. Net Discussion

This really works for me.

Apart from convariance and contravariance available in assignments, parameter types and return types, it is available for genericand delegate types also from C# 4.0 onwards. Covariant types convert from a wider type to narrower type. (e.g., int  to short.).Contravariant types convert from a narrower type to a wider type(For example, from string to object.).

 Output: Contravariant
 Output: Covariant

ExpandoObject class provides us the capability to add and delete members of its instances at runtime and also to set and get values of these members. We have to use System.Dynamic namespace to use this class. We must use the dynamic keyword to enable late binding for an instance of the ExpandoObject class.

    Output :

Tuple is available from .net 4.0. It allows us to capture related values without creating a new class. It is much flexible that the KeyValuePair class, because it can hold up to 8 values of different types.

    Output:

Features of C# -Default keyword

I’m working in .Net 1.1 application.




 

Hi All,

I have a question regarding FileStream and StreamWriter. I am doing
the below IO operation in my project .But, it throws the error of "The
process cannot access the file because it is used by another process"
in below highlighted line.


string filePath = "C:/Test/Folder1"
string fileName =
DateTime.Today.Day.ToString() + DateTime.Today.Month.ToString() +
DateTime.Today.Year.ToString();
string fullFilePath = filePath + "_" +
fileName + ".txt";
FileStream fs = new
FileStream(fullFilePath, FileMode.Append, FileAccess.Write);
if (!File.Exists(fullFilePath))
{
fs = new FileStream(fullFilePath,
FileMode.CreateNew, FileAccess.Write);
}
StreamWriter sw = new StreamWriter(fs);
sw.Write("Test" );
sw.Close();
sw.Dispose();
fs.Close();
fs.Dispose();


So, If you know the solution then kindly reply me only. Thanks in advance..:)


Thanks & Regards,
Sanjiv

SOLUTION 1:

Hi Sanjiv,

You have to use using keyword to avoid such access behaviors

string filePath = "C:/Test/Folder1";
string fileName = DateTime.Today.Day.ToString() +
DateTime.Today.Month.ToString() + DateTime.Today.Year.ToString();
string fullFilePath = filePath + "_" + fileName + ".txt";
FileMode _fm = FileMode.Append;

if (!File.Exists(fullFilePath))
_fm = FileMode.CreateNew;

using (FileStream fs = new FileStream(fullFilePath, _fm,
FileAccess.Write))
{
StreamWriter sw = new StreamWriter(fs);
sw.Write("Test");
sw.Close();
sw.Dispose();
fs.Close();
fs.Dispose();
}


More reference


• http://msdn.microsoft.com/en-us/library/yh598w02.aspx

• http://www.codeproject.com/Articles/17106/The-using-Keyword-in-C

-Oli.

 

Thanks in advance for the help

 

-Khan

We have an ASP.net web forms application developed on .net 4.0 and has around 10 Pages approximately. Currently the web forms are designed only for desktop web browsers. We need to provide the business with the option of enabling it for the Mobile.

We have requirement to read a text from scanned pdf document which has text as embedded image. We have considered using itextsharp and ghost script for this requirement. Please help us if there any other open source which would be best suitable for our requirement. Any suggestion would be really appreciated

SOLUTION 1:

You can use below Microsoft's SDK for this.

Microsoft Office Document Imaging -
http://social.technet.microsoft.com/Forums/en-US/officeappcompat/thread/93d6f285-dc98-46e2-b7e0-872bba9c4e35/[^]

I had evaluated several Third Party OCR SDK's in one of my assignment. In case if you are open for Third Party OCR SDK then search below SDK's on Google.

1) Nuance OmniPage OCR
2) Accusoft SmartZone OCR