.get(groupPosition).getChildren().get(childPosition);
}
//Call when child row clicked
@Override
public long getChildId(int groupPosition, int childPosition)
{
/****** When Child row clicked then this function call *******/
if( ChildClickStatus!=childPosition)
{
ChildClickStatus = childPosition;
}
return childPosition;
}
@Override
public int getChildrenCount(int groupPosition)
{
int size=0;
if(pref.get(groupPosition).getChildren()!=null)
size = pref.get(groupPosition).getChildren().size();
return size;
}
@Override
public Object getGroup(int groupPosition)
{
Log.i("Parent", groupPosition+"= getGroup ");
return pref.get(groupPosition);
}
@Override
public int getGroupCount()
{
return pref.size();
}
//Call when parent row clicked
@Override
public long getGroupId(int groupPosition)
{
ParentClickStatus=groupPosition;
if(ParentClickStatus==0)
ParentClickStatus=-1;
return groupPosition;
}
@Override
public void notifyDataSetChanged()
{
// Refresh List rows
super.notifyDataSetChanged();
}
@Override
public boolean isEmpty()
{
return ((pref == null) || pref.isEmpty());
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition)
{
return true;
}
/******************* Checkbox Checked Change Listener ********************/
private final class CheckUpdateListener implements OnCheckedChangeListener
{
private final Parent parent;
private CheckUpdateListener(Parent parent)
{
this.parent = parent;
}
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked)
{
Log.i("onCheckedChanged", "isChecked: "+isChecked);
parent.setChecked(isChecked);
((MyExpandableListAdapter)getExpandableListAdapter()).notifyDataSetChanged();
final Boolean checked = parent.isChecked();
}
}
/***********************************************************************/
@Override
public boolean hasStableIds() {
// TODO Auto-generated method stub
return false;
}
}
}
这里是TabHost的代码。
package it.sii.android.jobaroundu;
public class Preferiti extends ExpandableListActivity{
//Initialize variables
private static final String STR_CHECKED = " has Checked!";
private static final String STR_UNCHECKED = " has unChecked!";
private int ParentClickStatus=-1;
private int ChildClickStatus=-1;
//aggiustare creando la classe annunci_parent e annunci_child
private ArrayList<Parent> pref=new ArrayList<Parent>();
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
MyDBHelper dbHelper = new MyDBHelper(this,"JobAroundU_DB", null, 1);
SQLiteDatabase db=dbHelper.getWritableDatabase();
Resources res = this.getResources();
Drawable devider = res.getDrawable(R.drawable.line);
// Set ExpandableListView values
getExpandableListView().setGroupIndicator(null);
getExpandableListView().setDivider(devider);
getExpandableListView().setChildDivider(devider);
getExpandableListView().setDividerHeight(1);
registerForContextMenu(getExpandableListView());
//RECUPERO RICERCHE RECENTI
String sqlSavedPreferences="SELECT * FROM MyPreferences";
Cursor cursor = db.rawQuery(sqlSavedPreferences, null);
//creo padre e aggiungo ad esso le info
while (cursor.moveToNext()){
Parent p= new Parent();
p.setPosizione(cursor.getString(1));
p.setAzienza(cursor.getString(2));
p.setId(cursor.getString(4));
Log.i("Parent ID", p.getId());
Child cp = new Child();
cp.setDescrizione(cursor.getString(3));
p.setChildren(new ArrayList<Child>());
p.getChildren().add(cp);
pref.add(p);
}
db.close();
cursor.close();
//se parents e' vuoto --> messaggio errore --> non esistono preferiti salvati
if (pref.isEmpty()) {
LayoutInflater inflater = getLayoutInflater();
View layout = inflater.inflate(R.layout.toast_layout, (ViewGroup) findViewById(R.id.toast_layout_root));
ImageView image = (ImageView) layout.findViewById(R.id.immagine);
image.setImageDrawable(getResources().getDrawable(R.drawable.icon_25761));
TextView text = (TextView) layout.findViewById(R.id.ToastTV);
text.setText("Non ci sono preferiti da visualizzare!!!");
Toast toast = new Toast(getApplicationContext());
toast.setGravity(Gravity.CENTER_VERTICAL, 0, 0);
toast.setDuration(Toast.LENGTH_SHORT);
toast.setView(layout);
toast.show();
String n = getIntent().getStringExtra(getPackageName()+".Username");
Intent i = new Intent(this, PersonalPage.class);
i.putExtra(getPackageName()+".Username", n);
startActivity(i);
}
if (this.getExpandableListAdapter() == null) {
//Create ExpandableListAdapter Object
final MyExpandableListAdapter mAdapter = new MyExpandableListAdapter();
// Set Adapter to ExpandableList Adapter
this.setListAdapter(mAdapter);
}
else
{
// Refresh ExpandableListView data
((MyExpandableListAdapter)getExpandableListAdapter()).notifyDataSetChanged();
}
}
private class MyExpandableListAdapter extends BaseExpandableListAdapter{
private LayoutInflater inflater;
//protected SQLiteOpenHelper dbHelper2 =new MyDBHelper(PaginaRisultati.this,"JobAroundU_DB", null, 1);
public MyExpandableListAdapter(){
// Create Layout Inflator
inflater = LayoutInflater.from(Preferiti.this);
}
// This Function used to inflate parent rows view
@Override
public View getGroupView(final int groupPosition, boolean isExpanded, View convertView, ViewGroup parentView){
final Parent parent = pref.get(groupPosition);
// Inflate grouprow.xml file for parent rows
convertView = inflater.inflate(R.layout.grouprow_pref, parentView, false);
// Get grouprow.xml file elements and set values
((TextView) convertView.findViewById(R.id.text1)).setText(parent.getPosizione());
((TextView) convertView.findViewById(R.id.TVAzienda)).setText(parent.getAzienda());
ImageView image=(ImageView)convertView.findViewById(R.id.image_tag);
image.setImageResource(R.drawable.yellow_star);
ImageButton bin = (ImageButton)convertView.findViewById(R.id.imageButton_bin);
bin.setFocusable(false);
bin.setOnClickListener(new OnClickListener(){
@Override
public void onClick(final View v) {
AlertDialog.Builder alt_bld = new AlertDialog.Builder(Preferiti.this);
alt_bld.setMessage("Sei sicuro di voler eliminare l'utente dai preferiti?")
