[TQC+ Android]SQLite 與 MENU 作業_204

Android 2.1 API 7 版本原始題目載點：https://db.tt/BXZjHsRH

僑光科技大學 蔡存孝老師 解說參考：http://rs2.ocu.edu.tw/~tsay/files/TQC204.pdf

GDD02.java - Activity主體

package COM.TQC.GDD02;

import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteCursor;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;

public class GDD02 extends Activity
{
  private mySQLiteOpenHelper gaaSQLiteOpenHelper;
  private Cursor myCursor;
  private ListView myListView;
  private EditText myEditText;
  private int _id;
  protected final static int MENU_ADD = Menu.FIRST;
  protected final static int MENU_EDIT = Menu.FIRST + 1;
  protected final static int MENU_DELETE = Menu.FIRST + 2;

  @Override
  public boolean onOptionsItemSelected(MenuItem item)
  {
    super.onOptionsItemSelected(item);
    switch (item.getItemId())
    {
      case MENU_ADD:
        this.addTodo();
        break;
      case MENU_EDIT:
        this.editTodo();
        break;
      case MENU_DELETE:
        this.deleteTodo();
        break;
    }
    return true;
  }

  @Override
  public boolean onCreateOptionsMenu(Menu menu)
  {
    super.onCreateOptionsMenu(menu);
    //first
    menu.add(0, MENU_ADD, 0, getString(R.string.strAddButton));
    menu.add(0, MENU_EDIT, 0, getString(R.string.strEditButton));
    menu.add(0, MENU_DELETE, 0, getString(R.string.strDeleteButton));
    //
    return true;
  }

  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState)
  {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    myListView = (ListView) this.findViewById(R.id.myListView);
    myEditText = (EditText) this.findViewById(R.id.myEditText);

    gaaSQLiteOpenHelper = new mySQLiteOpenHelper(this);
    
    myCursor = gaaSQLiteOpenHelper.select();

    
    SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, R.layout.list,
        myCursor, new String[]
        { gaaSQLiteOpenHelper.FIELD_TEXT }, new int[]
        { R.id.listTextView1 });
    myListView.setAdapter(adapter);

    
    myListView.setOnItemClickListener(new AdapterView.OnItemClickListener()
    {

      
      public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
          long arg3)
      {
        
        myCursor.moveToPosition(arg2);
        
        _id = myCursor.getInt(0);
        
        myEditText.setText(myCursor.getString(1));
      }

    });
   

  }

  private void addTodo()
  {
   //second call  gaaSQLiteOpenHelper SQL insert method
   gaaSQLiteOpenHelper.insert(myEditText.getText().toString());
   myCursor.requery();
   
 //  
  }

  private void editTodo()
  {
    
 //second call  gaaSQLiteOpenHelper SQL update method
   gaaSQLiteOpenHelper.update(_id, myEditText.getText().toString());
   myCursor.requery();
 //
   
  }

  private void deleteTodo()
  {
 //second call  gaaSQLiteOpenHelper SQL delete method
   gaaSQLiteOpenHelper.delete(_id);
   myCursor.requery();
 //
   
  }
}

mySQLiteOpenHelper

package COM.TQC.GDD02;

import java.nio.charset.CodingErrorAction;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class mySQLiteOpenHelper extends SQLiteOpenHelper
{
  private final static String DATABASE_NAME = "todo_db";
  private final static int DATABASE_VERSION = 1;
  private final static String TABLE_NAME = "todo_table";
  public final static String FIELD_id = "_id";
  public final static String FIELD_TEXT = "todo_text";

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

  @Override
  public void onCreate(SQLiteDatabase db)
  {
    
    String sql = "CREATE TABLE " + TABLE_NAME + " (" + FIELD_id
        + " INTEGER primary key autoincrement, " + " " + FIELD_TEXT + " text)";
    db.execSQL(sql);
  }

  @Override
  public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
  {
    String sql = "DROP TABLE IF EXISTS " + TABLE_NAME;
    db.execSQL(sql);
    onCreate(db);
  }

  public Cursor select()
  {
    SQLiteDatabase db = this.getReadableDatabase();
    Cursor cursor = db.query(TABLE_NAME, null, null, null, null, null, null);
    return cursor;
  }

  public void insert(String text)
  {
    SQLiteDatabase db = this.getWritableDatabase();
    // add date
    ContentValues cv = new ContentValues();
    cv.put(FIELD_TEXT, text);
    db.insert(TABLE_NAME, null, cv);
    //
    
  }

  public void delete(int id)
  {
    SQLiteDatabase db = this.getWritableDatabase();
    //
    String where = FIELD_id + " = " + id;
    // delete date
    db.delete(TABLE_NAME, where, null);
    //
    
  }

  public void update(int id, String text)
  {
    SQLiteDatabase db = this.getWritableDatabase();
    //
    String where = FIELD_id + " = " + id;
    // update date
    ContentValues cv = new ContentValues();
    cv.put(FIELD_TEXT, text);
    
    db.update(TABLE_NAME, cv, where, null);
    
    //
    
  }
}

以下圖片為android程式建立的database所在位置