Java 删除项目后Android Listview未更新
我正在使用sqllite。我已经成功地创建了一个数据库，我可以在数据库中输入一些值。我还可以在listview中显示所有值，也可以通过listview的onitemclicklistener删除项。我有一个问题。删除项目时，listview未更新，但该项目已在数据库中删除。如何解决此问题 java代码Java 删除项目后Android Listview未更新,java,android,android-listview,android-sqlite,baseadapter,Java,Android,Android Listview,Android Sqlite,Baseadapter,我正在使用sqllite。我已经成功地创建了一个数据库，我可以在数据库中输入一些值。我还可以在listview中显示所有值，也可以通过listview的onitemclicklistener删除项。我有一个问题。删除项目时，listview未更新，但该项目已在数据库中删除。如何解决此问题 java代码 public class DatabaseHandler extends SQLiteOpenHelper { private static final int DATABASE_VERSIO
public class DatabaseHandler extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "lvstone_2";
private static final String TABLE_CONTACTS = "CardTable1";
private static final String KEY_ID = "id";
private static final String KEY_Tittle = "name";
private static final String KEY_Description = "description";
private static final String KEY_Price = "price";
private static final String KEY_Counter = "counter";
private static final String KEY_Image = "image";
private final ArrayList<Contact> contact_list = new ArrayList<Contact>();
public static SQLiteDatabase db;
public DatabaseHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
// Creating Tables
@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_CONTACTS + "("
+ KEY_ID + " INTEGER PRIMARY KEY," + KEY_Tittle + " TEXT,"
+ KEY_Description + " TEXT,"
+ KEY_Price + " TEXT,"
+ KEY_Counter + " TEXT,"
+ KEY_Image + " TEXT"
+ ")";
db.execSQL(CREATE_CONTACTS_TABLE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_CONTACTS);
// Create tables again
onCreate(db);
}
// Adding new contact
public void Add_Contact(Contact contact) {
db = this.getWritableDatabase();
ContentValues values = new ContentValues();
if (!somethingExists(contact.getTitle())) {
values.put(KEY_Tittle, contact.getTitle()); // Contact title
values.put(KEY_Description, contact.getDescription()); // Contact//
// description
values.put(KEY_Price, contact.getPrice()); // Contact price
values.put(KEY_Counter, contact.getCounter()); // Contact image
values.put(KEY_Image, contact.getImage()); // Contact image
// Inserting Row
db.insert(TABLE_CONTACTS, null, values);
Log.e("Table Result isss", String.valueOf(values));
db.close(); // Closing database connection
}
}
public void deleteUser(String userName)
{
db = this.getWritableDatabase();
try
{
db.delete(TABLE_CONTACTS, "name = ?", new String[] { userName });
}
catch(Exception e)
{
e.printStackTrace();
}
finally
{
db.close();
}
}
// Getting single contact
Contact Get_Contact(int id) {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(TABLE_CONTACTS,
new String[] { KEY_ID, KEY_Tittle, KEY_Description, KEY_Price,
KEY_Counter, KEY_Image }, KEY_ID + "=?",
new String[] { String.valueOf(id) }, null, null, null);
if (cursor != null)
cursor.moveToFirst();
Contact contact = new Contact(cursor.getString(0), cursor.getString(1),
cursor.getString(2), cursor.getString(4), cursor.getString(5));
// return contact
cursor.close();
db.close();
return contact;
}
public boolean somethingExists(String x) {
Cursor cursor = db.rawQuery("select * from " + TABLE_CONTACTS
+ " where name like '%" + x + "%'", null);
boolean exists = (cursor.getCount() > 0);
Log.e("Databaseeeeeeeee", String.valueOf(cursor));
cursor.close();
return exists;
}
public ArrayList<Contact> Get_Contacts() {
try {
contact_list.clear();
// Select All Query
String selectQuery = "SELECT * FROM " + TABLE_CONTACTS;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
Contact contact = new Contact();
contact.setTitle(cursor.getString(1));
contact.setDescription(cursor.getString(2));
contact.setPrice(cursor.getString(3));
contact.setCounter(cursor.getString(4));
contact.setImage(cursor.getString(5));
contact_list.add(contact);
} while (cursor.moveToNext());
}
cursor.close();
db.close();
return contact_list;
} catch (Exception e) {
// TODO: handle exception
Log.e("all_contact", "" + e);
}
return contact_list;
}
