external sd card reader for android

each time through the output stream to the SD card to write files, connected to the computer, using MTP to simulate a mobile disk, open the disk but there is no such a file, and the way to see through the ADB, the cause of this phenomenon is that after each write, the MTP database is not updated, Because the update of the MTP database requires a large price ratio, so only in the restart, mount and the user

each time through the output stream to the SD card to write files, connected to the computer, using MTP to simulate a mobile disk, open the disk but there is no such a file, and the way to see through the ADB, the cause of this phenomenon is that after each write, the MTP database is not updated, Because the update of the MTP database requires a large price ratio, so only in the restart, mount and the user

Each time through the output stream to the SD card to write files, connected to the computer, using MTP to simulate a mobile disk, open the disk but there is no such a file, and the way to see through the ADB, the cause of this phenomenon is that after each write, the MTP database is not updated, Because the update of the MTP database requires a large price ratio, so only in the restart, mount and the user

= Environment.getexternalstoragestate ();if (State.equals (environment.media_mounted)) {File root = Environment.getexternalstoragedirectory ();File TargetDir = new file (Root,super.getpackagename ());if (! Targetdir.exists ()) {Targetdir.mkdir ();}try {Oos = new ObjectOutputStream (new FileOutputStream (New File (TargetDir, "yxl.txt"));Student Student = new Student ("Xiaoming", 18);Oos.writeobject (student);Toast.maketext (Getapplication (), "Write succeeded", Toast.length_short). Show ();} cat

When we do Android development, we often have this experience, because the customer's device models are different, resulting in a variety of problems, but for developers, because there is no log log files, it is not easy to locate the exact location of the problem. So we need a tool that can write the program log to the SD card file, like the Web log4j. At this t

] = = '. ') | |(Name_len = = 2 de_src->d_name[0] = = '. ' de_src->d_name[1] = = '. ')) {Continue}else {src dir path Append the folder ' s D_namesprintf (Src_file_path, "%s/%s", Src_dir_path, De_src->d_name);printf ("src dir path:%s\n", Src_file_path);Des dir path Append the folder ' s D_namesprintf (Des_file_path, "%s/%s", Des_dir_path, De_src->d_name);printf ("Des dir path:%s\n", Des_file_path);printf ("---entry sub dir to restore\n");ret = Restore_dir_file (Des_file_path, Src_file_path);prin

1. Save to SD card:Get the status of SDcard:Environment.getextemalstoragestate ()Environment.media_mounted mobile phone is equipped with sdcard and can read and writeGet the directory of SDcard: Environment.getextemalstoragedirectory ()//=============================================File Savefile=new file ("/sdcard/zhzhg.txt");Or: File Sdcarddir=new file ("/sdcard");//get SD

The first few days encountered a problem: Save the image to the SD card in the Android development app, and the user searched in the gallery, similar to the form of the cache. The first idea is to change the suffix name, for example, to save a picture as Image1.txt, so save of course no problem, but in the application of reading in the not, and later did not stud

Add a file directly to the SD card of the simulator in ddms. If an error occurs, the following error occurs:Failed to push xxxxx.txt on emulator-: Read-Only file system error, because your sdcard permission is insufficient and you need to create an sdcard directly. I. First create an sdcard. The name of the sdcard I created is sdcard. IMG (the name is random and ends with the name of the IMG extension)

The first step is to increase the access rights of the SD card in Androidmanifest.xmldoes the SD card existPrivate Boolean Existsdcard () { if (android.os.Environment.getExternalStorageState (). Equals ( Android.os.Environment.MEDIA_MOUNTED) { return true; } else return false; }

= "error") {toast. maketext (mainactivity. this, "reading failed! ", Toast. length_short). Show (); show. settext (" reading failed! "); Return;} Show. settext (" read successful: "+ Str); toast. maketext (mainactivity. This," read successful! ", Toast. length_short ). show () ;}}); write. setonclicklistener (New onclicklistener () {public void onclick (view v) {string STR = show. gettext (). tostring (); If (writesdcard (STR) = true) {toast. maketext (mainactivity. this, "Write successful! ",

/*** Method of obtaining SD information*/ Private voidGetsd () {//TODO auto-generated Method StubFile path=environment.getexternalstoragedirectory (); StatFs Stat=NewStatFs (Path.getpath ()); LongBlocksize=stat.getblocksize (); Longtotalblacks=Stat.getblockcount (); Longavailableblocks=stat.getavailableblocks (); Longtotalsize=blocksize*totalblacks; Longavailsize=availableblocks*blockSize; String Totalstr=formatter.formatfilesize (mainactivity. Thi

Directly on the code:Package Com.example.callstatus;import Java.io.file;import Java.io.filewriter;import java.io.ioexception;import Java.io.printwriter;import Java.io.stringwriter;import Java.net.unknownhostexception;import Java.text.simpledateformat;import Java.util.date;import Android.annotation.suppresslint;import Android.os.environment;import android.util.log;/** * Android Development Debug Log Tool class [support save to

Android newest mobile phone internal storage size, SD card storage size Method We used to obtain this information in the past. // Before Android API18: fs. getAvailableBlocks () * fs. getBlockSize () Currently: /** Obtain available system memory **/@ SuppressLint ("NewApi") private String getMemFree () {S

1. Get the directory of the storage device:/sdcard (generally) Sdpath = environment. getexternalstoragedirectory () + "/";2. Determine whether the folder on the SD card exists: Use the exists () method of the file object./*** Determine whether a file already exists;*/Public Boolean checkfileexists (string filepath ){File file = new file (sdpath + filepath );Return file. exists ();}3. Create a directory on t