Tuesday, August 6, 2013

MicroSoft DotNet Help: Windows Phone Application Development Event Life C...

MicroSoft DotNet Help: Windows Phone Application Development Event Life C...: Windows Phone Application Development Event  Life Cycle It is important for development to know Application life Cycle so tha...

Windows Phone Application Development Event Life Cycle


Windows Phone Application Development Event  Life Cycle


It is important for development to know Application life Cycle so that they can understand well

 

Easy to understand using below image:


Step 1:


 


Step 2:



 

I believe now you are understanding well, we can discuss briefly about application life cycle below


Event and States together make up for an application life cycle .In windows phone application life cycle events (4 type of event)


Windows Application life cycle Events:

1.    Launching

2.    Deactivated

3.    Activated

4.    Closing

Windows mobile have 3 type of application state

1.    Running

2.    Dormant

3.    Tombstoned

Events lead to change the application state




1. Launch Event:

 1. This event is raised when user launch the application

         รจ Mostly avoid this event for Application will get load quickly


Application Launching Event coding:( App.xaml.cs)


            // Code to execute when the application is launching (eg, from Start)

        // This code will not execute when the application is reactivated

        private void Application_Launching(object sender, LaunchingEventArgs e)

        {

 

        }


 1.1Running State:


            1. Once the application is launched its goes into Running state

            When Running State will appear?

1.    This state is on till the user doesn't navigate away from application

2.    The Phone is in Lock mode

 2. Deactivated Event:


          The user goes away from your application this event is raised

           In this application context and page should be saved

           When this application reactivated, that time save state should be restore


  Coding( App.xaml.cs)


  // Code to execute when the application is deactivated (sent to background)

        // This code will not execute when the application is closing

        private void Application_Deactivated(object sender, DeactivatedEventArgs e)

        {

        }

2.1        Dormant State:

 

-       Deactivated event goes into dormant state

-       In Dormant State the application is stopped ,but application in phone memory

-       Again application activate state that time phone need more memory,

(While activate application, that time state convert into Tombstoned state)

2.2        Tombstoned State:

-Once an application is terminated its goes into tombstoned state

-In this state the data and application state information preserved for maximum 5 application


Activated Event

 

When user switch back to a dormant or tombstoned application, this event is fired.

Developer should check the IsApplicationInstancePreserved property to know if the application is returning from being dormant or tombstoned state.

If it's value true, then the application was in dormant state else tombstoned state.



Coding: App.xaml.cs


        // Code to execute when the application is activated (brought to foreground)

        // This code will not execute when the application is first launched

        private void Application_Activated(object sender, ActivatedEventArgs e)

        {

            if (e.IsApplicationInstancePreserved == true)

            {

                //Dormant state

            }

            else

            {

                //tombstoned  state

            }

 

        }



Close Event


When the user navigates backwards from the first page of application, this event is fired.

Application gets terminated in this event and you get only 10 seconds to save any data if required.

For your Info : User does not have API for close application


Coding: App.xaml.cs


       // Code to execute when the application is closing (eg, user hit Back)

        // This code will not execute when the application is deactivated

        private void Application_Closing(object sender, ClosingEventArgs e)

        {

        }

 

 

 

 

Thursday, February 24, 2011

NAMING CONVENTIONS AND STANDARDS

NAMING CONVENTIONS AND STANDARDS

Naming Conventions

Consistency is the key to maintainable code. This statement is most true for naming your projects, source files, and identifiers including Fields, Variables, Properties, Methods, Parameters, Classes, Interfaces, and Namespaces.

General Guidelines

  1. Always use Camel Case or Pascal Case names.
  1. Avoid ALL CAPS and all lowercase names. Single lowercase words or letters are acceptable.
  1. Do not create declarations of the same type (namespace, class, method, property, field, or parameter) and access modifier (protected, public, private, internal) that vary only by capitalization.
  1. Do not use names that begin with a numeric character.
  1. Do add numeric suffixes to identifier names.
  1. Always choose meaningful and specific names.
  1. Always err on the side of verbosity not terseness.
  1. Variables and Properties should describe an entity not the type or size.
  1. Do not use Hungarian Notation!

