リストビュー項目をsqliteテーブルの名前で削除する方法

Question

削除ボタンがあるリストビュー項目を削除することはできません。今すぐ、ボタンを押すと、最初のアイテムが削除されます。誰か助けてくれますか？

Locatie

package com.buysse.roan.findyourstuff; 

import android.content.ClipData; 
import android.content.Context; 
import android.content.Intent; 
import android.content.SharedPreferences; 
import android.database.Cursor; 
import android.os.Bundle; 
import android.util.Log; 
import android.util.SparseBooleanArray; 
import android.view.View; 
import android.support.design.widget.NavigationView; 
import android.support.v4.view.GravityCompat; 
import android.support.v4.widget.DrawerLayout; 
import android.support.v7.app.ActionBarDrawerToggle; 
import android.support.v7.app.AppCompatActivity; 
import android.support.v7.widget.Toolbar; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.view.View.OnClickListener; 
import android.widget.AdapterView; 
import android.widget.ArrayAdapter; 
import android.widget.Button; 
import android.widget.EditText; 
import android.widget.ListView; 
import android.widget.TextView; 

import java.util.ArrayList; 
import java.util.List; 


public class Locatie extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener, OnClickListener { 


    private Button buttonSave; 
    private Button buttonDelete; 
    private EditText editTextName; 
    private EditText editTextLocation; 
    MySQLiteHelper db = new MySQLiteHelper(this); 





    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_locatie); 
     try{filList(); 
      List<Item> list = db.getAllItems();} 
     catch(IndexOutOfBoundsException e){ System.out.println("caught");} 
     //add all items to list 
     //if(i>0){ 
     //filList(); 
     //List<Item> list = db.getAllItems(); 
     //db.deleteItem(list.get(0));} 

     /** 
     * CRUD Operations 
     * 
     */ 

     //buttonpress 
     buttonSave = (Button) findViewById(R.id.buttonAddUser); 
     buttonSave.setOnClickListener(this); 
     editTextName = (EditText) findViewById(R.id.editTextName); 
     editTextLocation = (EditText) findViewById(R.id.editTextLocation); 











     // add item 

     // get all items 


     // get all items 

     //db.getAllItems(); 

     ///new activity remove 



//toolbar 

     Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
     setSupportActionBar(toolbar); 


     DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
     ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
       this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close); 
     drawer.setDrawerListener(toggle); 
     toggle.syncState(); 

     NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view); 
     navigationView.setNavigationItemSelectedListener(this); 
    } 

    @Override 
    public void onBackPressed() { 
     DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
     if (drawer.isDrawerOpen(GravityCompat.START)) { 
      drawer.closeDrawer(GravityCompat.START); 
     } else { 
      super.onBackPressed(); 
     } 
    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.locatie, menu); 
     return true; 
    } 

    @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(); 


     return super.onOptionsItemSelected(item); 
    } 

    //change links 
    @SuppressWarnings("StatementWithEmptyBody") 
    @Override 
    public boolean onNavigationItemSelected(MenuItem item) { 
     // Handle navigation view item clicks here. 
     int id = item.getItemId(); 

     if (id == R.id.nav_Locatie) { 
      Intent Locatie = new Intent(this, Locatie.class); 
      startActivity(Locatie); 
     } else if (id == R.id.nav_objects) { 
      Intent Object = new Intent(this, Object.class); 
      startActivity(Object); 
     } 

     DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
     drawer.closeDrawer(GravityCompat.START); 
     return true; 
    } 

    @Override 
    protected void onStop() { 
     super.onStop(); 
    } 

    @Override 
    protected void onResume() { 
     super.onResume(); 

    } 


// onclick add to array + refresh list 
    @Override 
    public void onClick(View view) { 

     if (view.getId() == R.id.buttonAddUser) { 
      db.addItem(new Item(editTextName.getText().toString(), editTextLocation.getText().toString())); 

      /////Make Method 
      try{filList();} 
      catch(IndexOutOfBoundsException e){ System.out.println("caught");} 
     } 
    } 

     public void filList(){ 
      MyAdapter adapter = new MyAdapter(this, db.getAllItems()); 
     ListView listView = (ListView) findViewById(R.id.listView); 
     listView.setAdapter(adapter); 

