C# on Remko's Blog

Returning a string from unmanaged dll to .net

Wed, 13 Mar 2013 10:01:31 +0000

I write most of my code in unmanaged languages such as Delphi and C/C++. Sometimes customers ask me to interface my code to their .net code in which case I create a dll for them.

A recurring thing is that I need to return string to .net.

There are many ways to do this of course but in all cases we need to manage memory: who will allocate the memory for the string and who is responsible for freeing it?

Convert an IP Address to an Integer in C# in host byte ordering

Sat, 13 Oct 2012 15:18:26 +0000

Yesterday I wrote about converting an IP Address to an Integer in C#. But both methods I presented return the IP Address in network byte order.

However in some cases, especially when calling WinApi functions, you will need to convert the Integer to host byte order which is little-endian on Intel processors.

warning CS0618: 'System.Net.IPAddress.Address' is obsolete

Fri, 12 Oct 2012 13:43:21 +0000

For a call to a WinApi function I needed to convert an IP Address to an Integer in C#.

This can be done using the System.Net.IPAddress class:

Using Address Property · c# Download

using System.Net;

IPAddress ipa = IPAddress.Parse("10.4.2.91");
uint ip = (uint)ipa.Address;

Although this works, the compiler issues a warning:

Calling a function inside another assembly in .NET

Wed, 22 Aug 2012 09:42:06 +0000

I wanted to call a hash function from a .net executable from my code. My first step was to inspect the executable with Reflector.

The Hash function was in a namespace called Core:

namespace Core · c# Download

namespace TheExe.Core
{
 internal static class AssemblyInfo
 internal static class StringExtensionMethods
}

internal static class StringExtensionMethods
{
 // Methods
 public static string Hash(this string original, string password);
 // More methods...
}

Notice that the Core namespace is marked as internal so it was not meant to be callable outside of the executable. It's still possible to call it using Reflection:

Making String.IndexOf case insensitive

Sat, 29 Jan 2011 10:41:24 +0000

I don't do much programming in .NET based languages but I have to for some things like the Windows Live Writer plugin I am creating.

I didn't expect this but the String.IndexOf Method is by default case sensitive.

But we can make it case insensitive if we use one of the overloads: IndexOf(String, StringComparison).