我有一个ArrayList，它是我正在处理的培训日志的一部分。我已经设置好了，当我点击ListView的一个单元格（在 TrainingLog.java 中）时，它应该从数据库中删除该行，从而删除该单元格时的行表重新加载，但没有任何效果。我做错了什么（这是我的数据库 DBAdapter.java 的问题吗？），有没有更好的方法来解决这个问题？
TrainingLog.java ：
public class TrainingLog extends Fragment {
ListView lv;
ArrayList<String> players = new ArrayList<String>();
ArrayAdapter<String> adapter;
ArrayAdapter<String> clearAdapter;
ArrayList<String> details = new ArrayList<String>();
ArrayList<String> dates = new ArrayList<String>();
public TrainingLog() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View rootView = inflater.inflate(R.layout.fragment_training_log, container, false);
lv = (ListView) rootView.findViewById(R.id.myListView);
final DBAdapter db = new DBAdapter(this.getActivity());
setHasOptionsMenu(true);
players.clear();
details.clear();
dates.clear();
//OPEN
db.openDB();
//RETRIEVE
Cursor c=db.getAllNames();
while(c.moveToNext())
{
String name=c.getString(1);
players.add(name);
String pos=c.getString(2);
details.add(pos);
String date=c.getString(3);
dates.add(date);
}
db.close();
String[] playerArray = new String[players.size()];
playerArray = players.toArray(playerArray);
String[] detailArray = new String[details.size()];
detailArray = details.toArray(detailArray);
String[] datesArray = new String[dates.size()];
datesArray = dates.toArray(datesArray);
ListAdapter myAdapter = new TrainingAdapter(this.getActivity(), playerArray, detailArray, datesArray);
lv.setAdapter(myAdapter);
final String[] finalPlayerArray = playerArray;
final String[] finalDetailArray = detailArray;
final String[] finalDateArray = datesArray;
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
String player = finalPlayerArray[position];
String detail = finalDetailArray[position];
String onedate = finalDateArray[position];
//Toast.makeText(getActivity(),player, Toast.LENGTH_LONG).show();
//OPEN
db.openDB();
//Remove
db.deleteInterestID(position);
Toast.makeText(getActivity(), position, Toast.LENGTH_SHORT).show();
//CLOSE DB
db.close();
//Reload
players.clear();
details.clear();
dates.clear();
//OPEN
db.openDB();
//RETRIEVE
Cursor c=db.getAllNames();
while(c.moveToNext())
{
String name=c.getString(1);
players.add(name);
String pos=c.getString(2);
details.add(pos);
String date=c.getString(3);
dates.add(date);
}
db.close();
String[] playerArray = new String[players.size()];
playerArray = players.toArray(playerArray);
String[] detailArray = new String[details.size()];
detailArray = details.toArray(detailArray);
String[] datesArray = new String[dates.size()];
datesArray = dates.toArray(datesArray);
ListAdapter myAdapter = new TrainingAdapter(getActivity(), playerArray, detailArray, datesArray);
lv.setAdapter(myAdapter);
}
});
return rootView;
}
@Override
public void onResume() {
super.onResume();
final DBAdapter db = new DBAdapter(this.getActivity());
players.clear();
details.clear();
dates.clear();
///OPEN
db.openDB();
//RETRIEVE
Cursor c=db.getAllNames();
while(c.moveToNext())
{
String name=c.getString(1);
players.add(name);
String pos=c.getString(2);
details.add(pos);
String date=c.getString(3);
dates.add(date);
}
db.close();
String[] playerArray = new String[players.size()];
playerArray = players.toArray(playerArray);
String[] detailArray = new String[details.size()];
detailArray = details.toArray(detailArray);
String[] datesArray = new String[dates.size()];
datesArray = dates.toArray(datesArray);
ListAdapter myAdapter = new TrainingAdapter(this.getActivity(), playerArray, detailArray, datesArray);
lv.setAdapter(myAdapter);
final String[] finalPlayerArray = playerArray;
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
String player = finalPlayerArray[position];
//Toast.makeText(getActivity(),player, Toast.LENGTH_LONG).show();
}
});
}
@Override
public void onCreateOptionsMenu(
Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.traning_menu_itemdetail, menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// handle item selection
