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" />
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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 ;
}
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希望本文所述对大家Android程序设计有所帮助。