Android数据库SD卡创建和图片存取操作

Android数据库中的创建，图片的存、取操作如下：

数据库类：

import android.content.Context; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteOpenHelper; 
import android.util.Log; 
 
 
public class MySQLiteOpenHelper extends SQLiteOpenHelper { 
  public static final String DATAbase_NAME = "text.db"; // 数据库名 
  public static final int VERSION = 1; // 版本号 
  public static final String TABLE_NAME = "text"; // 表名 
  public static final String ID = "id"; 
  public static final String IMAGE = "image"; 
 
  public MySQLiteOpenHelper(Context context) { 
    super(context, DATAbase_NAME, null, VERSION); 
  } 
 
   
  @Override 
  public void onCreate(SQLiteDatabase db) { 
    // 创建数据表的操作 
    String strSQL = "CREATE TABLE " + TABLE_NAME + "(" + ID 
 + " INTEGER PRIMARY KEY AUTOINCREMENT," + IMAGE + " blob not null );"; 
 
    db.execSQL(strSQL); 
  } 
 
   
  @Override 
  public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
    Log.e("AndyDemo", "onUpgrade"); 
  } 
} 

Activity:

private Button btn_newTable, btn_addOne, get_Image; 
private TextView tv; 
private ImageView showimage; 
private MySQLiteOpenHelper myOpenHelper; 
private SQLiteDatabase sqlitedb; 
private File path = new File("sdcard/text"); // 数据库文件目录 
private File f = new File("sdcard/text/text.db"); // 数据库文件 
 
@Override 
public void onCreate(Bundle savedInstanceState) { 
  super.onCreate(savedInstanceState); 
  setContentView(R.layout.main); 
 
  init(); 
 
  // 实例化默认数据库辅助操作对象 
  myOpenHelper = new MySQLiteOpenHelper(this); 
 
  // SD卡中创建数据库文件 
  if (!path.exists()) { // 判断目录是否存在 
    path.mkdirs(); // 创建目录 
  } 
  if (!f.exists()) { // 判断文件是否存在 
    try { 
      f.createNewFile(); // 创建文件 
    } catch (IOException e) { 
      e.printStackTrace(); 
    } 
  } 
} 
 
 
private void init() { 
  tv = (TextView) findViewById(R.id.tv_result); 
  btn_newTable = (Button) findViewById(R.id.newTable); 
  btn_addOne = (Button) findViewById(R.id.addOne); 
  get_Image = (Button) findViewById(R.id.getimage); 
  showimage = (ImageView) findViewById(R.id.showimage); 
  btn_newTable.setonClickListener(new ClickEvent()); 
  btn_addOne.setonClickListener(new ClickEvent()); 
  get_Image.setonClickListener(new ClickEvent()); 
 
} 
 
class ClickEvent implements onClickListener { 
  @Override 
  public void onClick(View v) { 
    try { 
      // SD卡中创建数据库，实例化sqlitedb的操作如下 
      sqlitedb = SQLiteDatabase.openOrCreateDatabase(f, null); 
      if (v == btn_newTable) { // 1.新建数据表 
 String TABLE_NAME = "text"; 
 String ID = "id"; 
 String IMAGE = "image"; 
 String str_sql2 = "CREATE TABLE " + TABLE_NAME + "(" + ID 
     + " INTEGER PRIMARY KEY AUTOINCREMENT," + IMAGE 
     + " blob not null );"; 
 sqlitedb.execSQL(str_sql2); 
 tv.setText("新建数据表成功!"); 
 
      } else if (v == btn_addOne) { // 2.插入一条记录 
 ContentValues values = new ContentValues(); 
 values.put( 
     MySQLiteOpenHelper.IMAGE, 
     drawableChange(getResources().getDrawable( 
  R.drawable.ic_launcher))); 
 sqlitedb.insert(MySQLiteOpenHelper.TABLE_NAME, null, values); 
 tv.setText("添加新数据成功!"); 
      } else if (v == get_Image) { 
 Cursor c = sqlitedb.rawQuery("select * from text", null); 
 c.moveToLast(); 
 
 if (c.isLast()) { 
   byte[] blob = c.getBlob(c 
.getColumnIndex(MySQLiteOpenHelper.IMAGE)); 
   Bitmap bmp = BitmapFactory.decodeByteArray(blob, 0, 
blob.length); 
   showimage.setImageBitmap(bmp); 
 } 
 c.close(); 
      } 
    } catch (Exception e) { 
      tv.setText("操作失败"); 
    } finally { 
      sqlitedb.close(); 
    } 
  } 
} 
 
 
private byte[] drawableChange(Drawable drawable) { 
 
  Bitmap bm = ((BitmapDrawable) drawable).getBitmap(); 
  ByteArrayOutputStream baos = new ByteArrayOutputStream(); 
  bm.compress(Bitmap.CompressFormat.PNG, 100, baos); 
  byte[] date = baos.toByteArray(); 
  return date; 
} 

新建一张表，插入一张图片，效果图如下：

查看表中的数据如下：

取出图片：

OK！！搞定！ 最后别忘了加权限：

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