Example:  strName or iCount

  1. Avoid using abbreviations unless the full name is excessive.
  1. Avoid abbreviations longer than 5 characters.
  1. Any Abbreviations must be widely known and accepted.
  1. Use uppercase for two-letter abbreviations, and Pascal Case for longer abbreviations.
  1. Do not use C# reserved words as names.
  1. Avoid naming conflicts with existing .NET Framework namespaces, or types.
  1. Avoid adding redundant or meaningless prefixes and suffixes to identifiers

Example:

//  Bad!

public enum ColorsEnum {…} public class CVehicle {…}

public  struct  RectangleStruct  {…}

  1. Do not include the parent class name within a property name.

Example: Customer.Name NOT Customer.CustomerName

  1. Try to prefix Boolean variables and properties with "Can", " Is" or " Has".
  1. Append computational qualifiers to variable names like Average, Count, Sum, Min, and Max where appropriate.
  1. When defining a root namespace, use a Product, Company, or Developer Name as the root. 

Example:

LanceHunt.StringUtilities

NAME USAGE & SYNTAX

1. Identifier: Project File

Naming Convention: Pascal Case. Always match Assembly Name & Root Namespace.

Example: LanceHunt.Web.csproj -> LanceHunt.Web.dll -> 

   namespace LanceHunt.Web

 

2. Identifier: Source File

Naming Convention: Pascal Case. Always match Class name and file name. Avoid including more than one Class, Enum (global), or Delegate (global) per file.  Use a descriptive file name when containing multiple Class, Enum, or Delegates.

 Example: MyClass.cs=> public  class  MyClass{…}

 

3. Identifier: Resource or Embedded File

Naming Convention: Try to use Pascal Case. Use a name describing the file contents.

 

4. Identifier: Namespace

Naming Convention: Pascal Case. Try to partially match Project/Assembly Name.

Example: namespace LanceHunt.Web {…}

 

5. Identifier: Class or Struct

Naming Convention: Pascal Case. Use a noun or noun phrase for class name. Add an appropriate class-suffix when sub-classing another type when possible.

Examples:

private  class  MyClass {…}

 internal  class  SpecializedAttribute  :  Attribute {…}

 public  class  CustomerCollection  :  CollectionBase {…}

 public  class  CustomEventArgs  :  EventArgs {…}

                                                                            private  struct  ApplicationSettings {…}

 

6. Identifier: Interface

Naming Convention: Pascal Case. Always prefix interface name with capital "I".

Example: interface  ICustomer{…}

 

7. Identifier: Generic Class &  Generic Parameter Type [C#v2+]

Naming Convention:Always use a single capital letter, such as T or K.

Example:

public  class  FifoStack<T>

{

 public  void  Push(<T>  obj) {…}

public  <T>  Pop(){…}

}

 

8. Identifier: Method

Naming Convention: Pascal Case. Try to use a Verb or Verb-Object pair.

Example: public  void  Execute(){…}private  string  GetAssemblyVersion(Assembly  target)  {…}

 

9. Identifier: Property

Naming Convention

Pascal Case. Property name should represent the entity it returns.  Never prefix property names with

"Get" or " Set".

 

Example:

public  string  Name

{

get{…} set{…} }

 

10. Identifier: Field(Public, Protected, or Internal)

Naming Convention: Pascal Case. Avoid using non-private Fields! Use Properties instead.

Example: public  string  Name;

protected  IList  InnerList;

 

11. Identifier: Field (Private)

Naming Convention: Camel Case and prefix with a single underscore (_) character.

Example: private  string  _name;

 

12. Identifier: Constant or Static Field

Naming Convention: Treat like a Field. Choose appropriate Field access-modifier above.

 

13. Identifier: Enum

Naming Convention:Pascal Case (both the Type and the Options). Add the FlagsAttribute to bit-mask multiple options.

