当用户长按listview中的某个项目时，我目前无法删除一行。我一次只能删除一行，这是我想要的，但当我删除前几个项时，它是成功的，当我尝试删除具有较晚ID的项目时。 id不会被删除并保留。我需要帮助，以便在要删除项目时始终删除项目。感谢。
这是我的数据库助手类
package com.example.health.adapter;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
import com.example.health.dao.ExerciseDAO;
import com.example.health.dao.RecipeDAO;
import java.util.ArrayList;
import java.util.List;
public class MySQLiteHelper extends SQLiteOpenHelper {
// Database Version
private static final int DATABASE_VERSION = 1;
// Database Name
private static final String DATABASE_NAME = "HealthDB";
public MySQLiteHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_RECIPE_TABLE = "CREATE TABLE recipe ( " +
"id INTEGER PRIMARY KEY AUTOINCREMENT, " +
"title TEXT, " +
"description TEXT )";
db.execSQL(CREATE_RECIPE_TABLE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS recipe");
this.onCreate(db);
}
//START OF CRUD FOR RECIPE
private static final String TABLE_RECIPE = "recipe";
//column names
private static final String KEY_RID = "id";
private static final String KEY_RTITLE = "title";
private static final String KEY_RDESCRIPTION = "description";
private static final String[] RCOLUMNS = {KEY_RID,KEY_RTITLE,KEY_RDESCRIPTION};
public void addRecipe(RecipeDAO r) {
Log.d("addRecipe", r.toString());
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_RTITLE, r.getTitle());
values.put(KEY_RDESCRIPTION, r.getDescription());
db.insert(TABLE_RECIPE, null, values);
Log.d("Data Added", r.toString());
db.close();
}
public RecipeDAO getRecipe(int id) {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor =
db.query(TABLE_RECIPE, // a. table
RCOLUMNS, // b. column names
" id = ?", // c. selections
new String[] { String.valueOf(id) }, // d. selections args
null, // e. group by
null, // f. having
null, // g. order by
null);
if (cursor != null)
cursor.moveToFirst();
RecipeDAO r = new RecipeDAO();
r.setRecipeID(Integer.parseInt(cursor.getString(0)));
r.setTitle(cursor.getString(1));
r.setDescription(cursor.getString(2));
Log.d("getRecipe("+id+")", r.toString());
return r;
}
public List<RecipeDAO> getAllRecipe() {
List<RecipeDAO> recipe = new ArrayList<RecipeDAO>();
String query = "SELECT * FROM " + TABLE_RECIPE;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(query, null);
RecipeDAO r = null;
if (cursor.moveToFirst()) {
do {
r = new RecipeDAO();
r.setRecipeID(Integer.parseInt(cursor.getString(0)));
r.setTitle(cursor.getString(1));
r.setDescription(cursor.getString(2));
recipe.add(r);
} while (cursor.moveToNext());
}
Log.d("getAllRecipe()", recipe.toString());
return recipe;
}
public int updateRecipe(RecipeDAO r) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("title", r.getTitle());
values.put("description", r.getDescription());
int i = db.update(TABLE_RECIPE, //table
values, // column/value
KEY_RID+" = ?", // selections
new String[] { String.valueOf(r.getRecipeID()) });
db.close();
return i;
}
public void deleteAllRecipe() {
RecipeDAO r = new RecipeDAO();
SQLiteDatabase db = this.getWritableDatabase();
db.delete(TABLE_RECIPE,null,null);
db.execSQL("DELETE FROM SQLITE_SEQUENCE WHERE NAME = '" + TABLE_RECIPE + "'");
db.close();
Log.d("deleteRecipe", r.toString());
}
/*
public void deleteRecipe(RecipeDAO r) {
SQLiteDatabase db = this.getWritableDatabase();
db.delete(TABLE_RECIPE, KEY_RID+ " = ? ", new String[] { String.valueOf(r.getRecipeID()) });
db.close();
}*/
public boolean deleteRecipe(long id)
{
SQLiteDatabase db = this.getWritableDatabase();
return db.delete(TABLE_RECIPE, KEY_RID + "=" + id, null) > 0;
}
//END OF CRUD FOR RECIPE
}
数据库CRUD操作的类
package com.example.health.recipe;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
import com.example.health.adapter.MySQLiteHelper;
import com.example.health.dao.RecipeDAO;
import com.example.health.healthplanner.R;
import java.util.List;
public class Recipes extends Fragment {
MySQLiteHelper db;
Button deleteButton;
ListView lv;
List<RecipeDAO> data;
RecipeDAO r = new RecipeDAO();
public Recipes() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View v = inflater.inflate(R.layout.recipe_fragment, container, false);
db = new MySQLiteHelper(getActivity());
/*
db.addRecipe(new RecipeDAO("Windows", "Bill Gates"));//hardcode test
db.addRecipe(new RecipeDAO("IOS", "Steve Jobs"));//same
db.addRecipe(new RecipeDAO("Android", "Andy Rubin"));//same*/
data = db.getAllRecipe();
final ArrayAdapter adapter = new ArrayAdapter(getActivity(), android.R.layout.simple_list_item_1, data);
lv = (ListView) v.findViewById(R.id.listView2);
lv.setAdapter(adapter);
lv.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
data.remove(position);
db.deleteRecipe(id + 1);
adapter.notifyDataSetChanged();
return false;
// db.deleteRecipeRow(r.getRecipeID());
//Toast.makeText(getActivity(),"ID = " + r.getRecipeID(), Toast.LENGTH_LONG).show();
}
});
deleteButton = (Button) v.findViewById(R.id.deletebutton);
deleteButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(getActivity());
alertDialog.setTitle("Delete");
alertDialog.setMessage("Are you sure you want to delete all data?");
alertDialog.setCancelable(false);
alertDialog.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
db.deleteAllRecipe();
adapter.notifyDataSetChanged();
Toast.makeText(getActivity(), "All data delete", Toast.LENGTH_SHORT).show();
}
});
alertDialog.setNegativeButton("No", null);
alertDialog.show();
/* data = db.getAllRecipe();
for(RecipeDAO re : data) { testing to see if data is in database
String log = "Id: " + re.getRecipeID() + ", Title: " + re.getTitle();
Log.d("Data", log);
}*/
}
});
return v;
}
}
答案 0 :(得分：1)
试试这个
public void delete(String name) {
db.delete(your_table_name, "name= ?", new String[] { name });
}
答案 1 :(得分：0)
请修改此方法，
//更改setOnItemLongClickListener中的代码
lv.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
data.remove(position);
db.deleteRecipe(id + 1);
data = db.getAllRecipe();
adapter = new ArrayAdapter(getActivity(),android.R.layout.simple_list_item_1, data);
//and call change adapter in listview
adapter.notifyDataSetChanged();
return false;
// db.deleteRecipeRow(r.getRecipeID());
//Toast.makeText(getActivity(),"ID = " + r.getRecipeID(), Toast.LENGTH_LONG).show();
}
});
//这个在sqlite数据库中删除的方法
public boolean deleteRecipe(long id)
{
SQLiteDatabase db = this.getWritableDatabase();
return db.delete(TABLE_RECIPE, KEY_RID + " =?" , new String[]{id}) > 0;
}