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;

    }