Example:

public  enum  CustomerTypes

{ Consumer, Commercial}

 

14. Identifier: Delegate or Event

Naming Convention: Treat as a Field. Choose appropriate Field access-modifier above.

Example: public  event  EventHandler  LoadPlugin;

 

15. Identifier: Variable (inline)

Naming Convention: Camel Case. Avoid enumerating variable names like text1, text2, text3 etc.

 

16. Identifier: Parameter

Naming Convention: Camel Case.

Example: public  void  Execute(string  commandText,  int  iterations) {…}

 

 

Note :

The terms Pascal Casing and Camel Casing are used throughout this Book.

Pascal Casing - First character of all words are Upper Case and other characters are lower case.

Example: BackColor

Camel Casing - First character of all words, except the first word are Upper Case and other characters are lower case.

Example: backColor


 

 

 

 

 

 

    








1.Use Pascal casing for Class names

public class HelloWorld

{

     ...

}

2.    Use Pascal casing for Method names

void SayHello(string name)

{

     ...

}

3.    Use Camel casing for variables and method parameters

int totalCount = 0;

void SayHello(string name)

{

     string fullMessage = "Hello " + name;

     ...

}

4.    Use the prefix "I" with Camel Casing for interfaces ( Example: IEntity )

5.    Do not use Hungarian notation to name variables.

In earlier days most of the programmers liked it - having the data type as a prefix for the variable name and using m_ as prefix for member variables. Eg:

string m_sName;

int nAge;

However, in .NET coding standards, this is not recommended. Usage of data type and m_ to represent member variables should not be used. All variables should use camel casing.

Some programmers still prefer to use the prefix m_ to represent member variables, since there is no other easy way to identify a member variable.

6.    Use Meaningful, descriptive words to name variables. Do not use abbreviations.

Good:

string address

int salary

Not Good:

string nam

string addr

int sal

7.    Do not use single character variable names like i, n, s etc. Use names like index, temp

One exception in this case would be variables used for iterations in loops:

for ( int i = 0; i < count; i++ )

{

     ...

}

If the variable is used only as a counter for iteration and is not used anywhere else in the loop, many people still like to use a single char variable (i) instead of inventing a different suitable name.

 

 

8.    Do not use underscores (_) for local variable names.

9.    All member variables must be prefixed with underscore (_) so that they can be identified from other local variables.

10.  Do not use variable names that resemble keywords.

11.  Prefix boolean variables, properties and methods with "is" or similar prefixes.

       Ex: private bool _isFinished

12.  Namespace names should follow the standard pattern

<company name>.<product name>.<top level module>.<bottom level module>

13. Use appropriate prefix for the UI elements so that you can identify them from the rest of the variables.

There are 2 different approaches recommended here.

1. Use a common prefix ( ui_ ) for all UI elements. This will help you group all of the UI elements together and easy to access all of them from the intellisense.

2. Use appropriate prefix for each of the ui element. A brief list is given below. Since .NET has given several controls, you may have to arrive at a complete list of standard prefixes for each of the controls (including third party controls) you are using.

Control

Prefix

Label

Lbl

TextBox

Txt

DataGrid

Dtg

Button

Btn

ImageButton

imb

Hyperlink

Hlk

DropDownList

ddl

ListBox

lst

DataList

Dtl

Repeater

rep

Checkbox

Chk

CheckBoxList

cbl

RadioButton

rdo

RadioButtonList

rbl

Image

Img

Panel

pnl

PlaceHolder

phd

Table

tbl

Validators

val

14.  File name should match with class name.

For example, for the class HelloWorld, the file name should be helloworld.cs (or, helloworld.vb)

15.  Use Pascal Case for file names.

 

INDENTATION AND SPACING

1.    Use TAB for indentation. Do not use SPACES.  Define the Tab size as 4.

2.    Comments should be in the same level as the code (use the same level of indentation).

Good:

// Format a message and display

string fullMessage = "Hello " + name;

