本文实例讲述了android编程实现sd卡读取数据库的方法。分享给大家供大家参考,具体如下:
先在 Manifest 里添加权限:
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< uses-permission android:name = "android.permission.WRITE_EXTERNAL_STORAGE" /> < uses-permission android:name = "android.permission.MOUNT_UNMOUNT_FILESYSTEMS" /> |
然后在 mainActivity 添加方法:
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SQLiteDatabase db; private final String DATABASE_PATH = android.os.Environment .getExternalStorageDirectory().getAbsolutePath() + "/vote" ; private String DATABASE_FILENAME = "db_vote.db" ; // 初始化数据库 private SQLiteDatabase openDatabase() { try { String databaseFilename = DATABASE_PATH + "/" + DATABASE_FILENAME; File dir = new File(DATABASE_PATH); if (!dir.exists()) dir.mkdir(); if (!( new File(databaseFilename)).exists()) { InputStream is = getResources().openRawResource(R.raw.db_vote); FileOutputStream fos = new FileOutputStream(databaseFilename); byte [] buffer = new byte [ 8192 ]; int count = 0 ; while ((count = is.read(buffer)) > 0 ) { fos.write(buffer, 0 , count); } fos.close(); is.close(); } db = SQLiteDatabase.openOrCreateDatabase(databaseFilename, null ); return db; } catch (Exception e) { e.printStackTrace(); } return null ; } |
希望本文所述对大家Android程序设计有所帮助。