switch (item.getItemId()) {
case R.id.action_add:
Intent trainingCreateIntent = new Intent (getContext(), TrainingLogCreate.class);
startActivity(trainingCreateIntent);
return true;
default:
return super.onOptionsItemSelected(item);
}
}
}
将对DBAdapter ：
public class DBAdapter {
//COLUMNS
static final String ROWID="id";
static final String NAME = "name";
static final String POSITION = "position";
static final String DATE = "date";
//DB PROPERTIES
static final String DBNAME="m_DB";
static final String TBNAME="m_TB";
static final int DBVERSION='1';
static final String CREATE_TB="CREATE TABLE m_TB(id INTEGER PRIMARY KEY AUTOINCREMENT,"
+ "name TEXT NOT NULL,position TEXT NOT NULL,date TEXT NOT NULL);";
final Context c;
SQLiteDatabase db;
DBHelper helper;
public DBAdapter(FragmentActivity ctx) {
// TODO Auto-generated constructor stub
this.c=ctx;
helper=new DBHelper(c);
}
// INNER HELPER DB CLASS
private static class DBHelper extends SQLiteOpenHelper
{
public DBHelper(Context context ) {
super(context, DBNAME, null, DBVERSION);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase db) {
try
{
db.execSQL(CREATE_TB);
} catch (SQLException e) {
e.printStackTrace();
}
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
Log.w("DBAdapetr","Upgrading DB");
db.execSQL("DROP TABLE IF EXISTS m_TB");
onCreate(db);
}
}
// OPEN THE DB
public DBAdapter openDB()
{
try
{
db=helper.getWritableDatabase();
}catch(SQLException e)
{
Toast.makeText(c, e.getMessage(), Toast.LENGTH_LONG).show();
}
return this;
}
//CLOSE THE DB
public void close()
{
helper.close();
}
//INSERT INTO TABLE
public long add(String name,String pos, String date)
{
try
{
ContentValues cv=new ContentValues();
cv.put(NAME, name);
cv.put(POSITION, pos);
cv.put(DATE, date);
return db.insert(TBNAME, ROWID, cv);
}catch(SQLException e)
{
e.printStackTrace();
}
return 0;
}
//REMOVE FROM TABLE
public void deleteInterestID(int id) {
/* SQLiteDatabase db=helper.getWritableDatabase();
String[] whereArgs = {name};
db.delete(TBNAME, NAME+"=?", whereArgs); */
SQLiteDatabase db=helper.getWritableDatabase();
db.delete(TBNAME, NAME + "=?", new String[]{String.valueOf(id)});
db.close();
}
//GET ALL VALUES
public Cursor getAllNames()
{
String[] columns={ROWID,NAME,POSITION,DATE};
return db.query(TBNAME, columns, null, null, null, null, null);
}
}
编辑：CRASH ERROR ：
02-27 12:57:00.985 20189-20189/com.hardingsoftware.hrcfitness E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.hardingsoftware.hrcfitness, PID: 20189
android.content.res.Resources$NotFoundException: String resource ID #0x6
at android.content.res.Resources.getText(Resources.java:299)
at android.widget.Toast.makeText(Toast.java:285)
at com.hardingsoftware.hrcfitness.TrainingLog$1.onItemClick(TrainingLog.java:104)
at android.widget.AdapterView.performItemClick(AdapterView.java:305)
at android.widget.AbsListView.performItemClick(AbsListView.java:1146)
at android.widget.AbsListView$PerformClick.run(AbsListView.java:3053)
at android.widget.AbsListView$3.run(AbsListView.java:3860)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
答案 0 :(得分：1)
将删除方法签名更改为public void deleteInterestID(string pos) {并查询
db.delete(TBNAME, POSITION + "=?", new String[]{pos});
然后
db.deleteInterestID(position);
到
db.deleteInterestID(finalDetailArray[position]);
<强>更新
完全删除方法onResume。您已在onCreateView中拥有该代码。无需写两次。您将再次在此处添加侦听器，这将删除正在执行删除操作的onCreateView中添加的侦听器。
答案 1 :(得分：1)
通过查看DBAdapter，您有一个包含列ID，名称，位置和日期的表。
在 TrainingLog 中，您传递了position，并希望在 DBAdapter 中删除值与position相同的列。你指的是哪一栏？ position或id？
如果要删除position列中的值，请将此行db.delete(TBNAME, NAME + "=?", new String[]{String.valueOf(id)});更改为db.delete(TBNAME, POSITION + "=?", new String[]{String.valueOf(id)});（如果为ID），然后将POSITION更改为ROWID。
答案 2 :(得分：-1)
数据库中的所有问题都使用了交易 - ＆gt; db.beginTransaction（） - ＆gt; db.setTransactionSuccessful（） - ＆gt; db.endTransaction（），因此可以进行最终提交。