Android实例二:手机数据库SQListe

[code="java"]SQLiteActivity.java

public class SQLiteActivity extends Activity {
     private ToDoDB myToDoDB;
     private Cursor myCurson;
     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);
    //添加三个MENU
    menu.add(Menu.NONE,MENU_ADD,0,R.string.strAddButton);
    menu.add(Menu.NONE,MENU_EDIT,0,R.string.strEditButton);
    menu.add(Menu.NONE,MENU_DELETE,0,R.string.strDeleteButton);
    return true;
     }    
    @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);
        myToDoDB = new ToDoDB(this);
        //取得DataBase里的数据
        myCurson = myToDoDB.select();
        //new  SimpleCursonAdapter并将myCursor传入，显示 数据的字段为todo_text
        SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,R.layout.list,myCurson,new String[]{
        ToDoDB.FIELD_TEXT},new int[]{R.id.listTextView1});
        myListView.setAdapter(adapter);
        //将myListView添加OnItemClickListener
        myListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {

@Override
public void onItemClick(AdapterView> arg0, View arg1, int arg2,
long arg3) {
  //将myCurson移到所单击的值
myCurson.moveToPosition(arg2);
//取得字段_id的值
_id = myCurson.getInt(0);
//取得字段todo_text的值
myEditText.setText(myCurson.getString(1));

}
       
});
       
        myListView.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {

@Override
public void onItemSelected(AdapterView> arg0, View arg1,
int arg2, long arg3) {
SQLiteCursor sc=(SQLiteCursor)arg0.getSelectedItem();
_id = sc.getInt(0);
myEditText.setText(sc.getString(1));

}

@Override
public void onNothingSelected(AdapterView> arg0) {
// TODO Auto-generated method stub

}
});
       
    }
   
   
   
    private void addTodo(){
       if(myEditText.getText().toString().equals(""))
    return ;
       //添加数据到数据库
       myToDoDB.insert(myEditText.getText().toString());
       //重新查询
       myCurson.requery();
       //刷新myListView
       myListView.invalidateViews();
       myEditText.setText("");
       _id =0;
    }
   
   
    private void editTodo(){
    if(myEditText.getText().toString().equals(""))
    return ;
       //修改数据
    myToDoDB.update(_id, myEditText.getText().toString());
    myCurson.requery();
    myListView.invalidateViews();
    myEditText.setText("");
    _id=0;
   
    }
   
    private void deleteTodo(){
    if(_id==0){
    return;
    }
    //删除数据
    myToDoDB.delete(_id);
    myCurson.requery();
    myListView.invalidateViews();
    myEditText.setText("");
    _id=0;
    }
   
}
   ToDoDB.java

  package com.chaowen;

[code="java"]import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

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

  @Override
  public void onCreate(SQLiteDatabase db)
  {
    /* ミtable */
    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 long insert(String text)
  {
    SQLiteDatabase db = this.getWritableDatabase();
    /* 盢穝糤ContentValues */
    ContentValues cv = new ContentValues();
    cv.put(FIELD_TEXT, text);
    long row = db.insert(TABLE_NAME, null, cv);
    return row;
  }

  public void delete(int id)
  {
    SQLiteDatabase db = this.getWritableDatabase();
    String where = FIELD_id + " = ?";
    String[] whereValue =
    { Integer.toString(id) };
    db.delete(TABLE_NAME, where, whereValue);
  }

  public void update(int id, String text)
  {
    SQLiteDatabase db = this.getWritableDatabase();
    String where = FIELD_id + " = ?";
    String[] whereValue =
    { Integer.toString(id) };
    /* 盢эContentValues */
    ContentValues cv = new ContentValues();
    cv.put(FIELD_TEXT, text);
    db.update(TABLE_NAME, cv, where, whereValue);
 

 

评论

1 楼 wangkai1018 2011-07-08  

多谢楼主分享！ 楼主的头像内容 很是给力，支持你