Three Possible Solutions
I know I'm coming late to the party, I've been looking if there were any new solutions to the variable configuration settings problem. There are a few answers that touch the solutions I have used in the past but most seem a bit convoluted. I thought I'd look at my old solutions and put the implementations together so that it might help people that are struggling with the same problem.
For this example I have used the following app setting in a console application:
<appSettings>
<add key="EnvironmentVariableExample" value="%BaseDir%\bin"/>
<add key="StaticClassExample" value="bin"/>
<add key="InterpollationExample" value="{0}bin"/>
</appSettings>
1. Use environment variables
I believe autocro autocro's answer touched on it. I'm just doing an implementation that should suffice when building or debugging without having to close visual studio. I have used this solution back in the day...
'
private void Test_Environment_Variables()
{
string BaseDir = ConfigurationManager.AppSettings["EnvironmentVariableExample"];
string ExpandedPath = Environment.ExpandEnvironmentVariables(BaseDir).Replace("\"", ""); //The function addes a " at the end of the variable
Console.WriteLine($"From within the C# Console Application {ExpandedPath}");
}
'
2. Use string interpolation:
Use the string.Format() function
`
private void Test_Interpollation()
{
string ConfigPath = ConfigurationManager.AppSettings["InterpollationExample"];
string SolutionPath = Path.GetFullPath(Path.Combine(System.AppDomain.CurrentDomain.BaseDirectory, @"..\..\"));
string ExpandedPath = string.Format(ConfigPath, SolutionPath.ToString());
Console.WriteLine($"Using old interpollation {ExpandedPath}");
}
`
3. Using a static class, This is the solution I mostly use.
`
private void Test_Static_Class()
{
Console.WriteLine($"Using a static config class {Configuration.BinPath}");
}
`
`
static class Configuration
{
public static string BinPath
{
get
{
string ConfigPath = ConfigurationManager.AppSettings["StaticClassExample"];
string SolutionPath = Path.GetFullPath(Path.Combine(System.AppDomain.CurrentDomain.BaseDirectory, @"..\..\"));
return SolutionPath + ConfigPath;
}
}
}
`
Project Code:
App.config:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />
</startup>
<appSettings>
<add key="EnvironmentVariableExample" value="%BaseDir%\bin"/>
<add key="StaticClassExample" value="bin"/>
<add key="InterpollationExample" value="{0}bin"/>
</appSettings>
</configuration>
Program.cs
using System;
using System.Configuration;
using System.IO;
namespace ConfigInterpollation
{
class Program
{
static void Main(string[] args)
{
new Console_Tests().Run_Tests();
Console.WriteLine("Press enter to exit");
Console.ReadLine();
}
}
internal class Console_Tests
{
public void Run_Tests()
{
Test_Environment_Variables();
Test_Interpollation();
Test_Static_Class();
}
private void Test_Environment_Variables()
{
string ConfigPath = ConfigurationManager.AppSettings["EnvironmentVariableExample"];
string ExpandedPath = Environment.ExpandEnvironmentVariables(ConfigPath).Replace("\"", "");
Console.WriteLine($"Using environment variables {ExpandedPath}");
}
private void Test_Interpollation()
{
string ConfigPath = ConfigurationManager.AppSettings["InterpollationExample"];
string SolutionPath = Path.GetFullPath(Path.Combine(System.AppDomain.CurrentDomain.BaseDirectory, @"..\..\"));
string ExpandedPath = string.Format(ConfigPath, SolutionPath.ToString());
Console.WriteLine($"Using interpollation {ExpandedPath}");
}
private void Test_Static_Class()
{
Console.WriteLine($"Using a static config class {Configuration.BinPath}");
}
}
static class Configuration
{
public static string BinPath
{
get
{
string ConfigPath = ConfigurationManager.AppSettings["StaticClassExample"];
string SolutionPath = Path.GetFullPath(Path.Combine(System.AppDomain.CurrentDomain.BaseDirectory, @"..\..\"));
return SolutionPath + ConfigPath;
}
}
}
}
Pre-build event:
Project Settings -> Build Events