Android-create a database to the SD cardSQLite comes with SQLiteOpenHelper, while SQLiteOpenHelper stores the database to/data/package name/databasas, in this case, the SQLite database cannot be seen on a mobile phone without a root user. So, in another way, store the database SQLite on the SD card. The getWritableDatabase method is associated with this method. I
When you get an SD card, you need to format, partition, modify parameters in the Linux environment, please look over.Ubuntu Virtual Machine Environment1, insert, force point, because there may be poor contact, causing the computer is not recognized.2,cat/proc/partions or fdisk-l (some may need to go to get administrator privileges, deei~ command before +sudo on line)For example: cat/proc/partitionsMajor Min
Because of the large amount of data that needs to be recorded, and sometimes the user is inconvenient to upload data in real time, it is required to use SD card to store data and then manually collect uploads. For this we have chosen a Universal SD card reader and writer.1 , Card
The previous section describes how to store files to internal devices. Sometimes, you need to store files to external storage devices, such as SD cards. Because the SD card has a larger storage space and can easily share these files with other users.
Use the example in the previous section to save the text you entered on the
1. mksdcard command
Run cmd to enter the SDK tools directory and run the mksdcard command. The following help information is displayed:
We can see that sdcard image supports the FAT32 format. Usage: mksdcard [-l label]
-L the disk is followed by the volume label. For example, G indicates g disk;Size indicates the size, measured in KB and MB;File indicates the generated SD image file name, such as android_sdcard_image.
2. Simulate
If using the default system management, the default is placed under the package, more worry, and after uninstalling the app will not cause data residue, but this also has a problem, such as I do a back word software, then when the user uninstalled the app, he worked hard to download the word library also lost ...So I think of the solution is to change the database path, not put under the package, put on the SD car
The SD card contains four types:
SDSC: Standard capacity Card, sd1.1/1.0 specification, capacity 1MB-2GB, file format FAT32
SDHC: High capacity SD card, SD2.0 specification, capacity 4g-32g, file format is FAT32
SDXC: Capacity-enlarged secure memory
An easy way for Android to determine the presence and capacity of an SD card is as follows:The first step is to increase the access rights of the SD card in Androidmanifest.xml[HTML]View Plaincopy
uses-permission android:name="Android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
uses-permission andr
Reprint Please specify source: http://blog.csdn.net/l1028386804/article/details/47375595At present, many Android phone software in the market has the function of clearing SD card cache, such as 360, Jinshan and so on. So how does the software implement the ability to clean up the SD card cache data? Below, I will show
Mounted SD card for Android simulator in Linux
1. Create an SD card:
~ /Gingerbread $ mksdcard-l mysdcard 256 m mysdcard. img
Create an SD card image file in the current directory named mysdcard. IMG. 256 MB indicates that the
Test procedure]1. Download an application and open the application;2. Press menu to open the management applicationProgramGo to the SD card and click "application" to view the data moved to the SD card and to the mobile phone memory.Expected results]1. The data transferred to the S
U disk or SD card can also be like a hard disk partition, the following tells you how to identify a U disk (SD card) in Windows under the multiple partitions. can also be a U-disk (SD card) under Windows, want to divide how much.
BBB power on by pressing the button can decide to boot from the SD card, if there is a system from the SD card boot, if not on the boot from the eMMC. Because the BBB has already had the 4G eMMC, inside the factory existence Angstrom Linux, this system is specially for the embedded Linux system, therefore for the gener
The previous section describes how to store files to an internal device. Sometimes, you need to store files to an external storage device, such as an SD card. Because SD cards have greater storage space, they can also be easily shared with other users.
Use the example in the previous section to save the text entered by the user on the
Android 2.2 software can be installed on SD for support, ADB commands have also been improved, for Android 2.2 firmware PM command support installation option parameters, the setinstalllocation parameter is added here. Here we can use ADB to execute the Linux PM command to add some parameters, such as ADB shell PM setinstalllocation 0. The last parameter 0 indicates auto. The Android system automatically selects this parameter, while 1 indicates the R
SD card mounting file system: VFS: Cannotopenrootdevice quot; mmcblk0p2 quot; solve the problem of using the initramfs file system. linux can run normally and read and write SD cards normally. However, if it is mounted to the SD card, the disk cannot be mounted. the bootar
android.util.log;/** * is used to support access to the database stored on the SD card **/public class Databasecontext extends Contextwrapper { /** * Constructor * @param base context */public databasecontext (context base) {Su Per (base); /** * Get the database path, if not present, create object Object * @param name * @param mode * @param FA Ctory */@Override public File
/**************************************************************************** * I.MX6 uSDHC SD card reg Ister * Statement: * This article is mainly to record the SD card registration related processes and some problems encountered. * 2015-12-20 Shenzhen Nanshan Ping Shan village Zengjianfeng ***************************
can store more data.
2. Store database files in the SD card!
What is sqlitedatabase?
An instance of sqlitedatabase represents an SQLite database. Through some methods of the sqlitedatabase instance, we can execute SQL statements to add, delete, query, and modify data databases. Note that the database is private to an application, and the database name is unique in an application.
What is sqliteopenhelpe
When using Android phones, we found that someProgramAllowed to be moved to the SD card, but some cannot? Why?
Because Android 2.2 and later versions are allowed to be moved to the SD card. However, all applications developed earlier do not have this function.
So how can I allow your app to move to the
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