当我尝试使用游标创建包含来自数据库的数据的ListView时，我遇到了一些问题。 但是当我运行活动时，错误报告会给出错误消息：
java.lang.IllegalStateException：无法从CursorWindow读取第0行col -1。在从中访问数据之前，请确保Cursor已正确初始化。
我不知道发生了什么，我在StackOverFlow上搜索答案我找到了一些答案，我必须分配Cursor的值，但它仍然没有解决我的错误。 拜托，有人可以帮助我轻松理解单词。 谢谢。
NB。我的CategorySetting.java代码（Activity包含ListView）
public class CategorySetting extends Activity {
private SQLiteDatabase db;
private CustomCursorAdapter customAdapter ;
private static Button BtnIAddCateg;
private static Button BtnICancelCateg;
private static final String TAG = CategorySetting.class.getSimpleName();
DatabaseHelper dBHelper = new DatabaseHelper (this);
private ListView list;
private ArrayList<String> arrCategId = new ArrayList<String>();
private ArrayList<String> arrCategName = new ArrayList<String>();
private ArrayList<String> arrCategNote = new ArrayList<String>();
private ArrayList<String> arrCategCurr = new ArrayList<String>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_category_setting);
onButtonClickButtonListener();
//ListView list = getListView();
//showListView();
displayData();
}
public void showListView(){
list = (ListView)findViewById(android.R.id.list);
list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
Log.d(TAG, "clicked on item: " + arg2);
String label = arg0.getItemAtPosition(arg2).toString();
Toast.makeText(CategorySetting.this, "You Selected " + label, Toast.LENGTH_LONG).show();
//click to update data
Intent i = new Intent(getApplicationContext(), AddCategory.class);
//i.putExtra("CategId", arrCategId.get(arg2));
i.putExtra("CategName", arrCategName.get(arg2));
i.putExtra("CategNote", arrCategNote.get(arg2));
i.putExtra("CategCurr", arrCategCurr.get(arg2));
i.putExtra("update", true);
startActivity(i);
}
});
new Handler().post(new Runnable() {
@Override
public void run() {
customAdapter = new CustomCursorAdapter(CategorySetting.this, dBHelper.getAllData());
list.setAdapter(customAdapter);
}
});
}
private void displayData() {
db = dBHelper.getReadableDatabase();
Cursor mCursor = db.rawQuery("SELECT * FROM " + dBHelper.TABLE_Categ_NAME, null);
arrCategId.clear();
arrCategName.clear();
arrCategNote.clear();
arrCategCurr.clear();
if (mCursor.moveToFirst()) {
do {
arrCategId.add(mCursor.getString(mCursor.getColumnIndex(dBHelper.COL1)));// error disini make sure cursor is bla bla
arrCategName.add(mCursor.getString(mCursor.getColumnIndex(dBHelper.COL2)));
arrCategNote.add(mCursor.getString(mCursor.getColumnIndex(dBHelper.COL3)));
arrCategCurr.add(mCursor.getString(mCursor.getColumnIndex(dBHelper.COL4)));
} while (mCursor.moveToNext());
}
DisplayAdapter disadpt = new DisplayAdapter(CategorySetting.this, arrCategId, arrCategName, arrCategId, arrCategCurr);
list.setAdapter(disadpt);
mCursor.close();
}
//ListView view = getListView();
//iew.addHeaderView(getLayoutInflater().inflate(R.layout.row, null));
//db = dBHelper.getWritableDatabase();
//this.muat_ulang();
/*public void reload(){
try {
DatabaseHelper dbHelper = new DatabaseHelper(this.getApplicationContext());
db = dbHelper.getWritableDatabase();
Cursor c = db.rawQuery("SELECT CategName FROM " + tableName, null);
if (c != null ) {
if (c.moveToFirst()) {
do {
String categName = c.getString(c.getColumnIndex("CategName"));
}while (c.moveToNext());
}
}
} catch (SQLiteException se ) {
Log.e(getClass().getSimpleName(), "Could not create or Open the database");
} finally {
if (db != null)
db.execSQL("DELETE FROM " + tableName);
db.close();
}
}*/
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_category_setting, menu);
return true;
}
public void onButtonClickButtonListener(){
BtnIAddCateg = (Button)findViewById(R.id.btnAddNewCateg);
BtnIAddCateg.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intentAddCateg = new Intent ("com.example.ever_ncn.cashflow.AddCategory");
startActivity(intentAddCateg);
}
}
);
BtnICancelCateg = (Button)findViewById(R.id.btnCancelCateg);
BtnICancelCateg.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(
