How can I express this nested loop in LINQ?-CodePudding

Background:

I have ASP.NET Core app. I'm trying to write server-side validation errors to the log.
If ASP.NET Core model validation detects any error in any field in the webform, then ModelState.IsValid is false.
Every field in the webform is listed in ModelState.Values
If a "Value" has one or more errors, then Value.Errors.Count > 0
I want to log a) the webform field name (the Value's "key") and b) each error message for that field.
I'd like to include all this information in a single line (i.e. a single C# "string").

Current code:

// LOG:
//   2022-10-24 09:37:29.0909|Error|ServiceMenu.Q255: The value '' is invalid. 
//   2022-10-24 09:37:35.4096|Error|ServiceMenu.Q265: The value '' is invalid. 
if (!ModelState.IsValid)
{
    foreach (var k in ModelState.Keys)
    {
        var v = ModelState[k];
        if (v.Errors.Count > 0)
        {
            string s = k   ": ";
            for (int i=0; i < v.Errors.Count - 1; i  )
                s  = v.Errors[i].ErrorMessage   ", ";
            s  = v.Errors[v.Errors.Count - 1].ErrorMessage;
            _logger.LogError(s);
        }
    }
    return Page();
}

Sample output (two required fields, Q255 and 265, were blank):

2022-10-24 09:37:29.0909|Error|ServiceMenu.Q255: The value '' is invalid. 
2022-10-24 09:37:35.4096|Error|ServiceMenu.Q265: The value '' is invalid.

Q: Can I simplify this nested loop with LINQ?

Update:

Thank you, everybody.
Evk and T.S. are both absolutely correct: "Don't think that using LINQ is always good." I don't - and their point is very well taken :)
Oliver Weichhold gave me the syntax I was looking for :)

Here's the code I finally wound up with:

// EXAMPLE LOG:
//   2022-10-24 13:24:10.5242|Error|ServiceMenu.Q255: The value '' is invalid. 
//   2022-10-24 13:24:24.9692|Error|ServiceMenu.Q265: The value '' is invalid. 
if (!ModelState.IsValid)
{
    foreach (var k in ModelState.Keys)
    {
        var v = ModelState[k];
        if (v.Errors.Count > 0)
        {
            string s = string.Join(", ", ModelState[k].Errors
                .Select(x => x.ErrorMessage));
            _logger.LogError(k   ": "   s);
        }
    }
    ...

CodePudding user response：

if (!ModelState.IsValid)
{
    var logMessage = string.Join("\n", ModelState.Keys
        .Where(x => ModelState[x].Errors?.Count > 0)
        .Select(x => $"{x}: "   string.Join(", ", ModelState[x].Errors.Select(y => y.ErrorMessage))));
        
    _logger.LogError(logMessage);
}