Android sd卡读取数据库实例代码

Android sd卡读取数据库实例代码

前言：

本文主要给大家讲解如何利用Android SD卡读取数据库，提供一些代码如下。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; 
  } 

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