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:
<uses-permissionandroid:name="android.permission.WRITE_EXTERNAL_STORAGE"/> <uses-permissionandroid:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
然后在mainActivity添加方法:
SQLiteDatabasedb; privatefinalStringDATABASE_PATH=android.os.Environment .getExternalStorageDirectory().getAbsolutePath()+"/vote"; privateStringDATABASE_FILENAME="db_vote.db"; //初始化数据库 privateSQLiteDatabaseopenDatabase(){ try{ StringdatabaseFilename=DATABASE_PATH+"/"+DATABASE_FILENAME; Filedir=newFile(DATABASE_PATH); if(!dir.exists()) dir.mkdir(); if(!(newFile(databaseFilename)).exists()){ InputStreamis=getResources().openRawResource(R.raw.db_vote); FileOutputStreamfos=newFileOutputStream(databaseFilename); byte[]buffer=newbyte[8192]; intcount=0; while((count=is.read(buffer))>0){ fos.write(buffer,0,count); } fos.close(); is.close(); } db=SQLiteDatabase.openOrCreateDatabase(databaseFilename,null); returndb; }catch(Exceptione){ e.printStackTrace(); } returnnull; }
希望本文所述对大家Android程序设计有所帮助。