CategorySetting.this,
MainActivity.class
);
startActivity(intent);
}
}
);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
此DatabaseHelper.java
public class DatabaseHelper extends SQLiteOpenHelper {
public static final String MyVillageSoftware = "MyVillageSoftware";
public static final String DATABASE_NAME = "Cashflow.db";
public static final String TABLE_Categ_NAME = "category_table";
public static final String TABLE_Trans_NAME = "transaction_table";
public static final String COL1 = "CategId";
public static final String COL2 = "CategName";
public static final String COL3 = "Note";
public static final String COL4 = "Currency";
public static final String COL5 = "_id";
//TOL for transaction Coloumn
public static final String TOL1 = "TransId";
public static final String TOL2 = "TransName";
public static final String TOL3 = "Amount";
public static final String TOL4 = "TransNote";
public static final String TOL5 = "TransDate";
public static final String TOL6 = "CategId";
public static final String TOL7 = "_id";
private static final String TAG = DatabaseHelper.class.getSimpleName();
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, 9);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("Create table " + TABLE_Categ_NAME +
" (CategID Integer PRIMARY KEY AUTOINCREMENT, " +
"CategName Text," +
" Note Text," +
" Currency Text," +
" _id Text)");
db.execSQL("Create table " + TABLE_Trans_NAME +
" (TransID Integer PRIMARY KEY AUTOINCREMENT, " +
"TransName Text," +
" Amount Integer," +
" TransNote Text," +
" TransDate long," +
" CategId Text, " +
" _id Text)");
}
public boolean insertCategData(String categname, String note, String currency, String id){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(COL2, categname);
contentValues.put(COL3, note);
contentValues.put(COL4, currency);
contentValues.put(COL5, id);
long result = db.insert(TABLE_Categ_NAME, null, contentValues);
if (result == -1)
return false;
else
return true;
}
public boolean insertTransData (String transname, Integer amount, String transnote, long transdate, String categ, String id){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
//contentValues.put(TOL1, transname);
contentValues.put(TOL2, transname);
contentValues.put(TOL3, amount);
contentValues.put(TOL4, transnote);
contentValues.put(TOL5, transdate);
contentValues.put(TOL6, categ);
contentValues.put(TOL7, id);
long result = db.insert(TABLE_Trans_NAME, null, contentValues);
if (result == -1)
return false;
else
return true;
}
public List<String> getAllCategory() {
List<String> AllCategoryList = new ArrayList<String>();
String selectQuery = "SELECT * FROM " + TABLE_Categ_NAME;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
/*db = SQLiteDatabase.openDatabase(DATABASE_NAME, Context.MODE_PRIVATE, null);
Cursor allrows = db.rawQuery("SELECT * FROM " + TABLE_Categ_NAME, null);
System.out.println("COUNT : " + allrows.getCount());*/
if (cursor.moveToFirst()) {
do {
String ID = cursor.getString(0);
String Categ = cursor.getString(1);
String Note = cursor.getString(2);
String Curr = cursor.getString(3);
AllCategoryList.add(Categ);
} while (cursor.moveToNext());
}
cursor.close();
db.close();
return AllCategoryList;
}
public Cursor getAllData() {
SQLiteDatabase db = this.getReadableDatabase();
String buildSQL = "SELECT * FROM " + TABLE_Categ_NAME;
Log.d(TAG, "getAllData SQL: " + buildSQL);
return db.rawQuery(buildSQL, null);
}
/*public ArrayList<String>getAllCategory(){
ArrayList<String> AllCategoryList = new ArrayList<String>();
SQLiteDatabase db = this.getReadableDatabase();
String selectCateg="Select * FROM " +TABLE_Categ_NAME;
Cursor cursor = db.rawQuery(selectCateg, null);
if(cursor.getCount()>0){
while (cursor.moveToNext()){
String categname1=cursor.getString(cursor.getColumnIndex(COL2));
AllCategoryList.add(COL2);
}return AllCategoryList;
}
return AllCategoryList;
}*/
