Tips and tricks in C# .NET
January 11, 2017 Leave a comment
Occasionally you need to extract some information from a free-text form. Consider the following text:
First name: Elvis
Last name: Presley
Address: 1 Heaven Street
City: Memphis
State: TN
Zip: 12345
Say you need to extract the full name, the address, the city, the state and the zip code into a pipe-delimited string. The following function is one option:
January 10, 2017 1 Comment
There’s a special storage location for a .NET application on Windows that is allocated to that application. It’s called isolated storage and it’s an optimal place to store files by an application that doesn’t have full access to the file system. Writing to and reading from isolated storage doesn’t require any extra security check. An application without full access to the file system will be able to use its allocated slot in isolated storage and nothing else. It’s an ideal mechanism for storing e.g. application state.
However, don’t confuse isolated storage with file security. It is still a “normal” location on disk with a file path. A typical location is under users/[username]/appdata/local. Therefore you or full-trust applications can still find and modify the files saved in isolated storage. However, limited-trust applications won’t be able to access any other part of the file system.
January 9, 2017 Leave a comment
It’s trivial to create a temporary file using the Path class in .NET. Let’s first see how to find the path to the current user’s temp folder:
string tempFolderPath = Path.GetTempPath();
In my case it returns C:\Users\andras.nemes\AppData\Local\Temp\ which is the same as the value of the TEMP environment variable at the user level on my PC.
January 8, 2017 1 Comment
In this post we saw how to enumerate all WMI – Windows Management Intrumentation – namespaces and classes. Then in this post we saw an example of querying the system to retrieve all local drives:
January 7, 2017 1 Comment
In this post we saw how to determine if two arrays are structurally equal in .NET. Two arrays are said to be structurally equal if they contain the same elements in the same order.
Structural equality has a comparison counterpart: IStructuralComparable. It determines if an array comes before or after or is equal to another array based on the elements within it.
January 6, 2017 Leave a comment
.NET has the necessary objects to enable TCP-level messaging in the System.Net.Sockets namespace. The key objects to build an extremely simple TCP server are TcpListener and Socket. The TCP client and server can communicate in a stream-like fashion over the network using the NetworkStream object.
Here’s an example of how a TCP server can ingest the message of a single client:
January 5, 2017 1 Comment
In this we saw how to convert between numeric types explicitly and implicitly. There are other ways to implement conversions in C#. You must have come across the System.Convert static methods such as System.ConvertToInt32 or System.ConvertToByte.
You can implement your own conversions by implementing the IConvertible interface. Consider the following object:
public class House
{
public double Area { get; set; }
public int NumberOfRooms { get; set; }
public string Address { get; set; }
public bool ForSale { get; set; }
public DateTime DateBuilt { get; set; }
}
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:
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:
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:
Say you’d like to compress all files within a folder:
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Exercises in .NET with Andras Nemes 