Criticism associated with DOT NET

Performance

C# programs, like all programs written for the .NET and other virtual machine environments such as Java, tend to require more system resources than functionally similar applications that access machine resources more directly.

Platform

Microsoft’s current .NET implementation is only available on Windows.

Reference : Dilip Kumar Jena ( https://mstechexplore.wordpress.com )

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DOT NET 3.0 – Features of C# 3.0

C# 3.0 is the current version, and was released on 19 November 2007 as part of .NET Framework 3.5. It includes new features inspired by functional programming languages such as Haskell and ML, and is driven largely by the introduction of the Language Integrated Query (LINQ) pattern to the Common Language Runtime.[9]

C# 3.0 was unveiled at the 2005 Professional Developers Conference. It is not currently standardized by any standards organisation, though it is expected that it will eventually become an ECMA and then ISO standard, as did its predecessors.

Reference : Dilip Kumar Jena ( https://mstechexplore.wordpress.com )

DOT NET 4.0 – Design goals for C#.NET

The ECMA standard lists these design goals for C#:

  • C# is intended to be a simple, modern, general-purpose, object-oriented programming language.
  • Because software robustness, durability and programmer productivity are important, the language should include strong type checking, array bounds checking, detection of attempts to use uninitialized variables, source code portability, and automatic garbage collection.
  • The language is intended for use in developing software components that can take advantage of distributed environments.
  • Programmer portability is very important, especially for those programmers already familiar with C and C++.
  • Support for internationalization is very important.
  • C# is intended to be suitable for writing applications for both hosted and embedded systems, ranging from the very large that use sophisticated operating systems, down to the very small having dedicated functions.

Reference : Dilip Kumar Jena ( https://mstechexplore.wordpress.com )

Dot Net – How to upload excel sheet into databse using Dataset in ASP.NET

I thought of writing this blog post because there can a number of occasion where in you might need to upload something from word file or excel sheet or it can be any kind of  file need to be inserted into the database what we can do many things.

But probably what I feel good and follow most of the time is doing this way so that we can preserve the statements for future reference what we have actually used and where it is going to exactly affect.

Step 1: Create  a website and then add default page on to it.

Step 2: Write the following code in Page_Load(object sender, EventArgs e) function

DataSet ds = new DataSet();

OleDbConnection myCon = new OleDbConnection(@”Provider=Microsoft.Jet.OLEDB.4.0;Data Source=folderpath\sheet.xls;Extended Properties=Excel 8.0;”);

OleDbCommand myComm = new OleDbCommand(“select * from [sheet1$] where State<>””, myCon);

OleDbDataAdapter da = new OleDbDataAdapter(myComm);

da.Fill(ds);

for (int i = 0; i < ds.Tables[0].Rows.Count;i++ )

{

Response.Write(“insert into dbo.Temp2 values(‘” + ds.Tables[0].Rows[i][0].ToString() + “‘,'” + ds.Tables[0].Rows[i][1].ToString() + “‘,'” + ds.Tables[0].Rows[i][2].ToString() + “‘,'” + ds.Tables[0].Rows[i][3].ToString() + “‘)<br />”);

}

myCon.Close();

Step 3: Create a table in SQL Server names Temp2 where in u want insert the excel sheet into.

NOTE: The table name can be any name  you like its just an example never take it as standard, its for learing.

create table Temp2(Id varchar(10),country varchar(100),natAnimal varchar(50),lang varchar(50))

Step 4: Create or if u have  excel sheet just make sure that that contains header for each column it will be easy to understand

EX:

State Country Animal Language
1 Australia Kangroo English
2 India Peacock Hindi
3 USA American Biston English

This is a sample excel sheet name it as sheet and inside as Sheet1 it will be applied by default so just hit the save button.

