Find if Key that has a null value exists in IConfiguration

Question

I have:

IConfiguration cfg;
string key;

I must detect if the key exists inside cfg when the key has a 'null' value.

I know the key is inside, I see it with the debugger, but I need a method to detect that.

I thought that cfg.GetSection(key).Exists() would return True.
But it always returns False.

According to documentation, cfg.GetSection(key) never returns null, even if key doesn't exist, so it is of no help.

Didn't you ask the same [How to know if a Key exists on IConfiguration](https://stackoverflow.com/questions/61779244/how-to-know-if-a-key-exists-on-iconfiguration) already? — Pavel Anikhouski, May 13 '20 at 19:28
I did ask - but there the answer was to use the ```Exists()``` method - but it doesn't work if the value is null — codeKnight, May 13 '20 at 19:29

Danielle · Accepted Answer · 2020-05-13T20:53:55.850

Use cfg.AsEnumerable() to get the keys that are inside the configuration.
You can log and see them:

foreach (var kv in cfg.AsEnumerable()) 
{
    Console.WriteLine("{0}: {1}", kv.Key, kv.Value);
}

=> So all you need to do is just find if the specific key you are looking for is in this IEnumerable.

var keyNames = cfg.AsEnumerable().ToDictionary(x => x.Key, x => x.Value);

if (keyNames.ContainsKey(keyName))
{
    keyExistsInConfiguration = true;
}

Find if Key that has a null value exists in IConfiguration

1 Answers1