我试图通过点击来删除一行,但它不会删除它。
这是我的DataListActivity
package ie.example.artur.projectrepeat;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;
public class DataListActivity extends AppCompatActivity implements AdapterView.OnItemClickListener {
ListView listView;
SQLiteDatabase sqLiteDatabase;
DatabaseClass database;
Cursor cursor;
ListDataAdapter listDataAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.data_list_layout);
listView = (ListView) findViewById(R.id.list_view);
listDataAdapter = new ListDataAdapter(getApplicationContext(),R.layout.row_layout);
listView.setAdapter(listDataAdapter);
database = new DatabaseClass(getApplicationContext());
sqLiteDatabase = database.getReadableDatabase();
cursor = database.getInformation(sqLiteDatabase);
if(cursor.moveToFirst())
{
do {
String id,product_name,category;
id= cursor.getString(0);
product_name=cursor.getString(1);
category=cursor.getString(2);
DataProvider dataProvider = new DataProvider(id,product_name,category);
listDataAdapter.add(dataProvider);
}while(cursor.moveToNext());
}
}
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
TextView tv= (TextView) view.findViewById(R.id.product_id);
DatabaseClass.DeleteInformation(tv.getText().toString(),sqLiteDatabase);
listDataAdapter.notifyDataSetChanged();
}
}
这是DataProvider
课程
package ie.example.artur.projectrepeat;
/**
* Created by family on 10/08/2016.
*/
public class DataProvider {
private String id;
private String product_name;
private String category;
public DataProvider(String id,String product_name,String category)
{
this.id = id;
this.product_name=product_name;
this.category=category;
}
public String getCategory() {
return category;
}
public void setCategory(String category) {
this.category = category;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getProduct_name() {
return product_name;
}
public void setProduct_name(String product_name) {
this.product_name = product_name;
}
}
这是我的Database
班级
package ie.example.artur.projectrepeat;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteQueryBuilder;
/**
* Created by family on 06/07/2016.
*/
public class DatabaseClass extends SQLiteOpenHelper {
public static final String DATABASE_Name = "Product.db2";
public static final String Table_Name = "product_table2";
public static final String COL_1 = "ID";
public static final String COL_2 = "Name";
public static final String COL_3 = "Quantity";
public static final String COL_4 = "Category";
public static final String COL_5 = "Importance";
public DatabaseClass(Context context) {
super(context, DATABASE_Name, null, 1);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table " + Table_Name + " (ID INTEGER PRIMARY KEY AUTOINCREMENT,NAME TEXT,Quantity TEXT,Category INTEGER,Importance TEXT);");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("Drop Table If Exists" + Table_Name);
onCreate(db);
}
public boolean insertData(String name, String quantity, String category,String importance) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(COL_2, name);
contentValues.put(COL_3, quantity);
contentValues.put(COL_4, category);
contentValues.put(COL_5, importance);
long result = db.insert(Table_Name, null, contentValues);
if (result == -1)
return false;
else
return true;
}
public Cursor getAllData() {
SQLiteDatabase db = this.getWritableDatabase();
Cursor res = db.rawQuery("select * from " + Table_Name, null);
return res;
}
public boolean updateData(String id,String name,String quantity,String category,String importance ) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(COL_1, id);
contentValues.put(COL_2, name);
contentValues.put(COL_3, quantity);
contentValues.put(COL_4, category);
contentValues.put(COL_5, importance);
db.update(Table_Name,contentValues,"id =?",new String[]{id});
return true;
}
/* public Cursor getCursor(){
SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();
queryBuilder.setR
}
*/
public Integer DeleteData (String id) {
SQLiteDatabase db = this.getWritableDatabase();
return db.delete(Table_Name,"ID = ?",new String[]{id});
}
public static void DeleteInformation(String item_name,SQLiteDatabase sqLiteDatabase){
String selection = COL_1+" LIKE ?";
String [] selection_args = {item_name};
sqLiteDatabase.delete(Table_Name,selection,selection_args);
}
public Cursor getInformation(SQLiteDatabase sqLiteDatabase)
{
Cursor cursor;
String [] Projections = {COL_1,COL_2,COL_4};
cursor = sqLiteDatabase.query(Table_Name,Projections,null,null,null,null,null);
return cursor;
}
public Cursor getItem(String item_name ,SQLiteDatabase sqLiteDatabase){
String [] Projections = {COL_1,COL_2,COL_3,COL_4,COL_5};
String selection = COL_1+" LIKE ?";
String [] selection_args = {item_name};
Cursor cursor = sqLiteDatabase.query(Table_Name,Projections,selection,selection_args,null,null,null);
return cursor;
}
* ListDataAdapter *
package ie.example.artur.projectrepeat;
import android.content.Context;
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.TextView;
import java.util.ArrayList;
import java.util.List;
/**
* Created by family on 10/08/2016.
*/
public class ListDataAdapter extends ArrayAdapter {
List list = new ArrayList ();
public ListDataAdapter(Context context, int resource) {
super(context, resource);
}
static class LayoutHandler
{
TextView id,product_name,category;
}
@Override
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) {
LayoutHandler layoutHandler;
View row = convertView;
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.id = (TextView) row.findViewById(R.id.product_id);
layoutHandler.product_name = (TextView) row.findViewById(R.id.product_name);
layoutHandler.category = (TextView) row.findViewById(R.id.product_category);
row.setTag(layoutHandler);
}
else {
layoutHandler = (LayoutHandler) row.getTag();
}
DataProvider dataProvider = (DataProvider) this.getItem(position);
layoutHandler.id.setText(dataProvider.getId());
layoutHandler.product_name.setText(dataProvider.getProduct_name());
layoutHandler.category.setText(dataProvider.getCategory());
return row;
}
}
}