Android read SD card capacity

In the development, we often use the SD card, then when the SD card read and write, we often need to determine whether the remaining capacity of the SD card is sufficient. So this time we're going to write a program that gets the SD card capacity.

The attention of the place, I have in the program has been noted. See the program basically understand ha.

Let's take a look at the results of the operation.

Layout file Activity_main.xml

<LinearLayoutxmlns:android= "Http://schemas.android.com/apk/res/android"Xmlns:tools= "Http://schemas.android.com/tools"Android:layout_width= "Match_parent"Android:layout_height= "Match_parent"android:orientation= "vertical"Android:paddingbottom= "@dimen/activity_vertical_margin"Android:paddingleft= "@dimen/activity_horizontal_margin"Android:paddingright= "@dimen/activity_horizontal_margin"Android:paddingtop= "@dimen/activity_vertical_margin"Tools:context= "Com.example.sdcard.MainActivity" >    <TextViewAndroid:id= "@+id/tv"Android:layout_width= "Wrap_content"Android:layout_height= "Wrap_content"Android:text= "@string/hello_world" />    <TextViewAndroid:id= "@+id/tv2"Android:layout_width= "Wrap_content"Android:layout_height= "Wrap_content"Android:text= "@string/hello_world" />          <TextViewAndroid:id= "@+id/tv3"Android:layout_width= "Wrap_content"Android:layout_height= "Wrap_content"Android:text= "@string/hello_world" /></LinearLayout>

Java file Mainactivty.java

 PackageCom.example.sdcard;ImportJava.io.File;ImportAndroid.annotation.SuppressLint;Importandroid.app.Activity;ImportAndroid.os.Build;ImportAndroid.os.Bundle;Importandroid.os.Environment;ImportAndroid.os.StatFs;ImportAndroid.text.format.Formatter;ImportAndroid.widget.TextView;Importandroid.widget.Toast; @SuppressLint ("Showtoast") Public classMainactivtyextendsActivity {@SuppressWarnings ("Deprecation") @SuppressLint ("Newapi") @Overrideprotected voidonCreate (Bundle savedinstancestate) {//TODO auto-generated Method Stub        Super. OnCreate (savedinstancestate);        Setcontentview (R.layout.activity_main); TextView TV=(TextView) Findviewbyid (r.id.tv); TextView TV2=(TextView) Findviewbyid (R.ID.TV2); TextView TV3=(TextView) Findviewbyid (R.ID.TV3); LongblockSize; Longtotalblocks; Longavaibleblocks; //determine if a memory card is plugged in and mounted        if(Environment.getexternalstoragestate (). Equals (environment.media_mounted)) {File path =environment.getexternalstoragedirectory (); StatFs StatFs=NewStatFs (Path.getpath ()); /** Build.VERSION.SDK_INT: Gets the current system version level * Build.version_codes. JELLY_BEAN_MR2 that Android 4.3, that is 18, here directly write 18 can also * because Getblocksizelong () and other three methods are only after the Android 4.3, so it is necessary to determine the current system version * Supplement One             A knowledge point: All storage devices are divided into blocks, each with a fixed size. */            if(Build.VERSION.SDK_INT >=Build.version_codes. JELLY_BEAN_MR2) {//get the number of blocksBlockSize =Statfs.getblocksizelong (); //get a total of how many blocksTotalblocks =Statfs.getblockcountlong (); //blocks that can be activeAvaibleblocks =Statfs.getavailableblockslong (); Tv.settext ("Total space:" + formatsize (totalblocks *blockSize)); Tv2.settext ("Free space:" + formatsize (avaibleblocks *blockSize)); Tv3.settext ("Used space:" + formatsize (totalblocks *blockSize)-(Avaibleblocks *( blockSize))); } Else {                /** The black line indicates that the three APIs are obsolete. But in order to be compatible with 4.3 systems, we need to write*/blockSize=statfs.getblocksize (); Totalblocks=Statfs.getblockcount (); Avaibleblocks=statfs.getavailableblocks (); Tv.settext (Formatsize (avaibleblocks*blockSize)); }        } Else{Toast.maketext ( This, "SD card not found", 0); }    }    PrivateString Formatsize (Longsize) {        //formats the displayed data.         returnFormatter.formatfilesize (mainactivty. This, size); }}

Android read SD card capacity