So all set!!!

now save the excel sheet in the folder of your website and run the web site the expected Output will be something like this will appear in your broswer

insert into dbo.Temp2 values(‘1′,’Australia’,’Kangroo’,’English’)

insert into dbo.Temp2 values(‘2′,’India’,’Peacock ‘,’Hindi’)

insert into dbo.Temp2 values(‘3′,’USA’,’American Biston’,’English’)

then copy it and paste in ssms (SQL server Query Editor and hit F5 to execute) Finally records are inserted into the database.

There can be many more ways I am sure but this is also handy when you have production and development section seperate.

Reference : Dilip Kumar Jena ( https://mstechexplore.wordpress.com )

DotNet FrameWork – What actually happens when you add something to an arraylistcollection – How Boxing and unboxing occures in memory – Why only boxed types can be unboxed – Day 30 of 30

What actually happens when you add  something to an arraylistcollection ?

Following things will happen :

Arraylist is a dynamic array class in c# in System.Collections namespace derived from interfaces – ICollection , IList , ICloneable , IConvertible  . It terms of in memory structure following is the implementation .

a. Check up the total space if there’s any free space on the declared list .

b. If yes add the new item and increase count by 1 .

c. If No Copy the whole thing to a temporary Array of Last Max. Size .

d. Create new Array with size ( Last Array Size + Increase Value )

e. Copy back values from temp and reference this new array as original array .

f. Must doing Method updates too , need to check it up .

What is Boxing and unboxing? Does it occure automaatically or u need to write code to box and unbox?

Boxing – Process of converting a System.ValueType to Reference Type , Mostly base class System.Object type and allocating it memory on Heap .Reverse is unboxing , but can only be done with prior boxed variables.

Boxing is always implicit but Unboxing needs to be explicitly done via casting , thus ensuring the value type contained inside .

How Boxing and unboxing occures in memory?

Boxing converts value type to reference type , thus allocating memory on Heap . Unboxing converts already boxed reference types to value types through explicit casting , thus  allocating memory on stack .

Why only boxed types can be unboxed?

Unboxing is the process of converting a Reference type variable to Value type and thus allocating memory on the stack . It happens only to those Reference type variables that have been earlier created by Boxing of a Value Type , therefore internally they contain a value type , which can be obtained through explicit casting . For any other Reference type , they don’t internally contain a Value type to Unboxed via explicit casting . This is why only boxed types can be unboxed .

Please read all the post in the Dotnet Framework series.

Reference : Dilip Kumar Jena ( https://mstechexplore.wordpress.com )

DotNet FrameWork – What is the difference between typeof(foo) and myFoo.GetType() – Day 28 of 30

What is the difference between typeof(foo) and myFoo.GetType()?

Typeof is operator which applied to a object returns System.Type object. Typeof cannot be overloaded white GetType has lot of overloads.GetType is a method which also returns System.Type of an object. GetType is used to get the runtime type of the object.

Example from MSDN showing Gettype used to retrive type at runtime:-

public class MyBaseClass: Object {   ………………..   }

public class MyDerivedClass: MyBaseClass {  ………………   }

public class Test {

public static void Main() {

MyBaseClass myBase = new MyBaseClass();

MyDerivedClass myDerived = new MyDerivedClass();

object o = myDerived;

MyBaseClass b = myDerived;

Console.WriteLine(“mybase: Type is {0}”, myBase.GetType());

Console.WriteLine(“myDerived: Type is {0}”, myDerived.GetType());

Console.WriteLine(“object o = myDerived: Type is {0}”, o.GetType());

Console.WriteLine(“MyBaseClass b = myDerived: Type is {0}”, b.GetType());

}

}

/*

This code produces the following output.

mybase: Type is MyBaseClass

myDerived: Type is MyDerivedClass

object o = myDerived: Type is MyDerivedClass

MyBaseClass b = myDerived: Type is MyDerivedClass

*/

Can “this” be used within a static method?

No ‘This’ cannot be used in a static method. As only static variables/methods can be used in a static method.

Please read all the post in the Dotnet Framework series.

Reference : Dilip Kumar Jena ( https://mstechexplore.wordpress.com )