好的，所以我想在listview中单击一行后向我的数据库中添加一个项目。我只能从我的customAdapter类中获取onclickListener并启动对话框，但在添加项目后，我在调用onCreate时从我的db getWritableData方法收到错误。
我觉得问题在于我向additem添加3个字符串而不是添加项目。虽然我不太确定如何将项数据传递给dbHandler.addItem方法或传递3个字符串，就像我正在做的那样
public class searchResults extends AppCompatActivity {
private String websiteString, searchString;
private int pos;
private List<item> li;
private ListView lv;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_search_results);
Bundle searchBundle = getIntent().getExtras();
if (searchBundle == null) {
return;
}
searchString = searchBundle.getString("searchString");
websiteString = searchBundle.getString("websiteString");
TextView searchText = (TextView) findViewById(R.id.searchResultsTextView);
searchText.setText("Search for: " + searchString + " from " + websiteString);
li = searchBundle.getParcelableArrayList("itemL");
int count = li.size();
String[] imgLi = new String[count], descLi = new String[count], priceLi = new String[count];
int i = 0;
for(item l : li){
String img = l.getImage(), desc = l.getItemName(), price = l.getPrice();
imgLi[i] = img;
descLi[i] = desc;
priceLi[i] = price;
i++;
}
final int selectedListItem = getIntent().getIntExtra("PositionInList", -1);
lv=(ListView) findViewById(R.id.searchResultsListView);
lv.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
lv.setSelection(selectedListItem);
lv.setAdapter(new CustomAdapter(this, imgLi, descLi, priceLi));
}
}
CustomAdapter.java
public class CustomAdapter extends BaseAdapter {
private String [] image, desc, price;
private Context context;
private ListView lv;
private static LayoutInflater inflater=null;
public CustomAdapter(Activity mainActivity, String[] imageList, String[] descList, String[] priceList) {
// TODO Auto-generated constructor stub
image = imageList;
desc = descList;
price = priceList;
context=mainActivity;
inflater = ( LayoutInflater )context.
getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return image.length;
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
public class Holder
{
TextView tv;
TextView tv1;
ImageView img;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
final DBHandler dbHandler = new DBHandler(context, null, null, 1);
Holder holder=new Holder();
final View rowView;
rowView = inflater.inflate(R.layout.item_list, null);
holder.tv=(TextView) rowView.findViewById(R.id.textViewDesc);
holder.tv1=(TextView) rowView.findViewById(R.id.textViewPrice);
holder.img=(ImageView) rowView.findViewById(R.id.imageViewImage);
holder.tv.setText(desc[position]);
holder.tv1.setText(price[position]);
String url = image[position];
lv = (ListView) rowView.findViewById(R.id.searchResultsListView);
try {
new ImageDownloaderTask(holder.img).execute(url);
} catch (Exception e) {
e.printStackTrace();
}
rowView.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(context);
alertDialogBuilder.setMessage("Are you sure you want to add item to PriceWatcher");
alertDialogBuilder.setPositiveButton("Yes",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface arg0, int arg1) {
//do what you want to do if user clicks ok
dbHandler.addItem(image[position], desc[position], price[position]);
}
});
alertDialogBuilder.setNegativeButton("No",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
//do what you want to do if user clicks cancel.
}
});
AlertDialog alertDialog = alertDialogBuilder.create();
alertDialog.show();
}
});
return rowView;
}
}
DBHandler
public class DBHandler extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "items.db";
public static final String TABLE_PRODUCTS = "items";
public static final String COLUMN_ID = "_id";
public static final String COLUMN_ITEMNAME = "itemName";
public static final String COLUMN_PRICE = "price";
public static final String COLUMN_IMAGE = "image";
public DBHandler(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {
super(context, DATABASE_NAME, factory, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
String query = "CREATE TABLE " + TABLE_PRODUCTS + "(" +
COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
COLUMN_IMAGE + " TEXT, " +
COLUMN_ITEMNAME + " TEXT, " +
COLUMN_PRICE + " TEXT, " +
")";
db.execSQL(query);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP_TABLE_IF_EXISTS " + TABLE_PRODUCTS);
onCreate(db);
}
public void addItem(String img, String desc, String price){
ContentValues values = new ContentValues();
values.put(COLUMN_IMAGE, img);
values.put(COLUMN_ITEMNAME, desc);
values.put(COLUMN_PRICE, price);
SQLiteDatabase db = getWritableDatabase();
db.insert(TABLE_PRODUCTS, null, values);
db.close();
}
public void deleteItem(String itemName){
SQLiteDatabase db = getWritableDatabase();
db.execSQL("DELETE FROM " + TABLE_PRODUCTS + " WHERE " + COLUMN_ITEMNAME + "=\"" + itemName);
}
public String databaseToString() {
String dbString = "";
SQLiteDatabase db = getWritableDatabase();
String query = "SELECT * FROM " + TABLE_PRODUCTS + " WHERE 1";
Cursor c = db.rawQuery(query, null);
c.moveToFirst();
while(!c.isAfterLast()) {
if(c.getString(c.getColumnIndex("itemName")) != null){
dbString += c.getString(c.getColumnIndex("itemName"));
dbString += "\n";
}
}
db.close();
return dbString;
}
}
答案 0 :(得分：1)
将SQLiteDatabase db = getWritableDatabase（）更改为SQLiteDatabase database = context.getWritableDatabase（），我认为这一定是个问题，否则你的插入方法是正确的我猜
答案 1 :(得分：0)
很抱歉，人们在onCreate数据库时遇到错误，而且我输入了一个额外的逗号。
无论如何，谢谢你的帮助。