android sqlite 图片保存和读出

package com.yiyiweixiao;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;import android.database.sqlite.SQLiteDatabase.CursorFactory;public class MySQLiteOpenHelper extends SQLiteOpenHelper {// 重写构造方法public MySQLiteOpenHelper(Context context, String name,CursorFactory cursor, int version) {super(context, name, cursor, version);}// 创建数据库的方法public void onCreate(SQLiteDatabase db) {// 创建一个数据库，表名：imagetable，字段：_id、image。db.execSQL("CREATE TABLE imagetable (_id INTEGER PRIMARY KEYAUTOINCREMENT,image BLOB)");}// 更新数据库的方法public void onUpgrade(SQLiteDatabase db, int oldVersion, intnewVersion) {}}// 创建助手类的实例// CursorFactory的值为null,表示采用默认的工厂类mySQLiteOpenHelper = new MySQLiteOpenHelper(this, "saveimage.db",null,1);// 创建一个可读写的数据库mydb = mySQLiteOpenHelper.getWritableDatabase();//将图片转化为位图Bitmap bitmap1=BitmapFactory.decodeResource(getResources(),R.drawable.erweima);int size=bitmap1.getWidth()*bitmap1.getHeight()*4;//创建一个字节数组输出流,流的大小为sizeByteArrayOutputStream baos=new ByteArrayOutputStream(size);//设置位图的压缩格式，质量为100%，并放入字节数组输出流中bitmap1.compress(Bitmap.CompressFormat.PNG, 100, baos);//将字节数组输出流转化为字节数组byte[]byte[] imagedata1=baos.toByteArray();//将字节数组保存到数据库中ContentValues cv=new ContentValues();cv.put("_id", 1);cv.put("image", imagedata1);mydb.insert("imagetable", null, cv);//关闭字节数组输出流baos.close();

从数据库中查询的方法：

//创建一个指针Cursor cur=mydb.query("imagetable", new String[]{"_id","image"},null, null, null, null, null);byte[] imagequery=null;if(cur.moveToNext()){//将Blob数据转化为字节数组imagequery=cur.getBlob(cur.getColumnIndex("image"));}//将字节数组转化为位图Bitmap imagebitmap=BitmapFactory.decodeByteArray(imagequery, 0,imagequery.length);iv1=(ImageView) findViewById(R.id.imageView1);//将位图显示为图片iv1.setImageBitmap(imagebitmap);