SQLiteデータベースからアイテムを削除する

Question

連絡先リストのように動作するプログラムを作成しました。これまでのところ、私は連絡先を追加または更新できましたが、私は連絡先を削除することができません。私はどこに問題があるのか​​分からない。 DisplayContactクラスに入ると、ForceCloseが発生します。

マイDisplayContactコード：

public class DisplayContact extends Activity { 

int from_Where_I_Am_Coming = 0; 
    private DBHelper mydb ; 

    TextView name ; 
    TextView phone; 
    TextView email; 
    TextView street; 
    TextView place; 
    int id_To_Update = 0; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_display_contact); 
     name = (TextView) findViewById(R.id.editTextName); 
     phone = (TextView) findViewById(R.id.editTextPhone); 
     email = (TextView) findViewById(R.id.editTextStreet); 
     street = (TextView) findViewById(R.id.editTextEmail); 
     place = (TextView) findViewById(R.id.editTextCity); 

     mydb = new DBHelper(this); 

     Bundle extras = getIntent().getExtras(); 
     if(extras !=null) { 
      int Value = extras.getInt("id"); 

      if(Value>0){ 
       //means this is the view part not the add contact part. 
       Cursor rs = mydb.getData(Value); 
       id_To_Update = Value; 
       rs.moveToFirst(); 

       String nam = rs.getString(rs.getColumnIndex(DBHelper.CONTACTS_COLUMN_NAME)); 
       String phon = rs.getString(rs.getColumnIndex(DBHelper.CONTACTS_COLUMN_PHONE)); 
       String emai = rs.getString(rs.getColumnIndex(DBHelper.CONTACTS_COLUMN_EMAIL)); 
       String stree = rs.getString(rs.getColumnIndex(DBHelper.CONTACTS_COLUMN_STREET)); 
       String plac = rs.getString(rs.getColumnIndex(DBHelper.CONTACTS_COLUMN_CITY)); 

       if (!rs.isClosed()) { 
        rs.close(); 
       } 
       Button b = (Button)findViewById(R.id.button1); 
       b.setVisibility(View.VISIBLE); 

       name.setText((CharSequence)nam); 
       name.setFocusable(true); 
       name.setClickable(true); 

       phone.setText((CharSequence)phon); 
       phone.setFocusable(true); 
       phone.setClickable(true); 

       email.setText((CharSequence)emai); 
       email.setFocusable(false); 
       email.setClickable(false); 

       street.setText((CharSequence)stree); 
       street.setFocusable(false); 
       street.setClickable(false); 

       place.setText((CharSequence)plac); 
       place.setFocusable(false); 
       place.setClickable(false); 
      } 

      Button b2 = (Button)findViewById(R.id.button2); 
      b2.setVisibility(View.VISIBLE); 

      name.setText((CharSequence)name); 
      name.setFocusable(true); 
      name.setClickable(true); 

      phone.setText((CharSequence)phone); 
      phone.setFocusable(true); 
      phone.setClickable(true); 

      email.setText((CharSequence)email); 
      email.setFocusable(false); 
      email.setClickable(false); 

      street.setText((CharSequence)street); 
      street.setFocusable(false); 
      street.setClickable(false); 

      place.setText((CharSequence)place); 
      place.setFocusable(false); 
      place.setClickable(false); 
     } 
    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     Bundle extras = getIntent().getExtras(); 

     if(extras !=null) { 
      int Value = extras.getInt("id"); 
      if(Value>0){ 
       getMenuInflater().inflate(R.menu.display_contact, menu); 
      } else{ 
       getMenuInflater().inflate(R.menu.main_menu, menu); 
      } 
     } 
     return true; 
    } 

    public boolean onOptionsItemSelected(MenuItem item) { 
     super.onOptionsItemSelected(item); 
     switch(item.getItemId()) { 
      case R.id.Edit_Contact: 

       Button b = (Button)findViewById(R.id.button1); 
       b.setVisibility(View.VISIBLE); 

       name.setEnabled(true); 
       name.setFocusableInTouchMode(true); 
       name.setClickable(true); 

       phone.setEnabled(true); 
       phone.setFocusableInTouchMode(true); 
       phone.setClickable(true); 

       email.setEnabled(true); 
       email.setFocusableInTouchMode(true); 
       email.setClickable(true); 

       street.setEnabled(true); 
       street.setFocusableInTouchMode(true); 
       street.setClickable(true); 

       place.setEnabled(true); 
       place.setFocusableInTouchMode(true); 
       place.setClickable(true); 


      case R.id.Delete_Contact: 

       Button b1 = (Button)findViewById(R.id.button2); 
       b1.setVisibility(View.VISIBLE); 