    } 

//list delete 
    public void deleteItem (View view){ 
     List<Item> list = db.getAllItems(); 
       ArrayList items = db.getAllItems(); 
       db.deleteItem(list.get(0)); 

     try{filList();} 
     catch(IndexOutOfBoundsException e){ System.out.println("caught");}// 
    } 




} 

content_locatie

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:paddingBottom="@dimen/activity_vertical_margin" 
    android:paddingLeft="@dimen/activity_horizontal_margin" 
    android:paddingRight="@dimen/activity_horizontal_margin" 
    android:paddingTop="@dimen/activity_vertical_margin" 
    app:layout_behavior="@string/appbar_scrolling_view_behavior" 
    tools:context="com.buysse.roan.findyourstuff.Locatie" 
    tools:showIn="@layout/app_bar_locatie" 
    android:weightSum="1"> 


    <TableLayout 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:layout_alignParentTop="true" 
     android:layout_alignParentLeft="true" 
     android:layout_alignParentStart="true" 
     android:stretchColumns="1" 
     android:id="@+id/tableLayout"> 

     <TableRow 
      android:layout_width="match_parent" 
      android:layout_height="match_parent"> 

      <TextView 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:textAppearance="?android:attr/textAppearanceLarge" 
       android:text="@string/textViewNameText" 
       android:id="@+id/textViewName" /> 

      <EditText 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:id="@+id/editTextName" /> 

     </TableRow> 


     <TableRow 
      android:layout_width="match_parent" 
      android:layout_height="match_parent"> 

     </TableRow> 
    </TableLayout> 
    <ListView 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:id="@+id/listView" 
     android:layout_below="@+id/buttonAddUser" 
     android:layout_alignParentLeft="true" 
     android:layout_alignParentStart="true" 
     android:longClickable="true" 
     android:choiceMode="multipleChoice" /> 

    <Button 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="@string/buttonAddText" 
     android:id="@+id/buttonAddUser" 
     android:layout_span="2" 
     android:layout_below="@+id/tableLayout" 
     android:layout_alignParentLeft="true" 
     android:layout_alignParentStart="true" 
     android:layout_marginTop="54dp" 
     android:layout_toStartOf="@+id/editTextLocation" 
     android:layout_alignRight="@+id/listView" 
     android:layout_alignEnd="@+id/listView" 
     android:layout_toLeftOf="@+id/editTextLocation" /> 

    <TextView 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:textAppearance="?android:attr/textAppearanceLarge" 
     android:id="@+id/textViewLocation" 
     android:layout_alignBottom="@+id/editTextLocation" 
     android:layout_alignParentLeft="true" 
     android:layout_alignParentStart="true" 
     android:text="@string/textViewLocation" 
     /> 

    <EditText 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:id="@+id/editTextLocation" 
     android:layout_below="@+id/tableLayout" 
     android:layout_alignRight="@+id/tableLayout" 
     android:layout_alignEnd="@+id/tableLayout" 
     android:layout_toEndOf="@+id/textViewLocation" 
     android:layout_toRightOf="@+id/textViewLocation" /> 

行カスタムレイアウトリストビュー

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:orientation="vertical" 
    android:weightSum="1"> 

    <RelativeLayout 
     android:layout_width="match_parent" 
     android:layout_height="match_parent"> 

     <TextView 
      android:id="@+id/Name" 
      android:layout_width="match_parent" 
      android:layout_height="wrap_content" 
      android:text="Study cursors" 
      android:textAppearance="?android:attr/textAppearanceLarge" 
      android:longClickable="true" 
      android:layout_alignRight="@+id/button" 
      android:layout_alignEnd="@+id/button" /> 

