android sd卡读取数据库

先在 Manifest 里添加权限

<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

    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;    }

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