Android Common function code block

1, set activity Untitled, Full screen

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2. Get screen height and width

// Gets the height and width of the screen used to windowmanager this class WindowManager wm =int width = wm.getdefaultdisplay (). getwidth (); int height = wm.getdefaultdisplay (). GetHeight ();

3. Get all kinds of information about mobile phone

Telephonymanager TM = (Telephonymanager) This. Getsystemservice (Context.telephony_service); String IMEI= Tm.getdeviceid ();//Mobile Device International identification codeString IMSI = Tm.getsubscriberid ();//International Mobile Subscriber Identification CodeString Tel = tm.getline1number ();//Phone numberString Model= Android.os.Build.MODEL;//Phone ModelString SDK = Android.os.Build.VERSION.SDK;//SDK versionString release = Android.os.Build.VERSION.RELEASE;//System Version//identify mobile providers based on IMSI numbers Publicstring Getprovidersname (String IMSI) {string Providersname=NULL; //IMSI Front 3 bit 460 is the country, followed by 2 bit 00 02 is China Mobile, 01 is China Unicom, 03 is Chinese telecom.     if(Imsi.startswith ("46000") | | Imsi.startswith ("46002") ) {Providersname= "China Mobile"; } Else if(Imsi.startswith ("46001") ) {Providersname= "China Unicom"; } Else if(Imsi.startswith ("46003") ) {Providersname= "China Telecom"; }    returnProvidersname;}

4. Use Toast to output a string

 Public void showtoast (String text) {    Toast.maketext (this, Text, Toast.length_short). Show ();

5. Write a string into the file

//write a string into the file Public voidWriteFile (String str,string path) {file file;    FileOutputStream out; Try{        //Create a fileFile =NewFile (path);        File.createnewfile (); //Open File output streamout =Newfileoutputstream (file); //converts a string into a byte array to write to a fileOut.write (Str.getbytes ());    Out.close (); }Catch(IOException e) {}}

6. Read the contents of the file to a string

//read the contents of the file to a string Publicstring GetFileInfo (string path) {file file; String Str= "";    FileInputStream in; Try{        //Open the file InputStreamFileNewFile (path); Inch=Newfileinputstream (file); //reads the contents of a file into a byte array        intLength = (int) file.length (); byte[] temp =New byte[length]; In.read (temp,0, length); STR= encodingutils.getstring (temp, "utf-8"));    In.close (); }Catch(IOException e) {}returnstr;}

7, program installation, uninstall, update

//bring up the system installation applicationString fileName = environment.getexternalstoragedirectory () +Apkname; Uri URI= Uri.fromfile (NewFile (FileName)); Intent Intent=NewIntent (Intent.action_view); Intent.setdataandtype (URI,"Application/vnd.android.package-archive"); This. StartActivity (intent);//bring up the system uninstall appUri Packageuri = Uri.parse ("Package:your.app.id"); Intent Intent=NewIntent (intent.action_delete,Packageuri); startactivity (Intent);

8, realize click two times return key exit

//The first step is to define a variable that identifies whether to exitBooleanIsexit;//Step Two, rewrite the onkeydown method in activity@Override Public BooleanOnKeyDown (intKeyCode, KeyEvent event) {    if(KeyCode = =keyevent.keycode_back)        {exit (); return false; } Else {        return Super. OnKeyDown (KeyCode, event); }}//step three, write an exit method Public voidexit () {if(!isexit) {Isexit=true; Toast.maketext (Getapplicationcontext (),"Press one more time to exit the program", Toast.length_short). Show (); Mhandler.sendemptymessagedelayed (0, 2000); } Else{Intent Intent=NewIntent (Intent.action_main);        Intent.addcategory (Intent.category_home);        StartActivity (Intent); System.exit (0); }}//Fourth step, according to the message in the exit () method, write a handlerHandler Mhandler =NewHandler () {@Override Public voidhandlemessage (Message msg) {//TODO auto-generated Method Stub        Super. Handlemessage (msg); Isexit=false; } };