储存图片数据到数据库中

深碍√TFBOYSˉ_ 2022-06-18 07:45 165阅读 0赞

今天突然接到说是把图片储存导数据库去,在网上找了半天,看到了这个,希望大家有所帮助  
1.创建数据库  
public class HongYeDB extends SQLiteOpenHelper \{  
private final static int VERSION = 1;  
private final static String DATABASE\_NAME = “hongye.db”;

public HongYeDB(Context context) \{  
this(context, DATABASE\_NAME, null, VERSION);  
\}

public HongYeDB(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);  
\}  
\}  
2.保存图片到数据库  
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(); // 得到数据库对象  
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