.setCancelable(false)
.setPositiveButton("Si", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id)
{
MyDBHelper dbHelper2 = new MyDBHelper(Preferiti.this,"JobAroundU_DB", null, 1);
SQLiteDatabase db2=dbHelper2.getWritableDatabase();
String sqlDelete = "DELETE FROM MyPreferences WHERE idDBJobs="+parent.getId()+";";
db2.execSQL(sqlDelete);
db2.close();
}
})
.setNegativeButton("No", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// Action for 'NO' Button
dialog.cancel();
}
});
AlertDialog alert = alt_bld.create();
// Title for AlertDialog
alert.setTitle("CANCELLARE QUESTO PREFERITO?");
// Icon for AlertDialog
alert.setIcon(R.drawable.trash_empty);
alert.show();
//elimino il preferito dal db
Log.i("DELETING", "I'm deleting "+parent.getId()+" Position: "+parent.getPosizione());
}
});
return convertView;
}
// This Function used to inflate child rows view
@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parentView){
final Parent parent = pref.get(groupPosition);
final Child child = parent.getChildren().get(childPosition);
// Inflate childrow.xml file for child rows
convertView = inflater.inflate(R.layout.childrow_pref, parentView, false);
// Get childrow.xml file elements and set values
/***DESCRIZIONE***/
((TextView) convertView.findViewById(R.id.TVDescrizione)).setText(child.getDescrizione());
ImageView image=(ImageView)convertView.findViewById(R.id.image_tag);
image.setImageResource(R.drawable.icon_16301);
return convertView;
}
@Override
public Object getChild(int groupPosition, int childPosition)
{
//Log.i("Childs", groupPosition+"= getChild =="+childPosition);
return pref.get(groupPosition).getChildren().get(childPosition);
}
//Call when child row clicked
@Override
public long getChildId(int groupPosition, int childPosition)
{
/****** When Child row clicked then this function call *******/
if( ChildClickStatus!=childPosition)
{
ChildClickStatus = childPosition;
}
return childPosition;
}
@Override
public int getChildrenCount(int groupPosition)
{
int size=0;
if(pref.get(groupPosition).getChildren()!=null)
size = pref.get(groupPosition).getChildren().size();
return size;
}
@Override
public Object getGroup(int groupPosition)
{
Log.i("Parent", groupPosition+"= getGroup ");
return pref.get(groupPosition);
}
@Override
public int getGroupCount()
{
return pref.size();
}
//Call when parent row clicked
@Override
public long getGroupId(int groupPosition)
{
ParentClickStatus=groupPosition;
if(ParentClickStatus==0)
ParentClickStatus=-1;
return groupPosition;
}
@Override
public void notifyDataSetChanged()
{
// Refresh List rows
super.notifyDataSetChanged();
}
@Override
public boolean isEmpty()
{
return ((pref == null) || pref.isEmpty());
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition)
{
return true;
}
/******************* Checkbox Checked Change Listener ********************/
private final class CheckUpdateListener implements OnCheckedChangeListener
{
private final Parent parent;
private CheckUpdateListener(Parent parent)
{
this.parent = parent;
}
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked)
{
Log.i("onCheckedChanged", "isChecked: "+isChecked);
parent.setChecked(isChecked);
((MyExpandableListAdapter)getExpandableListAdapter()).notifyDataSetChanged();
final Boolean checked = parent.isChecked();
}
}
/***********************************************************************/
@Override
public boolean hasStableIds() {
// TODO Auto-generated method stub
return false;
}
}
}
答案 0 :(得分：0)
试试这个：
pref.clear();
MyDBHelper dbHelper = new MyDBHelper(this,"JobAroundU_DB", null, 1);
SQLiteDatabase db=dbHelper.getWritableDatabase();
String sqlSavedPreferences="SELECT * FROM MyPreferences";
Cursor cursor = db.rawQuery(sqlSavedPreferences, null);
while (cursor.moveToNext()){
Parent p= new Parent();
p.setPosizione(cursor.getString(1));
p.setAzienza(cursor.getString(2));
p.setId(cursor.getString(4));
Log.i("Parent ID", p.getId());
Child cp = new Child();
cp.setDescrizione(cursor.getString(3));
p.setChildren(new ArrayList<Child>());
p.getChildren().add(cp);
pref.add(p);
}
db.close();
cursor.close();
// Refresh ExpandableListView data
((MyExpandableListAdapter)getExpandableListAdapter()).notifyDataSetChanged();
将上述代码添加到您的删除方法中，它应该可以正常工作。