     <TextView 
      android:id="@+id/Location" 
      android:layout_width="388dp" 
      android:layout_height="wrap_content" 
      android:text="3" 
      android:textAppearance="?android:attr/textAppearanceMedium" 
      android:layout_weight="0.07" 
      android:longClickable="true" 
      android:layout_below="@+id/Name" 
      android:layout_toLeftOf="@+id/button" 
      android:layout_toStartOf="@+id/button" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:text="Delete" 
      android:id="@+id/button" 
      android:onClick="deleteItem" 
      android:layout_alignParentTop="true" 
      android:layout_alignParentRight="true" 
      android:layout_alignParentEnd="true" /> 

    </RelativeLayout> 

</LinearLayout> 

///////////////////////// Locatie（頼まれた）

//list delete 
    public void deleteItem (View view){ 
     List<Item> list = db.getAllItems(); 
       ArrayList items = db.getAllItems(); 
       db.deleteItem(list.get(0)); 

     try{filList();} 
     catch(IndexOutOfBoundsException e){ System.out.println("caught");}}} 

に削除する +メソッドSqlitehelper ///////////////////////////////////////////////////////////////// ///////////////////////////////////////////////////////////////// ////////////////////////////////

package com.buysse.roan.findyourstuff; 

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 android.widget.ListView; 

import java.lang.*; 
import java.util.ArrayList; 
import java.util.LinkedList; 
import java.util.List; 

/** 
* Created by roanb on 10/08/2016. 
*/ 
public class MySQLiteHelper extends SQLiteOpenHelper { // Database Version 
    private static final int DATABASE_VERSION = 1; 
    // Database Name 
    private static final String DATABASE_NAME = "ItemDB"; 

    public MySQLiteHelper(Context context) { 
     super(context, DATABASE_NAME, null, DATABASE_VERSION); 
    } 

    @Override 
    public void onCreate(SQLiteDatabase db) { 
     // SQL statement to create book table 
     String CREATE_ITEM_TABLE = "CREATE TABLE items (" + 
       "id INTEGER PRIMARY KEY AUTOINCREMENT, " + 
       "name TEXT, "+ 
       "location TEXT)"; 

     // create items table 
     db.execSQL(CREATE_ITEM_TABLE); 
    } 

    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
     // Drop older items if existed 
     db.execSQL("DROP TABLE IF EXISTS items"); 

     // create fresh items table 
     this.onCreate(db); 
    } 

    //sql statements 

    // items table name 
    private static final String TABLE_ITEMS = "items"; 

    // items Table Columns names 
    private static final String KEY_ID = "id"; 
    private static final String KEY_NAME = "name"; 
    private static final String KEY_LOCATION = "location"; 

    private static final String[] COLUMNS = {KEY_ID,KEY_NAME,KEY_LOCATION}; 

    public void addItem (Item item){ 
     //for logging 
     Log.d("addItem", item.toString()); 

     // 1. get reference to writable DB 
     SQLiteDatabase db = this.getWritableDatabase(); 

     // 2. create ContentValues to add key "column"/value 
     ContentValues values = new ContentValues(); 
     values.put(KEY_NAME, item.getName()); // get name 
     values.put(KEY_LOCATION, item.getLocation()); // get author 

     // 3. insert 
     db.insert(TABLE_ITEMS, // table 
       null, //nullColumnHack 
       values); // key/value -> keys = column names/ values = column values 

     // 4. close 
     db.close(); 
    } 

    public Item getItem(int id){ 

     // 1. get reference to readable DB 
     SQLiteDatabase db = this.getReadableDatabase(); 

     // 2. build query 
     Cursor cursor = 
       db.query(TABLE_ITEMS, // a. table 
         COLUMNS, // 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); // h. limit 

     // 3. if we got results get the first one 
     if (cursor != null) 
      cursor.moveToFirst(); 

     // 4. build item object 
     Item item = new Item(); 
     item.setId(Integer.parseInt(cursor.getString(0))); 
     item.setName(cursor.getString(1)); 
     item.setLocation(cursor.getString(2)); 

     //log 
     Log.d("geItem("+id+")", item.toString()); 

     // 5. return book 
     return item; 
    } 

    public ArrayList<Item> getAllItems() { 
     ArrayList<Item> items = new ArrayList<>(); 