       AlertDialog.Builder builder = new AlertDialog.Builder(this); 
       builder.setMessage(R.string.deleteContact) 
         .setPositiveButton(R.string.yes, new DialogInterface.OnClickListener() { 
          public void onClick(DialogInterface dialog, int id) { 
           mydb.deleteContact(id_To_Update); 
           Toast.makeText(getApplicationContext(), "Deleted Successfully", 
             Toast.LENGTH_SHORT).show(); 
           Intent intent = new Intent(getApplicationContext(),MainActivity.class); 
           startActivity(intent); 
          } 
         }) 
         .setNegativeButton(R.string.no, new DialogInterface.OnClickListener() { 
          public void onClick(DialogInterface dialog, int id) { 

          } 
         }); 

       AlertDialog d = builder.create(); 
       d.setTitle("Are you sure"); 
       d.show(); 

       return true; 
      default: 
       return super.onOptionsItemSelected(item); 

     } 
    } 

    public void run(View view) { 
     Bundle extras = getIntent().getExtras(); 
     if(extras !=null) { 
      int Value = extras.getInt("id"); 
      if(Value>0){ 
       if(mydb.updateContact(id_To_Update,name.getText().toString(), 
         phone.getText().toString(), email.getText().toString(), 
         street.getText().toString(), place.getText().toString())){ 
        Toast.makeText(getApplicationContext(), "Updated", Toast.LENGTH_SHORT).show(); 
        Intent intent = new Intent(getApplicationContext(),MainActivity.class); 
        startActivity(intent); 
       } else{ 
        Toast.makeText(getApplicationContext(), "not Updated", Toast.LENGTH_SHORT).show(); 
       } 
      } else{ 
       if(mydb.insertContact(name.getText().toString(), phone.getText().toString(), 
         email.getText().toString(), street.getText().toString(), 
         place.getText().toString())){ 
        Toast.makeText(getApplicationContext(), "done", 
          Toast.LENGTH_SHORT).show(); 
       } else{ 
        Toast.makeText(getApplicationContext(), "not done", 
          Toast.LENGTH_SHORT).show(); 
       } 
       Intent intent = new Intent(getApplicationContext(),MainActivity.class); 
       startActivity(intent); 
      } 
     } 
    } 
} 

Answer 1

ないあなたが削除されますが、データベースヘルパーファイルに私はこのようなものを作っていたものを確認してください。

public void deleteRecordID(int id){ 
    String query = "DELETE FROM "+ TABLE_NAME +" WHERE " + ID+" = "+id; 
    SQLiteDatabase db = this.getWritableDatabase(); 
    db.execSQL(query); 
    db.close(); 
} 

と以下のIDに値を渡し、私はあなたつかん方法を見つけることができませんでしたが、これはあなたがsqliteのdatabseから取り外すことができる方法である

DatabaseHelper db; 
db = new DatabaseHelper(v.getContext()); 
db.deleteRecordID(id); 

Answer 2

私MainActivityコード：

public final static String EXTRA_MESSAGE = "MESSAGE"; 
private ListView obj; 
DBHelper mydb; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 

    mydb = new DBHelper(this); 
    ArrayList array_list = mydb.getAllCotacts(); 
    ArrayAdapter arrayAdapter=new ArrayAdapter(this,android.R.layout.simple_list_item_1, array_list); 

    obj = (ListView)findViewById(R.id.listView1); 
    obj.setAdapter(arrayAdapter); 
    obj.setOnItemClickListener(new OnItemClickListener(){ 
     @Override 
     public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,long arg3) { 
      // TODO Auto-generated method stub 
      int id_To_Search = arg2 + 1; 

      Bundle dataBundle = new Bundle(); 
      dataBundle.putInt("id", id_To_Search); 

      Intent intent = new Intent(getApplicationContext(),DisplayContact.class); 

      intent.putExtras(dataBundle); 
      startActivity(intent); 
     } 
    }); 
} 

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

@Override 
public boolean onOptionsItemSelected(MenuItem item){ 
    super.onOptionsItemSelected(item); 

    switch(item.getItemId()) { 
     case R.id.item1:Bundle dataBundle = new Bundle(); 
      dataBundle.putInt("id", 0); 

      Intent intent = new Intent(getApplicationContext(),DisplayContact.class); 
      intent.putExtras(dataBundle); 

      startActivity(intent); 
      return true; 
     default: 
      return super.onOptionsItemSelected(item); 
    } 
} 

public boolean onKeyDown(int keycode, KeyEvent event) { 
    if (keycode == KeyEvent.KEYCODE_BACK) { 
     moveTaskToBack(true); 
    } 
    return super.onKeyDown(keycode, event); 
} 

}