Common android code

1. Rotating Images
Bitmap bitmapOrg = BitmapFactory. decodeResource (this. getContext (). getResources (), R. drawable. moon );
Matrix matrix = new Matrix ();
Matrix. postRotate (-90); // Rotation Angle
 
Bitmap resizedBitmap = Bitmap. createBitmap (bitmapOrg, 0, 0,
BitmapOrg. getWidth (), bitmapOrg. getHeight (), matrix, true );
BitmapDrawable BMI = new BitmapDrawable (resizedBitmap );

2. Get the mobile phone number
// Create telephone management

TelephonyManager tm = (TelephonyManager)

// Establish a connection with the mobile phone
Activity. getSystemService (Context. TELEPHONY_SERVICE );

// Obtain the mobile phone number

String phoneId = tm. getLine1Number ();

// Remember to add in manifest file
<Uses-permission
Android: name = "android. permission. READ_PHONE_STATE"/>

// The program cannot be implemented on the simulator. You must connect to the mobile phone.

3. format the string in string. xml
// In strings. xml ..
<String name = "my_text"> Thanks for visiting % s. You age is % d! </String>


// And in the java code:
String. format (getString (R. string. my_text), "oschina", 33 );

4. How to set full screen for android
A. Set in java code
/** Full screen settings to hide all decorations in the window */
RequestWindowFeature (Window. FEATURE_NO_TITLE );
GetWindow (). setFlags (WindowManager. LayoutParams. FLAG_FULLSCREEN,
WindowManager. LayoutParams. FLAG_FULLSCREEN); B. configure it in AndroidManifest. xml.
<Activity android: name = ". Login. NetEdit" android: label = "@ string/label_net_Edit"
Android: screenOrientation = "portrait" android: theme = "@ android: style/Theme. Black. NoTitleBar. Fullscreen">
<Intent-filter>
<Action android: name = "android. intent. Net_Edit"/>
<Category android: name = "android. intent. category. DEFAULT"/>
</Intent-filter>
</Activity>

5. Set Activity to Dialog.
Configure theme for Activity nodes in AndroidManifest. xml as follows:

Android: theme = "@ android: style/Theme. Dialog"

6. Check whether the current network is connected.
ConnectivityManager con = (ConnectivityManager) getSystemService (Activity. CONNECTIVITY_SERVICE );
 
Boolean wifi = con. getNetworkInfo (ConnectivityManager. TYPE_WIFI). isConnectedOrConnecting ();

Boolean internet = con. getNetworkInfo (ConnectivityManager. TYPE_MOBILE). isConnectedOrConnecting (); add permissions in AndroidManifest. xml:

<Uses-permission android: name = "android. permission. ACCESS_NETWORK_STATE"/>

7. Check whether an Intent is valid
Public static boolean isIntentAvailable (Context context, String action ){
Final PackageManager packageManager = context. getPackageManager ();
Final Intent intent = new Intent (action );
List <ResolveInfo> list =
PackageManager. queryIntentActivities (intent,
PackageManager. MATCH_DEFAULT_ONLY );
Return list. size ()> 0;
}

8. android dialing
Try {
Intent intent = new Intent (Intent. ACTION_CALL );
Intent. setData (Uri. parse ("tel: + 110 "));
StartActivity (intent );
} Catch (Exception e ){
Log. e ("SampleApp", "Failed to invoke call", e );
}

9. Send Email in android
Intent I = new Intent (Intent. ACTION_SEND );
// I. setType ("text/plain"); // use this line for the simulator
I. setType ("message/rfc822"); // use this line on a real machine
I. putExtra (Intent. EXTRA_EMAIL, new String [] {"test@gmail.com", "test@163.com });
I. putExtra (Intent. EXTRA_SUBJECT, "subject goes here ");
I. putExtra (Intent. EXTRA_TEXT, "body goes here ");
StartActivity (Intent. createChooser (I, "Select email application ."));

10. Open a browser in android
Intent viewIntent = new
Intent ("android. intent. action. VIEW", Uri. parse ("http://vaiyanzi.cnblogs.com "));

StartActivity (viewIntent );

11. android obtains the unique identifier of a device.
String android_id = Secure. getString (getContext (). getContentResolver (), Secure. ANDROID_ID );

12. obtain IP addresses in android
Public String getLocalIpAddress (){
Try {
For (Enumeration <NetworkInterface> en = NetworkInterface. getNetworkInterfaces ();
En. hasMoreElements ();){
NetworkInterface intf = en. nextElement ();
For (Enumeration <InetAddress> enumIpAddr = intf. getInetAddresses ();
EnumIpAddr. hasMoreElements ();){
InetAddress inetAddress = enumIpAddr. nextElement ();
If (! InetAddress. isLoopbackAddress ()){
Return inetAddress. getHostAddress (). toString ();
}
}
}
} Catch (SocketException ex ){
Log. e (LOG_TAG, ex. toString ());
}
Return null;
}

13. android obtains the memory card path and usage
/** Obtain the memory card path */
File sdcardDir = Environment. getExternalStorageDirectory ();
/** StatFs viewing file system space usage */
StatFs statFs = new StatFs (sdcardDir. getPath ());
/** Block size */
Long blockSize = statFs. getBlockSize ();
/** Total number of blocks */
Long totalBlocks = statFs. getBlockCount ();
/** Number of blocks in use */
Long availableBlocks = statFs. getAvailableBlocks ();

14 Add a new contact to android
Private Uri insertContact (Context context, String name, String phone ){

ContentValues values = new ContentValues ();
Values. put (People. NAME, name );
Uri uri = getContentResolver (). insert (People. CONTENT_URI, values );
Uri numberUri = Uri. withAppendedPath (uri, People. Phones. CONTENT_DIRECTORY );
Values. clear ();

Values. put (Contacts. Phones. TYPE, People. Phones. TYPE_MOBILE );
Values. put (People. NUMBER, phone );
GetContentResolver (). insert (numberUri, values );

Return uri;
}

15. View battery usage
Intent intentBatteryUsage = new Intent (Intent. ACTION_POWER_USAGE_SUMMARY );
StartActivity (intentBatteryUsage );

16. Obtain the process number
ActivityManager mActivityManager = (ActivityManager) this. getSystemService (ACTIVITY_SERVICE); List <ActivityManager. RunningAppProcessInfo> mRunningProcess = mActivityManager. getRunningAppProcesses ();

Int I = 1;
For (ActivityManager. RunningAppProcessInfo amProcess: mRunningProcess ){
Log. e ("homer Application", (I ++) + "PID =" + amProcess. pid + "; processName =" + amProcess. processName );
}

17. View battery usage
Intent intentBatteryUsage = new Intent (Intent. ACTION_POWER_USAGE_SUMMARY );
StartActivity (intentBatteryUsage );