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_Categ_NAME);
db.execSQL("DROP TABLE IF EXISTS " + TABLE_Trans_NAME);
onCreate(db);
}
}
这个DisplayAdapter.java
public class DisplayAdapter extends BaseAdapter {
private Context mContext;
private ArrayList<String> categArrId;
private ArrayList<String> categArrName;
private ArrayList<String> categArrNote;
private ArrayList<String> categArrCurr;
public DisplayAdapter(Context c, ArrayList<String> categId,ArrayList<String> categName, ArrayList<String> categNote, ArrayList<String> categCurr) {
this.mContext = c;
this.categArrId = categId;
this.categArrName = categName;
this.categArrNote = categNote;
this.categArrCurr = categCurr;
}
public int getCount() {
// TODO Auto-generated method stub
return categArrId.size();
}
public Object getItem(int position) {
// TODO Auto-generated method stub
return null;
}
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}
public View getView(int pos, View child, ViewGroup parent) {
Holder mHolder;
LayoutInflater layoutInflater;
if (child == null) {
layoutInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
child = layoutInflater.inflate(R.layout.categsetlist, null);
mHolder = new Holder();
mHolder.txt_id = (TextView) child.findViewById(R.id.txt_id);
mHolder.txt_name = (TextView) child.findViewById(R.id.txt_categnamelist);
mHolder.txt_note = (TextView) child.findViewById(R.id.txt_categnotelist);
mHolder.txt_curr = (TextView) child.findViewById(R.id.txt_categcurrlist);
child.setTag(mHolder);
} else {
mHolder = (Holder) child.getTag();
}
mHolder.txt_name.setText(categArrName.get(pos));
return child;
}
public class Holder {
TextView txt_id;
TextView txt_name;
TextView txt_note;
TextView txt_curr;
}
}
答案 0 :(得分：0)
好吧，看看你的代码，我发现：
DatabaseHelper.COL1 CategId onCreate CategID mCursor.getColumnIndex(dBHelper.COL1)作为列名称时，documentClient.createDocument(
getTodoCollection().getSelfLink(), document, null,
false)
为- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
// if (cell == nil){
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
// }
if (indexPath.row==0)
{
UILabel *lbl_label = [[UILabel alloc] initWithFrame:CGRectMake(15, 7, 200, 25)];
lbl_label.text = @"PRICE";
[lbl_label setFont:NORMAL_LABEL(16)];
[lbl_label setTextColor:UIColorFromRGB(0x565A5C,1.0)];
UILabel *lbl_price = [[UILabel alloc] initWithFrame:CGRectMake(100, 7, 200, 25)];
lbl_price.text = @"$ 50";
[lbl_price setFont:NORMAL_LABEL(16)];
[lbl_price setTextColor:[UIColor grayColor]];
[lbl_price setTextColor:UIColorFromRGB(0x82898D,1.0)];
lbl_price.textAlignment = NSTextAlignmentRight;
[cell addSubview:lbl_price];
[cell addSubview:lbl_label];
}
else if (indexPath.row==1)
{
UILabel *lbl_label = [[UILabel alloc] initWithFrame:CGRectMake(15, 7, 200, 25)];
lbl_label.text = @"CUISINE";
[lbl_label setFont:NORMAL_LABEL(16)];
[lbl_label setTextColor:UIColorFromRGB(0x565A5C,1.0)];
UILabel *lbl_price = [[UILabel alloc] initWithFrame:CGRectMake(100, 7, 200, 25)];
lbl_price.text = @"Sushi, Japanese, Arabian";
[lbl_price setFont:NORMAL_LABEL(16)];
[lbl_price setTextColor:[UIColor grayColor]];
[lbl_price setTextColor:UIColorFromRGB(0x82898D,1.0)];
lbl_price.textAlignment = NSTextAlignmentRight;
[cell addSubview:lbl_price];
[cell addSubview:lbl_label];
}
else if (indexPath.row==2)
{
UILabel *lbl_label = [[UILabel alloc] initWithFrame:CGRectMake(15, 7, 200, 25)];
lbl_label.text = @"GOOD FOR";
[lbl_label setFont:NORMAL_LABEL(16)];
[lbl_label setTextColor:UIColorFromRGB(0x565A5C,1.0)];
UILabel *lbl_price = [[UILabel alloc] initWithFrame:CGRectMake(100,7, 200, 25)];
lbl_price.text = @"Alcohol, Brunch";
[lbl_price setFont:NORMAL_LABEL(16)];
[lbl_price setTextColor:[UIColor grayColor]];
[lbl_price setTextColor:UIColorFromRGB(0x82898D,1.0)];
lbl_price.textAlignment = NSTextAlignmentRight;
[cell addSubview:lbl_price];
[cell addSubview:lbl_label];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
return cell;
- ＆GT;因此找不到order by