Linq - how to convert this code to linq

My Linq-fu is not good enough to translate the following into hopefully one or two lines.

 var errors = new List<string>();
 foreach (var key in ModelState.Keys)
 {
   errors.Add(ModelState[key].Errors.FirstOrDefault().ErrorMessage);
 }

 return Json(new { success = false, errors = erro开发者_Python百科rs });

The closes translation (which is unsafe because FirstOrDefault() could return null in which case your code would throw a null reference exception) would be:

return Json(new { success = false,
                  errors = ModelState.Values
                      .Select(ms => ms.Errors.FirstOrDefault().ErrorMessage)
                      .ToList() });

You could make it a bit safer using:

return Json(new { 
    success = false,
    errors =
        ModelState.Values
                  .Select(ms => 
                          { 
                              var error = ms.Errors.FirstOrDefault();
                              return error == null ? error.ErrorMessage : "";
                          })
                  .ToList() });

The exact translation would be:

var errors = ModelState.Keys.Select(k => ModelState[k].Errors.First().ErrorMessage);
return Json(new { success = false, errors = errors.ToList() });

Provided ModelState is a Dictionary<TKey,TValue> or similar, you could use the values directly:

var errors = ModelState.Values.Select(v => v.Errors.First().ErrorMessage);
return Json(new { success = false, errors = errors.ToList() });

return new Json(new 
   {
      success = false,
      errors = ModelState.Keys.Select(k => ModelState[key].Errors.First().ErrorMessage).ToList()
   });