Rewriting IConfiguration appsettings.json with Command Line Arguments in C# 10 .NET 6

Question

I'm making console application in C# 10 .NET 6 using the Dependency Injection. I have an appsettings.json file that i load by IConfiguration but i have also added a custom IConfigurationSource that loads data in a specific way by the Command Line Arguments. It works because if i write a CLA that overrides an appsettings.json property then it does. What I want to do is that if i override a particular appsettings.json property via CLA I want it to update the property inside the appsettings.json file so I don't have to start the application with the same CLA again and again. How do I accomplish that?

private IConfiguration SetUpConfiguration()
{
    IConfiguration configuration = new ConfigurationBuilder()
    .AddAppSettingsFile()
    .AddCommandLineArgumentBuilder(_args)
    .Build();
    return configuration;
}

I Wrote it in a simplified version to make you see the "structure" of what I wrote.

private IConfiguration SetUpConfiguration()
{
    IConfiguration configuration = new ConfigurationBuilder()
    .AddAppSettingsFile()
    .AddCommandLineArgumentBuilder(_args)
    .Build();
    return configuration;
}

I Wrote it in a simplified version to make you see the "structure" of what I wrote.

jeanluc162 · Answer

You need to derive from JsonConfigurationProvider and override the Set-Method so it actually writes values back to the file.

Rewriting IConfiguration appsettings.json with Command Line Arguments in C# 10 .NET 6

1 Answers