android编程实现sd卡读取数据库的方法

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：

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;
}

希望本文所述对大家Android程序设计有所帮助。