With out Arguments​

To $broadcast use the $rootScope:

$scope.startCamera = function() { $rootScope.$broadcast('camera-started'); }

To receive, use the $scope of your controller:

$scope.$on('camera-started', function(event, args) { // do something });

With Arguments​

To pass arguments when you $With out Arguments:

$rootScope.$broadcast('camera-started', { any: {} }); To receive arguments :

$scope.$on('camera-started', function(event, args) { var anyArg = args.any;  // do something });

1. To start a new application
   ionic start NagIonic sidemenu

2. Navigate to the project folder NagIonic

3. To Launch an app in browser
   Ionic serve –lab

4. Add platforms
   ionic platform add ios
   ionic platform add android
   ionic platform add windows

5. Add icon and splash
   Place icon.png (192X192 px), splash.png(
   2208×2208 px) in resources folder
   ionic resources

6. To run app on device
   ionic run android

The following code snippets demonstrates the format/template which can be used in Ionic or in Angularjs Applications

/**************************
 * Controller 
 **************************/

(function () {
  'use strict';
  var injectParams = [ /* 'dependency1' */];
 
  function SampleCtrl( /* dependency1 */) {
    var SampleVm = this;
 
    //Bindable Properties and functions
    SampleVm.dummyProperty = '';
    SampleVm.dummyBindableFunc = dummyBindableFunc;
 
    //Functions
    function dummyBindableFunc() { 
    }
 
    function myNormalFunc() { 
    } 
  };
 
  SampleCtrl.$inject = injectParams;
  angular.module('app.myModule').controller('SampleCtrl', SampleCtrl);
})();


/**************************
 * Factory 
 **************************/
(function () {
  'use strict';
  var injectParams = [ /* 'dependency1' */];
 
  function sampleFactory( /* dependency1 */) {
    var exports = {
      getData: getData
    };
 
    return exports;
    ////////////////
 
    function getData() { 
    } 
  }
 
  sampleFactory.$inject = injectParams;
  angular.module('app.myModule').factory('sampleFactory', sampleFactory);
})();

/**************************
 * Filter 
 **************************/
(function () {
  'use strict';
 
  function sampleFilter() {
 
    return sampleFilterFunc;
    ////////////////
 
    function sampleFilterFunc(parameters) {
      return parameters;
    } 
  }
 
  angular.module('app.myModule').filter('sampleFilter', sampleFilter);
})();

/**************************
 * Directive 
 **************************/
(function () {
  'use strict';
  var injectParams = [ /* 'dependency1' */];
 
  function customDirective( /* dependency1 */) {
 
    var directive = {
      link: link,
      restrict: 'EA',
      replace: true,
      templateUrl: 'app/myDirective/myDirective.html',
      controller: 'customController',
      controllerAs: 'custom'
    };
    return directive;
 
    function link(scope, element, attrs) {
    }
  };
 
  customDirective.$inject = injectParams;
  angular.module('app.myModule').directive('customDirective', customDirective);
})();

Introduction​

Ionic 2 is an open source cross platform application development framework. For the below questions your answer is YES and you can use the Ionic 2 for your app development.

1. I want to develop Apps for Android, iOS, Windows but don't know there respective technologies like Java for Android apps, objective-C/Swift for iOS apps, C# for windows apps ?
2. Do you know only web front-end technologies like HTML/CSS/Javascript  and  likes to develop mobile/tablet app?
3. We want to develop the app with less effort and faster ?

Ionic 2 apps can be developed with Angular 2 and preferably with  typescript.

 Development environment setup​

To install the development environment perform the below steps

1. Install Node.js 6 or greater  Download the installer
2. Open cmd and use the following commands to install the Ionic CLI and Cordova
   npm install -g ionic
   npm install -g cordova

Create a sample first app​

To create first sample app, Open the cmd window and use the below command
ionic start sampleApp --v2

1. To run your app, cd into the sampleApp directory

2. To run on browser  ionic serve

3. To run on ios ionic run ios

4. To run on Android ionic run android

5. To know the environment details use ionic info

Your system information:

Cordova CLI: 6.1.1  
Gulp version: CLI version 3.9.1  
Gulp local: Local version 3.9.1  
Ionic Framework Version: 2.0.0-rc.1  
Ionic CLI Version: 2.1.0  
Ionic App Lib Version: 2.1.0-beta.1  
OS: Windows 8.1  
Node Version: v6.2.1

Generate new Page and Service​

1. To create a page in the sampleApp  use

ionic g page [pageName]
ionic g page demoPage

CLI creates the following three files under 'sampleApp/src/pages/demo-page'

• demo-page.html -> the view code
• demo-page.ts -> component/class code similar to controller
• demo-page.scss -> your style/sass code

2. To create a service, replace page with provider:

ionic g provider [providerName]
ionic g provider demoData

CLI creates the demo-data.ts under 'sampleApp/src/providers/' folder this file serves likes service/factory.

