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public SQLiteDatabase getDatabase(String dbfile) {
if(databases.get(dbfile) != null){
Log.i(tag, String.format("Return a database copy of %s", dbfile));
return (SQLiteDatabase) databases.get(dbfile);
}
if(context==null)
return null;
Log.i(tag, String.format("Create database %s", dbfile));
String spath = getDatabaseFilepath();
String sfile = getDatabaseFile(dbfile);
File file = new File(context.getFilesDir(), sfile);
File file1 = new File(spath);
if(file1.mkdirs())
Log.i("mkdir","success");
if(file.exists())
Log.i("db", "数据库文件找到了");
SharedPreferences dbs = context.getSharedPreferences(AssetsDatabaseManager.class.toString(), 0);
boolean flag = dbs.getBoolean(dbfile, false); // Get Database file flag, if true means this database file was copied and valid
if(!flag || !file.exists()){
file = new File(context.getFilesDir(),spath);
if(!file.exists() && !file.mkdirs()){
Log.i(tag, "Create \""+spath+"\" fail!");
return null;
}
if(!copyAssetsToFilesystem(dbfile, context.getFilesDir()+sfile)){
Log.i(tag, String.format("Copy %s to %s fail!", dbfile, sfile));
return null;
}
dbs.edit().putBoolean(dbfile, true).commit();
}
SQLiteDatabase db = SQLiteDatabase.openDatabase(context.getFilesDir()+sfile, null, SQLiteDatabase.NO_LOCALIZED_COLLATORS);
if(db != null){
databases.put(dbfile, db);
}
return db;
}
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="cn.zzh.testmenu"
android:versionCode="1"
android:versionName="1.0">
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".YearLineActivity">
<intent-filter>
<action android:name="android.intent.action.YEARLINE"/>
<category android:name="android.intent.category.DEFAULT"/>
</intent-filter>
</activity>
</application>
</manifest>
public class PermisionUtils {
// Storage Permissions
private static final int REQUEST_EXTERNAL_STORAGE = 1;
private static String[] PERMISSIONS_STORAGE = {
Manifest.permission.READ_EXTERNAL_STORAGE,
Manifest.permission.WRITE_EXTERNAL_STORAGE};
/**
* Checks if the app has permission to write to device storage
* If the app does not has permission then the user will be prompted to
* grant permissions
*
* @param activity
*/
public static void verifyStoragePermissions(Activity activity) {
// Check if we have write permission
int permission = ActivityCompat.checkSelfPermission(activity,
Manifest.permission.WRITE_EXTERNAL_STORAGE);
if (permission != PackageManager.PERMISSION_GRANTED) {
// We don't have permission so prompt the user
ActivityCompat.requestPermissions(activity, PERMISSIONS_STORAGE,
REQUEST_EXTERNAL_STORAGE);
}
}
}
我用的是这种动态加入