I recently studied Android and found many bugs in the latest version 4.0.3. I am sorry that the "Google input method has stopped running" camera device has stopped running and so on, so I switched to 2.2 for learning! Occasionally, you need to drop the file into the SD card for an instance during learning. The following figures can be used to complete this operat
Need to quickly extract pictures and video thumbnails to directly access Android.provider.MediaStore.Images.Thumbnails And android.provider.MediaStore.Video.Thumbnails These two databases, you can query the thumbnail.
How do you judge a document? You can traverse the database by cursor, comparing the value of the Internal_content_uri field, which is a URI that holds the full path to the multimedia file on the Android phone's
Package Com.wenhao.test.sddemo;import Java.io.file;import android.app.activity;import android.os.Bundle;import Android.os.environment;import Android.view.view;import Android.view.view.onclicklistener;import Android.widget.button;import Android.widget.Toast; Public classMaindemo extends Activity {/** Called when the activity is first created.*/ PrivateButton Button =NULL; PrivateFile Path; @Override Public voidonCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate);
This example for you to share the simplest SD card file traversal procedures for your reference, the specific content as follows
Package Com.wenhao.test.sddemo;
Import Java.io.File;
Import android.app.Activity;
Import Android.os.Bundle;
Import android.os.Environment;
Import Android.view.View;
Import Android.view.View.OnClickListener;
Import Android.widget.Button;
Import Android.widget.Toast; The pu
The following is a tool class. It uses recursion to scan the APK file on the SD card to determine whether the application has been installed on the mobile phone. If so, it determines whether the application can be upgraded. DetailsCodeAs follows:
/*** Obtain the APK File Information class on the mobile phone, mainly to determine whether or not to install it on the mobile phone, the installed version
[] buffer =New byte[1*1024];//Stream Read IndexintDownloadnum = 0; //writes an input stream to a file while((Downloadnum = inputstream.read (buffer))! =-1) {output.write (buffer,0, downloadnum);} Output.flush ();When the file is downloaded to the SD card, output.write (buffer); This code is absolutely problematic and causes the file to become corrupted. So take care of it.Because assuming that you read 40kb
If you use Google's own simulator or the real machine debugging, the SD card directory is/mnt/sdcard. This is a belief that we all know.but today with Genymotion debugging, found at all not open/mnt/sdcard This directory, at that time also did not pay attention to other information, think is adb, eclipse what problem, After restarting them still can't open, after a struggle, found an important clue! Oh, it
If you want to use SD card during development, you must specify
There are two ways to create an SD card. One is to directly enter the size to be created and the ADT is automatically created. The other is the image file of the specified sdcard.
Use the mksdcard.exe tool in sdkto create an image file for sdcard. For
Read the SD card file information and add it to the listview to display it:
Listview obtains the information of the SD FileCode:
List
Draw different images based on filetype:
Public long getsdtotalsize () {/* Gets the memory card path */File sdcarddir= environment.getexternalstoragedirectory (); /*statfs See File system space Usage */StatFs statfs=new StatFs (Sdcarddir.getpath ()); Long blocksize= Statfs.getblocksizelong (); Long Totalsize=statfs.getblockcountlong (); return blocksize*totalsize;} /** * Get the remaining capacity of SD
.
Propertyconfigurator. getconfigurator (this). Configure ();
4. Put the microlog. properties file in the assets folder.
Note: The assets folder is the same as the res folder.
Then change the microlog. properties file to the following:
Microlog. Level = debugMicrolog. appender = logcatappender; fileappenderMicrolog. formatter = patternformatterMicrolog. formatter. patternformatter. pattern = % C [% P] % m % t
5. Write log records
Logger. debug ("My debug ");
6. Add
The specific usage is as follows:
1. Download
Download the http://code.google.com/p/microlog4android/downloads/list and microlog. properties files to the microlog4android-1.0.0.jar
2. Create a logger object
Private Static final logger = loggerfactory. getlogger (main. Class );
3.ProgramThe initialization method in the oncreate method of the first activity
Propertyconfigurator. getconfigurator (this). Configure ();
4. Put the microlog. properties file in the assets folder.
Note: Th
Objective:Use the activity of the Openfileoutput () method to save the file, the file is stored in the mobile phone space, the general phone storage space is not very large, storage of small files is OK, if you want to store large files such as video, it is not feasible. For large files like video, we can store it in SDcard. What is sdcard for? You can think of it as a removable hard drive or USB stick.To use SDcard in the simulator, you need to first create a SDcard
The Android system can get the path of the memory card through Environment.getexternalstoragedirectory (), but now there are a lot of phones built in a storage space, but also support the external SD card insertion, This through the Environment.getexternalstoragedirectory ()
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