3. Add DemoPage module in 'sampleApp\src\app\app.module.ts'

import { NgModule } from '@angular/core';  
import { IonicApp, IonicModule } from 'ionic-angular';  
import { MyApp } from './app.component';  
import { AboutPage } from '../pages/about/about';  
import { ContactPage } from '../pages/contact/contact';  
import { HomePage } from '../pages/home/home';  
import { TabsPage } from '../pages/tabs/tabs';  
import { DemoPage } from '../pages/demo-page/demo-page'; //import DemoPage   
  
@NgModule({  
  declarations: [ 
    MyApp,  
    AboutPage,  
    ContactPage,  
    HomePage,  
    TabsPage,  
    DemoPage //Add DemoPage  
  ],  
  imports: [ 
    IonicModule.forRoot(MyApp)  
  ],  
  bootstrap: [IonicApp],  
  entryComponents: [ 
    MyApp,  
    AboutPage,  
    ContactPage,  
    HomePage,  
    TabsPage,  
    DemoPage //Add DemoPage  
  ],  
  providers: []  
})  
export class AppModule {}  

Navigate to DemoPage​

1. Add button on Home.html

   Show DemoPage

2. Add the code to navigate in the HomePage class

    goToDemoPage(){  
    this.navCtrl.push(DemoPage);  
    }
   

3. Launch the app and click on the 'SHOW DEMOPAGE' Button you will be navigated to the DemoPage

Bingo !!! you created a new page and plugged in app and implemented the navigation.

1. Throwing Coins into a River:

The general reasoning given for this act is that it brings Good Luck. However, scientifically speaking, in the ancient times, most of the currency used was made of copper unlike the stainless steel coins of today. Copper is a vital metal very useful to the human body. Throwing coins in the river was one way our fore-fathers ensured we intake sufficient copper as part of the water as rivers were the only source of drinking water. Making it a custom ensured that all of us follow the practice.

2. Joining Both Palms together to Greet:

In Hindu culture, people greet each other by joining their palms – termed as “Namaskar.” The general reason behind this tradition is that greeting by joining both the palms means respect. However, scientifically speaking, joining both hands ensures joining the tips of all the fingers together; which are denoted to the pressure points of eyes, ears, and mind. Pressing them together is said to activate the pressure points which helps us remember that person for a long time. And, no germs since we don’t make any physical contact!

3. Why do Indian Women wear Toe Ring:

Wearing toe rings is not just the significance of married women but there is science behind it. Normally toe rings are worn on the second toe. A particular nerve from the second toe connects the uterus and passes to heart. Wearing toe ring on this finger strengthens the uterus. It will keep it healthy by regulating the blood flow to it and menstrual cycle will be regularized. As Silver is a good conductor, it also absorbs polar energies from the earth and passes it to the body.

4. Applying Tilak on the Forehead:

On the forehead, between the two eyebrows, is a spot that is considered as a major nerve point in human body since ancient times. The Tilak is believed to prevent the loss of “energy”, the red ‘kumkum’ between the eyebrows is said to retain energy in the human body and control the various levels of concentration. While applying kumkum the points on the mid-brow region and Adnya-chakra are automatically pressed. This also facilitates the blood supply to the face muscles.

5. Why do Temples have Bells:

People who are visiting the temple should and will Ring the bell before entering the inner sanctum (Garbhagudi or Garbha Gruha or womb-chamber) where the main idol is placed. According to Agama Sastra, the bell is used to give sound for keeping evil forces away and the ring of the bell is pleasant to God. However, the scientific reason behind bells is that their ring clears our mind and helps us stay sharp and keep our full concentration on devotional purpose. These bells are made in such a way that when they produce a sound it creates a unity in the Left and Right parts of our brains. The moment we ring the bell, it produces a sharp and enduring sound which lasts for minimum of 7 seconds in echo mode. The duration of echo is good enough to activate all the seven healing centres in our body. This results in emptying our brain from all negative thoughts.