DateTime currentTime = DateTime.Now;

string message = fullMessage + ", the time is : " + currentTime.ToShortTimeString();

MessageBox.Show ( message );

Not Good:

// Format a message and display

string fullMessage = "Hello " + name;

 DateTime currentTime = DateTime.Now;

string message = fullMessage + ", the time is : " + currentTime.ToShortTimeString();

 MessageBox.Show ( message );

3.    Curly braces ({}) should be in the same level as the code outside the braces.


4.    Use one blank line to separate logical groups of code.

Good:

                                                                                                                             bool SayHello ( string name )

                                                                                                                             {

                                                                                                                                                                 string fullMessage = "Hello " + name;

                                                                                                                                                                 DateTime currentTime = DateTime.Now;

                                                                                                                                                                 string message = fullMessage + ", the time is : " + currentTime.ToShortTimeString();

                                                                                                                                                          MessageBox.Show ( message );

                                                                                                                                                                 if ( ... )

                                                                                                                                                                 {

                                                                                                                                                                 // Do something                                    // ...

                                                                                                                                                                 return false;

                                                                                                                                                                 }

                                                                                                                                                                      return true;

                                                                                                                                                                 }

Not Good:

                                                                                                                                                     bool SayHello (string name)

                                                                                                                                                     {

                                                                                                                                                                 string fullMessage = "Hello " + name;

                                                                                                                                                                 DateTime currentTime = DateTime.Now;

                                                                                                                                                                 string message = fullMessage + ", the time is : " + currentTime.ToShortTimeString();

                                                                                                                                                          MessageBox.Show ( message );

                                                                                                                                                                 if ( ... )

                                                                                                                                                                 {

                                                                                                                                                     // Do something                 // ...

                                                                                                                                                     return false;

                                                                                                                                                                 }

                                                                                                                                         return true;

                                                                                                                                         }

5.    There should be one and only one single blank line between each method inside the class.

6.    The curly braces should be on a separate line and not in the same line as if, for etc.

Good:

                                                                                                                                         if ( ... ) 

                                                                                                                                                                 {

                                                                                                                                                                 // Do something

                                                                                                                                                                             }

Not Good:

                                                                                                                                         if ( ... )  {

                                                                                                                                                     // Do something                             }

7.    Use a single space before and after each operator and brackets.

Good:       if ( showResult == true )

                                                                                                                 {

                                                                                                                                         for ( int i = 0; i < 10; i++ )

                                                                                                                                                                 {  //          }

                                                                                                                 }

Not Good:

                                                                                                                 if(showResult==true)

                                                                                                                 {

                                                                                                                             for(int     i= 0;i<10;i++)

                                                                                                                                                     {

                                                                                                                                                                                  //

                                                                                                                                                     }                                                                           

                                                                                                     }

8.    Use #region to group related pieces of code together. If you use proper grouping using #region, the page should like this when all definitions are collapsed.

 

 

9.    Keep private member variables, properties and methods in the top of the file and public members in the bottom. 

THE FOLLOWING TABLE SUMMARIZES THE CAPITALIZATION RULES AND PROVIDES EXAMPLES FOR THE DIFFERENT TYPES OF IDENTIFIERS:

 

IDENTIFIER

 

CASE

 

EXAMPLE

Class

Pascal

AppDomain

Enum type

Pascal

ErrorLevel

Enum values

Pascal

FatalError

Event

Pascal

ValueChange

Exception class

Pascal

WebException

Note   Always ends with the suffix Exception.

Read-only Static field

Pascal

RedValue

Interface

Pascal

IDisposable

Note   Always begins with the prefix I.

Method

Pascal

ToString

Namespace

Pascal

System.Drawing

Parameter

Camel

typeName

Property

Pascal

BackColor

 

Protected instance field

Camel

redValue

Note   Rarely used. A property is preferable to using a protected instance field.

Public instance field

Pascal

RedValue

Note   Rarely used. A property is preferable to using a public instance field.