android创建数据库(SQLite)保存图片示例

android创建数据库(SQLite)保存图片示例

代码如下:

//1.创建数据库

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)"; //保存为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);

}

}

//保存图片到数据库

public void savePhoto(Drawable appIcon, Context mContext){

LayoutInflater mInflater = (LayoutInflater) mContext

.getSystemService(https://www.360docs.net/doc/1a8074781.html,YOUT_INFLATER_SERVICE);

View v = inflater.inflate(https://www.360docs.net/doc/1a8074781.html,yout.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(); // 得到数据库

try {

ByteArrayOutputStream baos = new ByteArrayOutputStream(); ((BitmapDrawable) iv.getDrawable()).getBitmap().compress( CompressFormat.PNG, 100, baos);//压缩为PNG格式,100表示跟原图大小一样

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

db.execSQL(INSERT_SQL, args);

baos.close();

db.close();

} catch (Exception e) {

e.printStackTrace();

}

}

//3.从数据库中取图片

public void getPhoto() {

String SELECT_SQL = "SELECT photo FROM launcher";

ImageView appIcon = (ImageView) v.findViewById(R.id.appicon);//v是我在类中定义的一个view 对象，跟前面保存图片一样

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"));//取出图片

}

}

if (mCursor != null) {

mCursor.close();

}

db.close();

ByteArrayInputStream bais = null;

if (photo != null) {

bais = new ByteArrayInputStream(photo);

appIcon.setImageDrawable(Drawable.createFromStream(bais, "photo"));//把图片设置到ImageView对象中

}

//appIcon显示的就是之前保存到数据库中的图片

}