6. Why do we have Navratras:

Our living style has drastically changed if we compare it to the society hundreds & thousands of years ago. The traditions which we follow in present are not establishments of today but of the past. Ever thought, why do we have Navratras twice a year unlike other festivals like Deepawali or Holi? Well, both these months are the months of changing seasons and the eating habits of both the seasons are quite different from each other. Navratras give enough time to the body to adjust and prepare itself for to the changing season. These nine days were marked as a period when people would clean their body system by keeping fasts by avoiding excessive salt and sugar, meditate, gain a lot of positive energy, gain a lot of self confidence & increase the self determination power (fasts are a medium to improve our will power and self determination) and finally get ready for the challenges of the changed season.

7. Why do we worship Tulsi Plant:

Hindu religion has bestowed ‘Tulsi’, with the status of mother. Also known as ‘Sacred or Holy Basil’, Tulsi, has been recognized as a religious and spiritual devout in many parts of the world. The vedic sages knew the benefits of Tulsi and that is why they personified it as a Goddess and gave a clear message to the entire community that it needs to be taken care of by the people, literate or illiterate. We try to protect it because it is like Sanjeevani for the mankind. Tulsi has great medicinal properties. It is a remarkable antibiotic. Taking Tulsi everyday in tea or otherwise increases immunity and help the drinker prevent diseases, stabilize his or her health condition, balance his or her body system and most important of all, prolong his or her life. Keeping Tulsi plant at home prevents insects and mosquitoes from entering the house. It is said that snakes do not dare to go near a Tulsi plant. Maybe that is why ancient people would grow lots of Tulsi near their houses.

8. Why do we worship Peepal Tree:

‘Peepal’ tree is almost useless for an ordinary person, except for its shadow. ‘Peepal’ does not a have a delicious fruit, its wood is not strong enough for any purpose then why should a common villager or person worship it or even care for it? Our ancestors knew that ‘Peepal’ is one of the very few trees (or probably the only tree) which produces oxygen even at night. So in order to save this tree because of its unique property they related it to God/religion.

9. Start with Spice & End with Sweet:

Our ancestors have stressed on the fact that our meals should be started off with something spicy and sweet dishes should be taken towards the end. The significance of this eating practice is that while spicy things activate the digestive juices and acids and ensure that the digestion process goes on smoothly and efficiently, sweets or carbohydrates pulls down the digestive process. Hence, sweets were always recommended to be taken as a last item.

10. Choti on the Male Head:

Sushrut rishi, the foremost surgeon of Ayurveda, describes the master sensitive spot on the head as Adhipati Marma, where there is a nexus of all nerves. The shikha protects this spot. Below, in the brain, occurs the Brahmarandhra, where the sushumnã (nerve) arrives from the lower part of the body. In Yog, Brahmarandhra is the highest, seventh chakra, with the thousand-petalled lotus. It is the centre of wisdom. The knotted shikhã helps boost this centre and conserve its subtle energy known as ojas.

11. Applying Mehendi/Henna on the Hand:

Besides lending color to the hands, mehndi is a very powerful medicinal herb. Weddings are stressful, and often, the stress causes headaches and fevers. As the wedding day approaches, the excitement mixed with nervous anticipation can take its toll on the bride and groom. Application of mehndi can prevent too much stress because it cools the body and keeps the nerves from becoming tense. This is the reason why mehndi is applied on the hands and feet, which house nerve endings in the body.

12. Celebration & Cleaning During Diwali:

Diwali usually falls in October or November which marks the start of winter season and end of rainy season. Rainy season wasn’t a good time for everyone back then; many homes needed repair and renovation after a heavy fall. That is why time before diwali was considered the period during which everyone can indulge in cleaning and beautification of their home. And also take out their winter clothes and pack the summer ones.

13. Sitting on the Floor & Eating:

This tradition is not just about sitting on floor and eating, it is regarding sitting in the “Sukhasan” position and then eating. Sukhasan is the position we normally use for Yoga asanas. Sitting in this position while eating helps in improving digestion as the circulatory system can focus solely upon digestion and not on our legs dangling from a chair or supporting us while we are standing.