     // 1. build the query 
     String query = "SELECT * FROM " + TABLE_ITEMS; 

     // 2. get reference to writable DB 
     SQLiteDatabase db = this.getWritableDatabase(); 
     Cursor cursor = db.rawQuery(query, null); 

     // 3. go over each rowl, build item and add it to list 
     Item item = null; 
     if (cursor.moveToFirst()) { 
      do { 
       item = new Item(); 
       item.setId(Integer.parseInt(cursor.getString(0))); 
       item.setName(cursor.getString(1)); 
       item.setLocation(cursor.getString(2)); 

       // Add item to items 
       items.add(item); 
      } while (cursor.moveToNext()); 
     } 
     Log.d("getAllItems()", items.toString()); 

     // return items 
     return items; 
    } 

    public int updateItem(Item item) { 

     // 1. get reference to writable DB 
     SQLiteDatabase db = this.getWritableDatabase(); 

     // 2. create ContentValues to add key "column"/value 
     ContentValues values = new ContentValues(); 
     values.put("name", item.getName()); // get title 
     values.put("location", item.getLocation()); // get author 

     // 3. updating rowl 
     int i = db.update(TABLE_ITEMS, //table 
       values, // column/value 
       KEY_ID+" = ?", // selections 
       new String[] { String.valueOf(item.getId()) }); //selection args 

     // 4. close 
     db.close(); 

     return i; 

    } 

    public void deleteItem(Item item) { 

     // 1. get reference to writable DB 
     SQLiteDatabase db = this.getWritableDatabase(); 

     // 2. delete 
     db.delete(TABLE_ITEMS, //table name 
       KEY_ID+" = ?", // selections 
       new String[] { String.valueOf(item.getId()) }); //selections args 

     // 3. close 
     db.close(); 

     //log 
     Log.d("deleteItem",item.toString()); 

    } 




} 

MyAdapter

private final Context context; 
    private final ArrayList<Item> itemsArrayList; 

    public MyAdapterL(Context context, ArrayList<Item> itemsArrayList) { 

     super(context, R.layout.rowl, itemsArrayList); 

     this.context = context; 
     this.itemsArrayList = itemsArrayList; 
    } 

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

     // 1. Create inflater 
     LayoutInflater inflater = (LayoutInflater) context 
       .getSystemService(Context.LAYOUT_INFLATER_SERVICE); 

     // 2. Get rowView from inflater 
     View rowView = inflater.inflate(R.layout.rowl, parent, false); 

     // 3. Get the two text view from the rowView 
     TextView labelView = (TextView) rowView.findViewById(R.id.Location); 
     TextView valueView = (TextView) rowView.findViewById(R.id.Name); 

     // 4. Set the text for textView 
     labelView.setText(itemsArrayList.get(position).getName()); 
     valueView.setText(itemsArrayList.get(position).getLocation()); 

     // 5. retrn rowView 
     return rowView; 
    } 
} 

Answer 1

ListViewクラスの使用が最適ではないため、データセットが変更されるたびにMyAdapterを再構築しないでください。あなたはDBの場合はバッキングデータセットを変更してから、adapter.notifyDataSetChanged（）を呼び出す必要があります。

db.deleteItem(list.get(0)); 

あなたはリストビューからデータを削除しないでください、あなたはから必要なデータを削除します。

は常に削除される最初のデータ項目については、私はあなたが常に索引項目0からだと言うだろうDB、SQLクエリを使用して、アダプタを更新します。

Answer 2

名前を使用してSQLiteテーブルからデータを削除することは、名前が一意である限り理想的な方法ではありません。

1. あなたのアクティビティでは、deleteItem（id（またはname））のパブリック関数を作成できます。

2. アダプタをグローバル変数にします。

3. コンテキストではなくMyAdapterでアクティビティを渡します。

4. アダプタのgetViewで、setOnClickListenerを削除ボタンに設定します。 onClickでは、あなたのアクティビティのdeleteItem（id）関数を呼び出します。

5. deleteItem（id）関数で、最後にmyAdapter.notifyDataSetChanged（）を追加します。

おかげ