Question

Good Day Guys ..在这里需要一些帮助..我在列表视图中删除所选行时遇到了麻烦..我想使用警告对话框确认删除所选行..还要编辑..我是一个初学者，我试图寻找这个问题的答案，并尝试将其与其他问题联系起来，但我仍然没有得到它......

我的DatabaseHelper类

public class DatabaseHelper extends SQLiteOpenHelper implements   Filterable{

// private static final String COLUMN_NAME="ageing_column";
private static final String DATABASE_NAME=" EXPIRATIONMONITORING.DB";
private static final int DATABASE_VERSION = 1;
private static  final String CREATE_QUERY =
        "CREATE TABLE "+ContractClass.NewInfo.TABLE_NAME+"("+ ContractClass.NewInfo.ITEM_ID+" INTEGER PRIMARY KEY AUTOINCREMENT, "+ContractClass.NewInfo.DESCRIPTION+" TEXT, "+
                ContractClass.NewInfo.CATEGORY+" TEXT,"+ ContractClass.NewInfo.MONTHONE+" TEXT, "+ ContractClass.NewInfo.REMIND_AT+" TEXT, "+ ContractClass.NewInfo.QTY+" TEXT, "+
                ContractClass.NewInfo.LOCATION+" TEXT );";
private SQLiteDatabase sqLiteDatabase;

public DatabaseHelper(Context context)
{

    super(context, DATABASE_NAME, null, DATABASE_VERSION);
    //this.context1=context;
    Log.e("DATABASE OPERATIONS", "Database created / opened....");
}
@Override
public void onCreate(SQLiteDatabase db) {


    db.execSQL(CREATE_QUERY);

    Log.e("DATABASE OPERATIONS", "Table created....");

}
public void addInformations(String description, String category, String monthOne,String quantity,String remind, String location, SQLiteDatabase db)
{
    ContentValues contentValues=new ContentValues();
    contentValues.put(ContractClass.NewInfo.LOCATION,location);
    contentValues.put(ContractClass.NewInfo.DESCRIPTION,description);
    contentValues.put(ContractClass.NewInfo.CATEGORY,category);
    contentValues.put(ContractClass.NewInfo.MONTHONE,monthOne);
    contentValues.put(ContractClass.NewInfo.REMIND_AT,remind);
    contentValues.put(ContractClass.NewInfo.QTY,quantity);
    db.insert(ContractClass.NewInfo.TABLE_NAME, null, contentValues);
    Log.e("DATABASE OPERATIONS", "One row inserted");
    db.close();
}

public Cursor getInformations(SQLiteDatabase db)
{
    Cursor cursor;
    String[] projections ={ContractClass.NewInfo.DESCRIPTION,ContractClass.NewInfo.CATEGORY,ContractClass.NewInfo.MONTHONE, ContractClass.NewInfo.QTY, ContractClass.NewInfo.REMIND_AT,ContractClass.NewInfo.LOCATION};
    cursor=db.query(ContractClass.NewInfo.TABLE_NAME, projections, null, null, null, null, null);
    return cursor;
}
public Cursor getContact(String location,SQLiteDatabase sqLiteDatabase)
{
    String[] projections ={ContractClass.NewInfo.DESCRIPTION,ContractClass.NewInfo.CATEGORY,ContractClass.NewInfo.MONTHONE, ContractClass.NewInfo.QTY, ContractClass.NewInfo.REMIND_AT,ContractClass.NewInfo.LOCATION};
    String selection = ContractClass.NewInfo.LOCATION+" LIKE? ";
    String [] sargs={location};
    Cursor cursor=sqLiteDatabase.query(ContractClass.NewInfo.TABLE_NAME,projections,selection,sargs,null,null,null);
    return  cursor;
}
public String[] SelectAllData()
{
    try
    {
        String arrData[]=null;
        SQLiteDatabase db;
        db=this.getReadableDatabase();
        String strSQL=" SELECT "+ ContractClass.NewInfo.LOCATION+" FROM "+ ContractClass.NewInfo.TABLE_NAME;
        Cursor cursor =db.rawQuery(strSQL,null);
        if(cursor !=null)
        {
            if(cursor.moveToFirst())
            {
                arrData=new String[cursor.getCount()];
                int i=0;
                do
                {
                    arrData[i]=cursor.getString(0);
                    i++;

                }while(cursor.moveToNext());
            }
        }
        cursor.close();
        return arrData;