public int getProfilesCount() {
String countQuery = "SELECT * FROM " + TABLE_CONTACTS;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
int cnt = cursor.getCount();
cursor.close();
return cnt;
}
public class StradaSQLAdapter extends BaseAdapter {
Activity activity;
int layoutResourceId;
Contact user;
ArrayList<Contact> data = new ArrayList<Contact>();
public ImageLoader imageLoader;
UserHolder holder = null;
public int itemSelected = 0;
public StradaSQLAdapter(Activity act, int layoutResourceId,
ArrayList<Contact> data) {
this.layoutResourceId = layoutResourceId;
this.activity = act;
this.data = data;
imageLoader = new ImageLoader(act.getApplicationContext());
notifyDataSetChanged();
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
View row = convertView;
if (row == null) {
LayoutInflater inflater = LayoutInflater.from(activity);
holder = new UserHolder();
row = inflater.inflate(layoutResourceId, parent, false);
holder.Title = (TextView) row.findViewById(R.id.smalltitle1);
holder.counter = (TextView) row.findViewById(R.id.smallCounter1);
holder.dbcounter = (TextView) row
.findViewById(R.id.DBSliderCounter);
holder.Description = (TextView) row.findViewById(R.id.smallDesc1);
holder.layout = (RelativeLayout) row
.findViewById(R.id.DBSlideLayout);
holder.layoutmain = (RelativeLayout) row
.findViewById(R.id.DBSlideLayoutMain);
holder.Price = (TextView) row.findViewById(R.id.smallPrice1);
holder.pt = (ImageView) row.findViewById(R.id.smallthumb1);
holder.close = (ImageView) row.findViewById(R.id.DBSliderClose);
holder.c_minus = (ImageView) row.findViewById(R.id.counter_minus);
holder.c_plus = (ImageView) row.findViewById(R.id.counter_plus);
row.setTag(holder);
} else {
holder = (UserHolder) row.getTag();
}
user = data.get(position);
holder.Title.setText(user.getTitle());
holder.Description.setText(user.getDescription());
holder.Price.setText(user.getPrice() + " GEL");
holder.counter.setText(user.getCounter());
holder.dbcounter.setText(user.getCounter());
Log.e("image Url is........", data.get(position).toString());
imageLoader.DisplayImage(user.getImage(), holder.pt);
return row;
}
@Override
public int getCount() {
return data.size();
}
@Override
public Object getItem(int position) {
return data.get(position);
}
@Override
public long getItemId(int position) {
return 0;
}
public class UserHolder {
public TextView Price, counter, Description, Title, dbcounter;
public ImageView pt,close,c_plus,c_minus;
public RelativeLayout layout, layoutmain;
}
公共类DatabaseHandler扩展了SQLiteOpenHelper{
私有静态最终int数据库_VERSION=1；
私有静态最终字符串数据库\u NAME=“lvstone\u 2”；
私有静态最终字符串表\u CONTACTS=“CardTable1”；
私有静态最终字符串密钥\u ID=“ID”；
私有静态最终字符串密钥\u title=“name”；
私有静态最终字符串键\u Description=“Description”；
私有静态最终字符串键\u Price=“Price”；
私有静态最终字符串键\u Counter=“Counter”；
私有静态最终字符串键\u Image=“Image”；
private final ArrayList contact_list=新建ArrayList（）；
公共静态数据库sqlitedb；
公共数据库处理程序（上下文）{
super（上下文、数据库名称、null、数据库版本）；
}
//创建表
@凌驾
public void onCreate（SQLiteDatabase db）{
字符串CREATE_CONTACTS_TABLE=“CREATE TABLE”+TABLE_CONTACTS+”（“
+键ID+“整数主键，”+键标题+“文本，”
+密钥描述+文本
+键+价格+文本
+按键计数器+“文本，”
+按键图像+“文本”
+ ")";
execSQL（创建联系人表）；
}
@凌驾
public void onUpgrade（SQLiteDatabase db，int-oldVersion，int-newVersion）{
db.execSQL（“如果存在删除表”+表_联系人）；
//再次创建表
onCreate（db）；
}
//添加新联系人
公共无效添加联系人（联系人联系人）{
db=this.getWritableDatabase（）；
ContentValues=新的ContentValues（）；
如果（！somethingExists（contact.getTitle（）））{
value.put（KEY_title，contact.getTitle（））；//联系人标题
value.put（KEY_Description，contact.getDescription（））；//contact//
//描述
value.put（KEY_Price，contact.getPrice（））；//contact Price
value.put（KEY_Counter，contact.getCounter（））；//联系人图像
value.put（KEY_Image，contact.getImage（））；//contact Image
//插入行
db.插入（表_触点，空，值）；
Log.e（“表结果isss”，String.valueOf（values））；
db.close（）；//关闭数据库连接
}
}
public void deleteUser（字符串用户名）
{
db=this.getWritableDatabase（）；
尝试
{
db.delete（表_CONTACTS，“name=？”，新字符串[]{userName}）；
}
捕获（例外e）
{
e、 printStackTrace（）；
}
最后
{
db.close（）；
}
}
//获得单一联系
联系人获取联系人（int id）{
