Monitor the file system with FileSystemWatcher in C# .NET

January 4, 2017 Leave a comment

In this post we’ll look at how you can use the FileSystemWatcher object to monitor the Windows file system for various changes.

A FileSystemWatcher object enables you to be notified when some change occurs in the selected part of the file system. This can be any directory, such as “c:\” or any subdirectory under the C: drive. So if you’d like to make sure you’re notified if a change occurs on e.g. “c:\myfolder” – especially if it’s editable by your colleagues – then FileSystemWatcher is a good candidate.

Consider the following Console application:

Read more of this post

Filed under .NET, Files and directories Tagged with ,

Reformatting extracted substrings using Match.Result in C# .NET

January 3, 2017 2 Comments

Say you have the following Uri:

http://localhost:8080/webapps/bestapp

…and you’d like to extract the protocol and the port number and concatenate them. One option is a combination of a regular expression and matching groups within the regex:

Read more of this post

Filed under .NET Tagged with , ,

Packing and unpacking files using Zip archives in .NET

January 2, 2017 Leave a comment

We’ve looked at a couple of (de)compression techniques available in .NET in previous posts, see link below. Here we’ll look at how to compress multiple files into well-known ZIP files using .NET.

.NET4.5 has added native support for ZIP files, though you need to add the following library to reach the new functions:

New system compression dll

Say you’d like to compress all files within a folder:

Read more of this post

Filed under .NET, Files and directories Tagged with , ,

Compressing and decompressing files with BZip2 in .NET C#

January 1, 2017 Leave a comment

BZip2 is yet another data compression algorithm, similar to GZip and Deflate. There’s no native support for BZip2 (de)compression in .NET but there’s a NuGet package provided by icsharpcode.net.

Read more of this post

Filed under .NET, Files and directories Tagged with , ,

Replacing substrings using Regex in C# .NET: phone number example

December 31, 2016 1 Comment

In this post we saw an application of Regex and Match to reformat date strings. Let’s check another example: change the following phone number formats…:

  • (xxx)xxx-xxxx: (123)456-7890
  • (xxx) xxx-xxxx: (123) 456-7890
  • xxx-xxx-xxxx: 123-456-7890
  • xxxxxxxxxx: 1234567890

…into (xxx) xxx-xxxx.

Here’s a possible solution:

private static string ReformatPhone(string phone)
{
	Match match = Regex.Match(phone, @"^\(?(\d{3})\)?[\s\-]?(\d{3})\-?(\d{4})$");
	return string.Format("({0}) {1}-{2}", match.Groups[1], match.Groups[2], match.Groups[3]);
}

If you call this function with any of the above 4 examples it will return “(123) 456-7890”.

View all posts related to string and text operations here.

Filed under .NET Tagged with ,

Compressing and decompressing strings with BZip2 in .NET C#

December 30, 2016 Leave a comment

There are times when you need to return a large text from a web service. The large text will then need to be handled by the recipient. In order to reduce the size of the message you can combine two simple techniques:

  • Compress the string value with a compression algorithm, such as BZip2
  • Base64 encode the resulting byte array

You will be able to send the base 64 encoded compressed string over the wire.

Read more of this post

Filed under .NET Tagged with , ,

How to create custom string formatters with C# .NET

December 29, 2016 Leave a comment

.NET has a fairly large number of built-in string formatters that you can pass into the string.Format method. Here are some examples from the MSDN page about formatting:

String.Format("{0,-12}{1,8:yyyy}{2,12:N0}{3,8:yyyy}{4,12:N0}{5,14:P1}",
                                city.Item1, city.Item2, city.Item3, city.Item4, city.Item5,
                                (city.Item5 - city.Item3)/ (double)city.Item3);
String.Format("{0,-12}{1,8}{2,12}{1,8}{2,12}{3,14}\n",
                                    "City", "Year", "Population", "Change (%)");
String.Format("{0,-10:C}", 126347.89m);

The IFormatProvider and ICustomFormatter interfaces will provide you with the methods required to create your own formats.

Read more of this post

Filed under .NET, C# language features Tagged with

Using NumberStyles to parse numbers in C# .NET

December 28, 2016 1 Comment

There are a lot of number formats out there depending on the industry we’re looking at. E.g. negative numbers can be represented in several different ways:

  • -14
  • (14)
  • 14-
  • 14.00-
  • (14,00)

…and so on. Accounting, finance and other, highly “numeric” fields will have their own standards to represent numbers. Your application may need to parse all these strings and convert them into proper numeric values. The static Parse method of the numeric classes, like int, double, decimal all accept a NumberStyles enumeration. This enumeration is located in the System.Globalization namespace.

Read more of this post

Filed under .NET

Getting the byte array of a string depending on Encoding in C# .NET

December 27, 2016 Leave a comment

You can take any string in C# and view its byte array data depending on the Encoding type. You can get hold of the encoding type using the Encoding.GetEncoding method. Some frequently used code pages have their short-cuts:

  • Encoding.ASCII
  • Encoding.BigEndianUnicode
  • Encoding.Unicode – this is UTF16
  • Encoding.UTF7
  • Encoding.UTF32
  • Encoding.UTF8

Read more of this post

Filed under .NET, Globalization Tagged with , ,

Using DateTimeFormatInfo to localise date and time in .NET C#

December 26, 2016 Leave a comment

Every programmer loves working with dates and time, right? Whether or not you like it it is inevitable to show the dates in a format that the viewer understands. You should not show dates presented according to the US format in Japan and vice versa.

The DateTimeFormatInfo class includes a range of useful properties to localise date and time. The entry point to the DateTimeFormatInfo class is CultureInfo. E.g. if you’d like to format a date according to various cultures – Swedish, Hungarian and German – then you can do it as follows:

Read more of this post

Filed under .NET, C# language features, Globalization Tagged with ,

← Older posts

Newer posts →

Elliot Balynn's Blog

A directory of wonderful thoughts

Software Engineering

Web development

Disparate Opinions

Various tidbits

chsakell's Blog

WEB APPLICATION DEVELOPMENT TUTORIALS WITH OPEN-SOURCE PROJECTS

Once Upon a Camayoc

ARCHIVED: Bite-size insight on Cyber Security for the not too technical.