    }catch(Exception e){
        return null;
    }
}
public void delete_byID(int id){
    sqLiteDatabase.delete(ContractClass.NewInfo.TABLE_NAME, ContractClass.NewInfo.ITEM_ID + "=" + id, null);
}
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

}


@Override
public Filter getFilter() {
    return null;
}
}

这是我的主要课程..

 public class ViewListsActivity extends AppCompatActivity {
DatabaseHelper databaseHelper;
SQLiteDatabase sqLiteDatabase;
 ListDataAdapter  listDataAdapter;
 ListView listView;
 Cursor cursor;
 EditText delete_txt;
 String deletetxt;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.view_lists_activity);
    listView = (ListView) findViewById(R.id.search_listView);
           listDataAdapter = new   

    ListDataAdapter(getApplicationContext(),R.layout.row_layout);
    databaseHelper = new DatabaseHelper(getApplicationContext());
    databaseHelper = new DatabaseHelper(this);
    delete_txt = (EditText) findViewById(R.id.delete_text);
    sqLiteDatabase = databaseHelper.getReadableDatabase();
    cursor = databaseHelper.getInformations(sqLiteDatabase);
    listView.setAdapter(listDataAdapter);
    if (cursor.moveToFirst()) {
        do {
            String description, category, month1,remind,qty,location;
            description = cursor.getString(0);
            category = cursor.getString(1);
            month1 = cursor.getString(2);
             qty=cursor.getString(3);
            remind=cursor.getString(4);
            location = cursor.getString(5);
            DataProvider dataProvider = new DataProvider(description,  
            category, month1,qty,remind,location);
            listDataAdapter.add(dataProvider);
        } while (cursor.moveToNext());
    }
    listView.setOnItemLongClickListener(new  
   AdapterView.OnItemLongClickListener() {
        @Override
        public boolean onItemLongClick(AdapterView<?> parent, View  
    view,  int position, long id) {
            return false;




        }
    });
  }
  public void ToSearchBtn(View view)
  {
    Intent intent=new Intent(this,ThirdActivitySearchAllData.class);
    startActivity(intent);
}
public void ToAddNewItemBtn(View view)
{
    Intent intent=new Intent(this,SecondActivitySaveData.class);
    startActivity(intent);
}

}

我的列表适配器类

 public class ListDataAdapter extends ArrayAdapter  {
List list = new ArrayList();

public ListDataAdapter(Context context, int resource) {
    super(context, resource);
}



static class LayoutHandler
{
    TextView DESCRIPTION,CATEGORY,MONTH1,QTY,REMIND,LOCATION;
}
public void add(Object object)
{
    super.add(object);
    list.add(object);
}

@Override
public int getCount() {
    return list.size();
}

@Override
public Object getItem(int position) {
    return list.get(position);
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {

    View row =convertView;
    LayoutHandler layoutHandler;

    if(row==null)
    {
        LayoutInflater layoutInflater=(LayoutInflater)this.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        row=layoutInflater.inflate(R.layout.row_layout,parent,false);
        layoutHandler=new LayoutHandler();

        layoutHandler.DESCRIPTION= (TextView) row.findViewById(R.id.text_description);
        layoutHandler.CATEGORY= (TextView) row.findViewById(R.id.text_category);
        layoutHandler.MONTH1= (TextView) row.findViewById(R.id.text_monthOne);
        layoutHandler.REMIND= (TextView) row.findViewById(R.id.text_remind);
        layoutHandler.QTY= (TextView) row.findViewById(R.id.text_qty);
        layoutHandler.LOCATION= (TextView) row.findViewById(R.id.text_location);
        row.setTag(layoutHandler);
    }else
    {
        layoutHandler=(LayoutHandler)row.getTag();

    }
    DataProvider dataProvider= (DataProvider) this.getItem(position);
    layoutHandler.DESCRIPTION.setText(dataProvider.getDescription());
    layoutHandler.CATEGORY.setText(dataProvider.getCategory());
    layoutHandler.MONTH1.setText(dataProvider.getMonthOne());
    layoutHandler.REMIND.setText(dataProvider.getRemindAt());
    layoutHandler.QTY.setText(dataProvider.getQuantity());
     layoutHandler.LOCATION.setText(dataProvider.getLocation());


    return row;
}


 }

Answer 1

您可以使用ALERT DIALOG显示确认弹出窗口，使用YES / NO选项进行删除和编辑，并根据ALERT DIALOG中选择的选项执行进一步操作

在以下链接中，您可以找到示例代码

How do I display an alert dialog on Android?

警报对话框删除ListView项目上的一行单击

1 个答案: