Handling Asp.net Errors C#

Question

In my project I have a custom error solution. In the controller I do a try/catch and handle the exception with a popup instead of using the forms method. I can handle all of the errors correctly that are specified in the Model as the error, however I am unable to get a proper error coming from a AddError result. This is what I use:

System.Text.StringBuilder sb = new System.Text.StringBuilder();

And then I put return content(sb.ToString()); This will either show that it was successful or not. If there is an error I use this:

     foreach (var key in this.ViewData.ModelState.Keys)
     {
       foreach (var err in this.ViewData.ModelState[key].Errors)
       {
           sb.Append(err.ErrorMessage + "<br/>");
       }
     }

And of course the Exception of the try/catch would be:

 catch (Exception ex)
 {
    sb.Append("Error :" + ex.Message);
 }

My question is how do I implement the AddErrors from context to this. I have tried sb.Append(result); and sb.Append(result.Errors); I only see the actual error in my locals window under Error. I would like them to show up in the popup. By the way this is for a registration form. The registration form normally just has AddErrors(result);

Thanks for your help.

UPDATE: Added AddErrors

  private void AddErrors(IdentityResult result)
    {
        foreach (var error in result.Errors)
        {
            ModelState.AddModelError("", error);
        }
    }

Answer 1

Because result is a type of IdentityResult but StringBuilder.Append might need to pass string value in that, so if we want to use StringBuilder.Append to append information that needs to convert as a string.

one way we can try to let result object deserialize as a JSON string value.

We can use JsonConvert.SerializeObject which is created by Json.NET

StringBuilder.Append(JsonConvert.SerializeObject(result.Errors));