14. Why not to sleep with Your Head towards North:

Myth is that it invites ghost or death but science says that it is because human body has its own magnetic field (Also known as hearts magnetic field, because the flow of blood) and Earth is a giant magnet. When we sleep with head towards north, our body’s magnetic field become completely asymmetrical to the Earth’s Magnetic field. That cause problems related to blood pressure and our heart needs to work harder in order to overcome this asymmetry of Magnetic fields. Apart from this another reason is that Our body have significant amount of iron in our blood. When we sleep in this position, iron from the whole body starts to congregate in brain. This can cause headache, Alzheimer’s Disease, Cognitive Decline, Parkinson disease and brain degeneration.

15. Surya Namaskar:

Hindus have a tradition of paying regards to Sun God early in the morning by their water offering ritual. It was mainly because looking at Sun rays through water or directly at that time of the day is good for eyes and also by waking up to follow this routine, we become prone to a morning lifestyle and mornings are proven to be the most effective part of the day.

16. Ear Piercing in Children:

Piercing the ears has a great importance in Indian ethos. Indian physicians and philosophers believe that piercing the ears helps in the development of intellect, power of thinking and decision making faculties. Talkativeness fritters away life energy. Ear piercing helps in speech-restraint. It helps to reduce impertinent behaviour and the ear-channels become free from disorders. This idea appeals to the Western world as well, and so they are getting their ears pierced to wear fancy earrings as a mark of fashion.

17. Application of Sindoor or Vermillion:

It is interesting to note that that the application of sindoor by married women carries a physiological significance. This is so because Sindoor is prepared by mixing turmeric-lime and the metal mercury. Due to its intrinsic properties, mercury, besides controlling blood pressure also activates sexual drive. This also explains why Sindoor is prohibited for the widows. For best results, Sindoor should be applied right upto the pituitary gland where all our feelings are centered. Mercury is also known for removing stress and strain.

18. The scientific explanation of ouching Feet(charan sparsh):

Usually, the person of whose feet you are touching is either old or pious. When they accept your respect which came from your reduced ego (and is called your shraddha) their hearts emit positive thoughts and energy (which is called their karuna) which reaches you through their hands and toes. In essence, the completed circuit enables flow of energy and increases cosmic energy, switching on a quick connect between two minds and hearts. To an extent, the same is achieved through handshakes and hugs. The nerves that start from our brain spread across all your body. These nerves or wires end in the fingertips of your hand and feet. When you join the fingertips of your hand to those of their opposite feet, a circuit is immediately formed and the energies of two bodies are connected. Your fingers and palms become the ‘receptor’ of energy and the feet of other person become the ‘giver’ of energy.

19. Why do we Fast:

The underlying principle behind fasting is to be found in Ayurveda. This ancient Indian medical system sees the basic cause of many diseases as the accumulation of toxic materials in the digestive system. Regular cleansing of toxic materials keeps one healthy. By fasting, the digestive organs get rest and all body mechanisms are cleansed and corrected. A complete fast is good for heath, and the occasional intake of warm lemon juice during the period of fasting prevents the flatulence. Since the human body, as explained by Ayurveda, is composed of 80% liquid and 20% solid, like the earth, the gravitational force of the moon affects the fluid contents of the body. It causes emotional imbalances in the body, making some people tense, irritable and violent. Fasting acts as antidote, for it lowers the acid content in the body which helps people to retain their sanity. Research suggests there are major health benefits to caloric restriction like reduced risks of cancer, cardiovascular diseases, diabetes, immune disorders etc.

20. Why Idol Worship:

Hinduism propagates idol worship more than any other religion. Researchers say that this was initiated for the purpose of increasing concentration during prayers. According to psychiatrists, a man will shape his thoughts as per what he sees. If you have 3 different objects in front of you, your thinking will change according to the object you are viewing. Similarly, in ancient India, idol worship was established so that when people view idols it is easy for them to concentrate to gain spiritual energy and meditate without mental diversion.

21. Why do Indian Women wear Bangles:

Normally the wrist portion is in constant activation on any human. Also the pulse beat in this portion is mostly checked for all sorts of ailments. The Bangles used by women are normally in the wrist part of ones hand and its constant friction increases the blood circulation level. Further more the electricity passing out through outer skin is again reverted to one’s own body because of the ring shaped bangles, which has no ends to pass the energy outside but to send it back to the body.

OpenGrok is a fast and usable source code search and cross reference engine. It helps you search, cross-reference and navigate your source code.

Requirements​

1. Create a folder 'C:OpenGrok'

2. Install JDK 1.7 or higher

   • Add 'JRE_HOME' environmental variable with value for JRE (eg: C:Program Files (x86)Javajre1.8.0_40)
   • Add Java.exe  path  (eg: C:Program Files (x86)Javajre1.8.0_40bin) in environmental PATH variable and restart computer

3. Download a Ctags from Ctags Windows Binary unzip and place it in C:OpenGrokCtags58 folder

4. Download and install Tomcat. To run Tomcat as a windows service open command prompt and navigate to 'TOMCAT_INSTALLbin' and execute 'service.bat install' command

OpenGork Setup​

1. Download and unzip Opengork  opengrok-0.12.1.tar.gz - Binary distribution to  'C:OpenGrok'

2. Extract the "source.war" file in the "C:OpenGrokopengrok-0.12.1lib"

3. Edit the WEB-INFweb.xml to include

• Path to configuration.xml that is generated  (CONFIGURATION )
• Location to the source being indexed. (SRC_ROOT)
• Location to the "Ctag" generated grokData  (DATA_ROOT)

https://gist.github.com/nagvbt/8378786674100270279c

4. Copy the the extracted source.war with the modified web.xml to the tomcat webapps folder.

5. Index the source and generate the configuration.xml file using the below command

   java -jar C:OpenGrokopengrok-0.12.1libopengrok.jar -W C:OpenGrokopengrok-0.12.1configuration.xml -c C:OpenGrokctags58ctags.exe -P -S -v -s D:Dev -d C:OpenGrokgrokdata

6. Launch Tomcat after the indexing in done. Open http://localhost:8080/source

7. Repeat step-5 tp re-index if you need to add new projects/pick new source etc.

All the web applications uses HTTP protocol. By nature HTTP is a stateless protocol so after every web request, the client disconnects from server and the ASP.NET engine discards the objects that were created for the page. This will avoid running out of server memory.

Levels of state management​

1. Control level: In ASP.NET, by default controls provide state management automatically.
2. Variable or object level: In ASP.NET, member variables at page level are stateless and thus we need to maintain state explicitly.
3. Single or multiple page level: State management at single as well as multiple page level i.e., managing state between page requests.
4. User level: State should be preserved as long as a user is running the application.
5. Application level: State available for complete application irrespective of the user, i.e., should be available to all users.
6. Application to application level: State management between or among two or more applications.

State Management techniques

State Management techniques are based on client side and server side. Their functionality differs depending on the change in state, so here is the hierarchy:

Client-side | Techniques

Client-Side State Management techniques are:

• View State
• Hidden field
• Cookies
• Control State
• Query Strings

Server-side | Technique

Server-Side State Management techniques are:

• Session State
• Application State

1. Make sure the latest service pack for Visual Studio is installed.
2. Disable Navigation Bar – Go to Tools > Options > Text Editor > C# or All Languages and uncheck Navigation bar.
3. Turn off animations – Go to Tools > Options > Environment and uncheck Animate environment tools.
4. Turn off Track Active Item – This will turn off jumping in the explorer whenever you select different files in different projects. Go to Tools > Options > Projects and Solutions and uncheck Track Active Item in Solution Explorer. This will ensure that if you are moving across files in different projects, the left pane will still be steady instead of jumping around.
5. Turn off Track Changes – Go to Tools > Options > Text Editor and uncheck Track changes. This will reduce overhead and speeds up IDE response.
6. Turn off HTML Validation – Go to Tools > Options > Text Editor > HTML > Validation and uncheck Show errors.
7. Turn off Start Page – Go to Tools > Options > Environment > Startup and select Load last loaded solution from the At Startup dropdown. This simply makes Visual Studio load faster when opening the application.

NOTE:

Above settings have been used for Visual Studio 2005 specifically but should still be of benefit for earlier and later versions of Visual Studio.

Contents

1. Introduction
2. How to find memory leak
3. Memory Leak and how to avoid it

Updated on : 17-Oct-2014

1. Introduction​

The failure to properly deallocate memory that was previously allocated is known as Memory Leak. The consequences of memory leaks is that the programs that leak large amounts of memory, or leak progressively, may display symptoms ranging from poor (and gradually decreasing) performance to running out of memory completely. Worse, a leaking program may use up so much memory that it causes another program to fail, leaving the user with no clue to where the problem truly lies. In addition, even harmless memory leaks may be symptomatic of other problems.

