android建立數據庫(SQLite)保存圖片示例

//1.建立數據庫

public class DBService extends SQLiteOpenHelper {  

 private final static int VERSION = 1;

private final static String DATABASE_NAME = "uniteqlauncher.db"; 

 public DBService(Context context) {

    this(context, DATABASE_NAME, null, VERSION);

} 

 public DBService(Context context, String name, CursorFactory factory,

        int version) {

    super(context, name, factory, version);

} 

 @Override

public void onCreate(SQLiteDatabase db) {

    String sql = "CREATE TABLE [launcher]("

        + "[_id] INTEGER PRIMARY KEY AUTOINCREMENT,"

        + "[photo] BINARY)"; //保存爲binary格式 

     db.execSQL(sql); 

 } 

 @Override

public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    if(newVersion > oldVersion){

        db.execSQL("DROP TABLE IF EXISTS[launcher]");

    } else {

        return;

    }

    onCreate(db);

}

}

//保存圖片到數據庫

public void savePhoto(Drawable appIcon, Context mContext){

LayoutInflater mInflater = (LayoutInflater) mContext

.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

View v = inflater.inflate(R.layout.app_view, null);

ImageView iv = (ImageView) v.findViewById(R.id.appicon);

iv.setImageDrawable(appIcon);

String INSERT_SQL = "INSERT INTO launcher(photo) values(?)";

SQLiteDatabase db = mDBService.getWritableDatabase(); // 獲得數據庫

try {

ByteArrayOutputStream baos = new ByteArrayOutputStream();

((BitmapDrawable) iv.getDrawable()).getBitmap().compress(

CompressFormat.PNG, 100, baos);//壓縮爲PNG格式,100表示跟原圖大小同樣

Object[] args = new Object[] {baos.toByteArray() };

db.execSQL(INSERT_SQL, args);

baos.close();

db.close();

} catch (Exception e) {

e.printStackTrace();

} 

 } 

 //3.從數據庫中取圖片

public void getPhoto() {

String SELECT_SQL = "SELECT photo FROM launcher";

ImageView appIcon = (ImageView) v.findViewById(R.id.appicon);//v是我在類中定義的一個view對象，跟前面保存圖片同樣

byte[] photo = null;

mDBService = new DBService(getContext());

SQLiteDatabase db = mDBService.getReadableDatabase();

Cursor mCursor = db.rawQuery(SELECT_SQL, null);

if (mCursor != null) {

if (mCursor.moveToFirst()) {//just need to query one time

photo = mCursor.getBlob(mCursor.getColumnIndex("photo"));//取出圖片

}

}

if (mCursor != null) {

mCursor.close();

}

db.close();

    ByteArrayInputStream bais = null;

if (photo != null) {

        bais = new ByteArrayInputStream(photo);

        appIcon.setImageDrawable(Drawable.createFromStream(bais, "photo"));//把圖片設置到ImageView對象中

} 

    //appIcon顯示的就是以前保存到數據庫中的圖片

}