SQLiteDatabase db=this.getReadableDatabase（）；
Cursor=db.query（表，
新字符串[]{KEY_ID，KEY_title，KEY_Description，KEY_Price，
按键计数器，按键图像}，按键ID+“=？”，
新字符串[]{String.valueOf（id）}，null，null，null）；
如果（光标！=null）
cursor.moveToFirst（）；
联系人=新联系人（cursor.getString（0）、cursor.getString（1），
cursor.getString（2）、cursor.getString（4）、cursor.getString（5））；
//回接
cursor.close（）；
db.close（）；
回接；
}
公共布尔somethingExists（字符串x）{
Cursor Cursor=db.rawQuery（“选择*自”+表\u联系人
+其中名称类似“%”+x+“%”，null）；
布尔存在=（cursor.getCount（）>0）；
Log.e（“databaseeee”，String.valueOf（cursor））；
cursor.close（）；
回报存在；
}
public ArrayList Get_Contacts（）{
试一试{
联系人列表。清除（）；
//选择所有查询
String selectQuery=“SELECT*FROM”+表格\联系人；
SQLiteDatabase db=this.getWritableDatabase（）；
Cursor Cursor=db.rawQuery（selectQuery，null）；
//循环遍历所有行并添加到列表
if（cursor.moveToFirst（））{
做{
触点=新触点（）；
contact.setTitle（cursor.getString（1））；
contact.setDescription（cursor.getString（2））；
contact.setPrice（cursor.getString（3））；
contact.setCounter（cursor.getString（4））；
contact.setImage（cursor.getString（5））；
联系人列表。添加（联系人）；
}while（cursor.moveToNext（））；
}
cursor.close（）；
db.close（）；
返回联系人列表；
}捕获（例外e）{
//TODO:处理异常
Log.e（“所有联系人”和“+e”）；
}
返回联系人列表；
}
public int getProfileScont（）{
String countQuery=“SELECT*FROM”+表\u联系人；
SQLiteDatabase db=this.getReadableDatabase（）；
Cursor Cursor=db.rawQuery（countQuery，null）；
int cnt=cursor.getCount（）；
cursor.close（）；
返回cnt；
}
public class DatabaseHandler extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "lvstone_2";
private static final String TABLE_CONTACTS = "CardTable1";
private static final String KEY_ID = "id";
private static final String KEY_Tittle = "name";
private static final String KEY_Description = "description";
private static final String KEY_Price = "price";
private static final String KEY_Counter = "counter";
private static final String KEY_Image = "image";
private final ArrayList<Contact> contact_list = new ArrayList<Contact>();
public static SQLiteDatabase db;
public DatabaseHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
// Creating Tables
@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_CONTACTS + "("
+ KEY_ID + " INTEGER PRIMARY KEY," + KEY_Tittle + " TEXT,"
+ KEY_Description + " TEXT,"
+ KEY_Price + " TEXT,"
+ KEY_Counter + " TEXT,"
+ KEY_Image + " TEXT"
+ ")";
db.execSQL(CREATE_CONTACTS_TABLE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_CONTACTS);
// Create tables again
onCreate(db);
}
// Adding new contact
public void Add_Contact(Contact contact) {
db = this.getWritableDatabase();
ContentValues values = new ContentValues();
if (!somethingExists(contact.getTitle())) {
values.put(KEY_Tittle, contact.getTitle()); // Contact title
values.put(KEY_Description, contact.getDescription()); // Contact//
// description
values.put(KEY_Price, contact.getPrice()); // Contact price
values.put(KEY_Counter, contact.getCounter()); // Contact image
values.put(KEY_Image, contact.getImage()); // Contact image
// Inserting Row
db.insert(TABLE_CONTACTS, null, values);
Log.e("Table Result isss", String.valueOf(values));
db.close(); // Closing database connection
}
}
public void deleteUser(String userName)
{
db = this.getWritableDatabase();
try
{
db.delete(TABLE_CONTACTS, "name = ?", new String[] { userName });
}
catch(Exception e)
{
e.printStackTrace();
}
finally
{
db.close();
}
}
// Getting single contact
Contact Get_Contact(int id) {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(TABLE_CONTACTS,
new String[] { KEY_ID, KEY_Tittle, KEY_Description, KEY_Price,
KEY_Counter, KEY_Image }, KEY_ID + "=?",
new String[] { String.valueOf(id) }, null, null, null);
if (cursor != null)
cursor.moveToFirst();
Contact contact = new Contact(cursor.getString(0), cursor.getString(1),
cursor.getString(2), cursor.getString(4), cursor.getString(5));
// return contact
cursor.close();
db.close();
return contact;
}
public boolean somethingExists(String x) {
Cursor cursor = db.rawQuery("select * from " + TABLE_CONTACTS
+ " where name like '%" + x + "%'", null);