2. How to Find Memory Leak​

Use third-party tools like DevPartner or use the following steps to find the memory leaks

• Compile the project in "Debug" Mode.
• Declare the objects CMemoryState msOld, msNew, msDif;
• Check the memory state at one point. msOld.Checkpoint(); ://code ://code
• Check the memory state at onother point. msNew.Checkpoint();
• See for Difference msDif.Difference( msOld, msNew );
• Display the Leaked blocks in Debug window  msDif.DumpStatistics();

3. Memory Leak and How to avoid it​

a. Wrong usage of new/delete.

int* intArr; 
intArr = new int[500]; 
delete intArr; 

Use  delete[]intArr; instead of delete intArr as delete intArr is equal to deleting intArr[0];

b. Improper deletion of Array of Pointers

introwNo = 3; 
intcolsNo = 3; 
int *array = new int[rowNo];

for(inti=0; i < rowNo; i++) {
   array[i] = new int[i+1]; 
}

delete[] array; 

The cause of memory leak is that the 'array' is an array of pointers, with each of it's elements pointing to a separate memory block, so it is necessary free these blocks before freeing the array that holds the pointers.

for(int i=0; i < rowNo; i++) 
{
   delete[] array[i];
} 
    
delete [] array; 

c. Resource Handles: GDI Objects- CBrush, CPen, CFont, CBitmap, CPallete, CRgn and respective handles

CBrush myBr, *pOldBr; 
myBr.CreateSolidBrush(RGB(0, 255, 0)); 
pOldBr = pDC->SelectObject(&myBr); 
pDC->SelectObject(& myBr );
pDC->SelectObject(pOldBrush);

For more details Check:http://msdn.microsoft.com/en-us/library/windows/desktop/ms724291(v=vs.85).aspx

The DeleteObject method deletes the GDI object by freeing all system storage associated with it. The storage associated with the CGdiObject object is not affected by this call. An application should not call DeleteObject on a CGdiObject object that is currently selected into a device context. Use myBr.DeleteObject(); after finishing using myBr (Cbrush) object For handles pass handle of the DeleteObject function DeleteObject(hPen);

d. String conversions CString to LPTSTR

CString sName; 
sName= _T("Hello"); 
int lenName = sName.GetLength();
LPTSTR lpstrg = sName.GetBuffer(lenName); 

sName.ReleaseBuffer(); 
Cstring to BSTR CString csStr = "Hello"; 
BSTR bStr = csStr.AllocSysString(); 
 
SysFreeString(bStr); //finished using the BSTR 

Use ReleaseBuffer() when ever we create a buffer. Use SysFreeString() when ever we use AllocSysString() which allocates a new string of the type BSTR.

e. Improper deletion of pointer objects in a CList

CList<CMyData, CMyData> ptList;
CList<CMyData, CMyData> ptList; 
 ptList.RomoveAll(); //Improper deletion of pointer objects in a CArray CArray<CMyData, CMyData> ptArr;
 ptArr.RemoveAll(); 

Proper deletion of pointer objects in a CList

CList<CMyData, CMyData> ptList;
POSITION pos = ptList.GetHeadPosition();

while(pos!=NULL) { 
  delete ptList.GetNext(pos); 
  }

PtList.RomoveAll();

// Proper deletion of pointer objects in a CArray CArray<CMyData_, CMyData_\> ptArr; : : int i = 0;

while(i<ptArr.GetSize()) { 
  delete ptArr.GetAt(i++); 
  }

ptArr.RemoveAll(); 

f. Opening and proper closing of file and databases

CFile file; 
file.Open(szFilePath, CFile::modeCreate | CFile::modeWrite, 0); 
file.Write(chFile, chFileSize); 
file.Close(); 

e. Usage of Static Arrays

int Sample[500]; 

Never use static arrays if the array is dynamically growing. Instead of using static arrays use CArray or OCArray Example:

 CArray<int, int> Sample; 

Videos​

Beginners Windows Phone 8.1 development You need the Absolute Beginner Series for Windows Phone 8.1 It is a complete course in getting started for Windows Phone 8.1. source code for all the projects here.

Overview of the features available in Windows Phone 8.1 Watch the first session of the Jump Start.

Want to learn what is new  WP 8.1 You need the Building Apps For Windows Phone 8.1 Jump Start. source code is available here.

Blogs​

1. https://dev.windowsphone.com/en-us/develop

2. Windows Phone 8.1 for Developers–What Controls Are New