Android app small instance-SD card file browser

 

Finally:

 

Implement the SD card file browser

Technical analysis:

The main controls used:Listview

How to fill in the listview control, you need to traverse all the files under the entire SD card. If you traverse a folder, first obtain all the files under the folder, then we can fill all the files in this listview, so we can repeat it.

How can I get the modification date of a folder or file?

The file class in Java only provides us with a public long lastmodified (): The long value of the last modification time of the file. It is used with the time point (January 1, January 1, 1970, 00:00:00 GMT) in milliseconds. If the file does not exist or an I/O error occurs, 0l is returned.

File myfile = new file ("d :\\ common android development icons"); long modtime = myfile. lastmodified (); simpledateformat dateformat = new simpledateformat ("yyyy-mm-dd hh: mm: SS"); system. out. println (dateformat. format (new date (modtime )));

 

Implementation Code:

 

 

Package COM. jiahui. sdcardfileexplorer; import Java. io. file; import Java. text. dateformat; import Java. text. simpledateformat; import Java. util. arraylist; import Java. util. date; import Java. util. hashmap; import Java. util. list; import Java. util. map; import android. app. activity; import android. OS. bundle; import android. view. view; import android. widget. adapterview; import android. widget. adapterview. onitemclicklistene R; import android. widget. button; import android. widget. listview; import android. widget. simpleadapter; import android. widget. textview; import android. widget. toast; public class sdcardfileexploreractivity extends activity {private textview tvpath; private listview lvfiles; private button btnparent; // record the current parent folder file currentparent; // record the file array file [] currentfiles; Public void oncreate (bundle savedinstan Cestate) {super. oncreate (savedinstancestate); setcontentview (R. layout. main); lvfiles = (listview) This. findviewbyid (R. id. files); tvpath = (textview) This. findviewbyid (R. id. tvpath); btnparent = (button) This. findviewbyid (R. id. btnparent); // obtain the system's sdcard directory file root = new file ("/mnt/sdcard/"); // If the SD card exists (root. exists () {currentparent = root; currentfiles = root. listfiles (); // use all files and folders in the current directory to fill in listvie Winflatelistview (currentfiles);} lvfiles. setonitemclicklistener (New onitemclicklistener () {@ overridepublic void onitemclick (adapterview <?> Adapterview, view, int position, long ID) {// if the user clicks a file, return directly without any processing if (currentfiles [position]. isfile () {// You can also customize the extension to open this file and other return;} // obtain all the files in the folder clicked by the user [] TEM = currentfiles [position]. listfiles (); If (TEM = NULL | TEM. length = 0) {toast. maketext (sdcardfileexploreractivity. this, "the current path is not accessible or there are no files under this path", toast. length_long ). show ();} else {// get the folder corresponding to the list item clicked by the user, set as the current parent folder currentparent = currentfiles [Position]; // save all files and folders in the current parent folder currentfiles = TEM; // update listviewinflatelistview (currentfiles) again );}}}); // obtain the btnparent of the upper-level directory. setonclicklistener (new view. onclicklistener () {@ overridepublic void onclick (view v) {try {If (! Currentparent. getCanonicalPath (). equals ("/mnt/sdcard") {// obtain the currentparent = currentparent. getparentfile (); // list all files in the current directory currentfiles = currentparent. listfiles (); // update listviewinflatelistview (currentfiles) again;} catch (exception e) {// todo: handle exception }}});} /*** fill listview ** @ Param files */private void inflatelistview (file [] files) {list <Map <string, object> listitems = new arraylist <Map <string, Object> (); For (INT I = 0; I <files. length; I ++) {Map <string, Object> listitem = new hashmap <string, Object> (); If (files [I]. isdirectory () {// if it is a folder, the picture displayed is the folder image listitem. put ("icon", R. drawable. folder);} else {listitem. put ("icon", R. drawable. file);} // Add a file name listitem. put ("FILENAME", files [I]. getname (); file myfile = new file (files [I]. getname (); // get the last modification date of the object long modtime = myfile. lastmodified (); simpledateformat dateformat = new simpledateformat ("yyyy-mm-dd hh: mm: SS"); system. out. println (dateformat. format (new date (modtime); // Add a Last modified Date listitem. put ("modify", "modification date:" + dateformat. format (new date (modtime); listitems. add (listitem);} // defines a simpleadaptersimpleadapter adapter = new simpleadapter (sdcardfileexploreractivity. this, listitems, R. layout. list_item, new string [] {"FILENAME", "icon", "modify"}, new int [] {R. id. file_name, R. id. icon, R. id. file_modify}); // fill in the dataset lvfiles. setadapter (adapter); try {tvpath. settext ("current path:" + currentparent. getCanonicalPath ();} catch (exception e) {e. printstacktrace ();}}}

 

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Source code download: http://download.csdn.net/download/jiahui524/3800378