boolean exists = (cursor.getCount() > 0);
Log.e("Databaseeeeeeeee", String.valueOf(cursor));
cursor.close();
return exists;
}
public ArrayList<Contact> Get_Contacts() {
try {
contact_list.clear();
// Select All Query
String selectQuery = "SELECT * FROM " + TABLE_CONTACTS;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
Contact contact = new Contact();
contact.setTitle(cursor.getString(1));
contact.setDescription(cursor.getString(2));
contact.setPrice(cursor.getString(3));
contact.setCounter(cursor.getString(4));
contact.setImage(cursor.getString(5));
contact_list.add(contact);
} while (cursor.moveToNext());
}
cursor.close();
db.close();
return contact_list;
} catch (Exception e) {
// TODO: handle exception
Log.e("all_contact", "" + e);
}
return contact_list;
}
public int getProfilesCount() {
String countQuery = "SELECT * FROM " + TABLE_CONTACTS;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
int cnt = cursor.getCount();
cursor.close();
return cnt;
}
public class StradaSQLAdapter extends BaseAdapter {
Activity activity;
int layoutResourceId;
Contact user;
ArrayList<Contact> data = new ArrayList<Contact>();
public ImageLoader imageLoader;
UserHolder holder = null;
public int itemSelected = 0;
public StradaSQLAdapter(Activity act, int layoutResourceId,
ArrayList<Contact> data) {
this.layoutResourceId = layoutResourceId;
this.activity = act;
this.data = data;
imageLoader = new ImageLoader(act.getApplicationContext());
notifyDataSetChanged();
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
View row = convertView;
if (row == null) {
LayoutInflater inflater = LayoutInflater.from(activity);
holder = new UserHolder();
row = inflater.inflate(layoutResourceId, parent, false);
holder.Title = (TextView) row.findViewById(R.id.smalltitle1);
holder.counter = (TextView) row.findViewById(R.id.smallCounter1);
holder.dbcounter = (TextView) row
.findViewById(R.id.DBSliderCounter);
holder.Description = (TextView) row.findViewById(R.id.smallDesc1);
holder.layout = (RelativeLayout) row
.findViewById(R.id.DBSlideLayout);
holder.layoutmain = (RelativeLayout) row
.findViewById(R.id.DBSlideLayoutMain);
holder.Price = (TextView) row.findViewById(R.id.smallPrice1);
holder.pt = (ImageView) row.findViewById(R.id.smallthumb1);
holder.close = (ImageView) row.findViewById(R.id.DBSliderClose);
holder.c_minus = (ImageView) row.findViewById(R.id.counter_minus);
holder.c_plus = (ImageView) row.findViewById(R.id.counter_plus);
row.setTag(holder);
} else {
holder = (UserHolder) row.getTag();
}
user = data.get(position);
holder.Title.setText(user.getTitle());
holder.Description.setText(user.getDescription());
holder.Price.setText(user.getPrice() + " GEL");
holder.counter.setText(user.getCounter());
holder.dbcounter.setText(user.getCounter());
Log.e("image Url is........", data.get(position).toString());
imageLoader.DisplayImage(user.getImage(), holder.pt);
return row;
}
@Override
public int getCount() {
return data.size();
}
@Override
public Object getItem(int position) {
return data.get(position);
}
@Override
public long getItemId(int position) {
return 0;
}
public class UserHolder {
public TextView Price, counter, Description, Title, dbcounter;
public ImageView pt,close,c_plus,c_minus;
public RelativeLayout layout, layoutmain;
}
公共类StraaSqlAdapter扩展了BaseAdapter{
活动；
国际布局资源；
联系用户；
ArrayList数据=新的ArrayList（）；
公共图像加载器；
UserHolder=null；
公共int itemSelected=0；
公共设施（活动法、内部布局资源、，
ArrayList数据）{
this.layoutResourceId=layoutResourceId；
这个活动=行动；
这个数据=数据；
imageLoader=新的imageLoader（act.getApplicationContext（））；
notifyDataSetChanged（）；
}
@凌驾
公共视图getView（最终整数位置、视图转换视图、视图组父视图）{
视图行=转换视图；
if（行==null）{
LayoutFlater充气机=LayoutFlater.from（活动）；
holder=新用户holder（）；
行=充气机。充气（layoutResourceId，父级，false）；
holder.Title=（TextView）row.f
public void removeObject (int position) {
this.data.remove(position);
}
contact_data.remove(position);
cAdapter.removeObject(position);
cAdapter.notifyDataSetChanged();
contact_data.clear();
data.clear();