How can I make a C# class with a constructor and have it return a string?

Question

I created the following:

public class HttpException
{
    public string Text { get; set; }
    public string Message { get; set; }
    public string InnerExceptionMessage { get; set; }
    public string InnerExceptionInnerExceptionMessage { get; set; }
}

I'm calling the class like this:

var e = new HttpException() {
    Text = "City not created",
    Message = ex.Message,
    InnerExceptionMessage = ex.InnerException.Message,
    InnerExceptionInnerExceptionMessage = ex.InnerException.InnerException.Message
};
var jsonMsg = JSON.ToJSONString(e);

Is there a way I could make it so I can call the class with just the parameters of a text message and the exception and then have it return a string jsonMsg

Note that the JSON.ToJSONString(e) is an external class that I am using to form a JSON string.

Why not just override ToString() and use JSON.ToJSONString(e.ToString())? — zzzzBov
– zzzzBov, Commented Jun 22, 2014 at 7:01

Ian Mercer · Accepted Answer · 2014-06-22 07:04:50Z

3

You mean you want a constructor like this?

public class HttpException 
{
    public string Text { get; private set; }
    private readonly Exception ex;
    public string Message { get { return this.ex.message; } }
    public string InnerExceptionMessage { get { return this.ex.... } }
    public string InnerExceptionInnerExceptionMessage { get { return this.ex....} }

    public HttpException(string text, Exception ex)
    {
        this.Text = text;
        this.Exception = ex;
    }
}

I still wouldn't put the JSON code in there though, that's a separate concern and you don't normally want to mix serialization code with regular class code.

answered Jun 22, 2014 at 7:04

Ian Mercer

39.4k8 gold badges104 silver badges139 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Fabio Marcolini · Accepted Answer · 2014-06-22 07:43:01Z

You can use the implicit operator to make implicit cast of the class like this:

    public static void Main()
    {
        HttpException ex = new HttpException ();
        string text = ex;
        Console.WriteLine(text);
        Console.ReadLine();
    }


    public class HttpException 
    {
        public string Text = "goofy";

        public static implicit operator string(HttpException ex)
        {
            return ex.Text;
        }
    }

Remarks:

The implicit operator doesn't stop to string you can make any cast you want.
You can use the explicit operator for doing explicit cast string test = (string)goofy; which might be somewhat more readable.

Cons of using implicit operator:

It's hardly discoverable (It's hard from someone different from yourself to find this "feature" and yourself can forgot about that if you take the code from a month from now.)
It's make the code more complex to read (someone might thing what the hell is going on here).
It's error prone.

Zohar Peled · Accepted Answer · 2014-06-22 07:20:17Z

As mentioned by zzzzBov, you can simply override the ToString() method. However, if the only use for this object is to create the json string, I would consider creating the class like this:

public class HttpException
{
    public string Text { get; set; }
    public string Message { get; set; }
    public string InnerExceptionMessage { get; set; }
    public string InnerExceptionInnerExceptionMessage { get; set; }

    public static string CreateJsonString(string Text, string Message, 
                                          string InnerExceptionMessage, 
                                          string InnerExceptionInnerExceptionMessage) {
        return JSON.ToJSONString(new HttpException() {
                                     Text = "City not created",
                                     Message = ex.Message,
                                     InnerExceptionMessage = ex.InnerException.Message,
                                     InnerExceptionInnerExceptionMessage = 
                                     ex.InnerException.InnerException.Message});
   }
}

then all you have to write in your code is:

var jsonMsg = HttpException.CreateJsonString("City not created", 
                                              ex.Message,
                                              ex.InnerException.Message,
                                              ex.InnerException.InnerException.Message
                                             );

Matías Fidemraizer · Accepted Answer · 2014-06-22 07:31:23Z

0

Implicit operators:

public static implicit operator string(HttpException exception)
{
    return JSON.ToJSONString(e);
}

This implicitly converts an HttpException into a string behind the scenes, so now you can do this:

string json = new HttpException();

answered Jun 22, 2014 at 7:31

Matías Fidemraizer

65.1k19 gold badges132 silver badges217 bronze badges

Collectives™ on Stack Overflow

How can I make a C# class with a constructor and have it return a string?

4 Answers 4

Comments

Remarks:

Cons of using implicit operator:

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

Remarks:

Cons of using implicit operator:

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related