C# Class with multiple returns string and int

Question

I'm not sure how to describe this, but I'm going to do the best I can. I have a C# app that takes the API of my web app and uses it's JSON response as the data of the app. When a user clicks a button then it pulls the response from the url and parses it so it can be used:

        var client = new WebClient();
        client.Headers.Add("User-Agent", "Nobody");
        var response = client.DownloadString(new Uri("http://localhost:45035/api/products/1"));
        var responsestring = response.ToString();
        JObject o = JObject.Parse(responsestring);

        Int32 Id = (int)o["Id"];
        string Name = (string)o["Name"];
        string Category = (string)o["Category"];
        float Price = (float)o["Price"];
        string Website = (string)o["Website"];

        label1.Text = Name;
        label2.Text = "$" + Price.ToString();
        label3.Text = "Category: " + Category;
        label4.Text = Id.ToString();

That works great. The problem is, when I have thousands of products, this app will have a thousand of code blocks just like this with only the DownloadString Uri changed. I wanted to turn this into one class so I can plug in the appropriate Uri (eg. http://example.com:45035/api/products/1 or http://example.com:45035/api/products/2, etc.) and from that get the Name, Category, Id, etc. from it so my code would be cleaner, but I can not figure out how to do that.

I tried something like:

        public static object responseinfo(string url)
    {
        var client = new WebClient();
        client.Headers.Add("User-Agent", "Nobody");
        var response = client.DownloadString(new Uri(url));
        var responsestring = response.ToString();
        JObject o = JObject.Parse(responsestring);

        Int32 Id = (int)o["Id"];
        string Name = (string)o["Name"];
        string Category = (string)o["Category"];
        float Price = (float)o["Price"];
        string Website = (string)o["Website"];
    }

That allows me to call: jsonfind("http://localhost:45035/api/products/1") but I don't know how to get the strings out so I can use them in the text box like I did before.

I hope that this kind of makes since. It's my first question so if I need to change some, or a lot please tell me.

For the record I am using Json.NET do deal with the JSON responses.

Thanks,

Mitchell

Hi: frankly, I don't understand :(. Q: Your initial code block, ` var client = new WebClient();...`, lives in a C# class, doesn't it? Q: If so, why don't you just make Name, Category, Price and Website members of that class? — paulsm4
– paulsm4, Commented Jul 26, 2012 at 4:52
That code is for a button: Button1_Click. When the button is clicked that first code block is executed. — Mitchell Hoover
– Mitchell Hoover, Commented Jul 26, 2012 at 5:06

Jonathon Reinhart · Accepted Answer · 2012-07-26 05:18:29Z

4

The most direct approach to your question is to use out parameters:

public void GetTwoNumers(out int num1, out int num2) {
    num1 = 4;
    num2 = 2;
}

The better solution would be to pull the WebClient code out into a separate function that returns a JObject:

public static JObject WebRequest(string url) {
    var client = new WebClient();
    client.Headers.Add("User-Agent", "Nobody");
    var response = client.DownloadString(new Uri(url));
    var responsestring = response.ToString();
    return JObject.Parse(responsestring);
}

Then, use that function in a number of other API call functions that each return their own class with the relevant fields:

public class Item {
    public int Id { get; private set; }
    public string Name { get; private set; }
    public string Category { get; private set; }
    public float Price { get; private set; }
    public string Website { get; private set; }

    private Item() {
    }

    public static Item GetFromUrl(string url) {
       var o = WebRequest(url);

        return new Item() {
            Id = (int)o["Id"],
            Name = (string)o["Name"],
            Category = (string)o["Category"],
            Price = (float)o["Price"],
            Website = (string)o["Website"],
        };
    }
}

And then calling this code:

private void button1_Click(object sender, EventArgs e) {
    string url = "...";
    var item = Item.GetFromUrl(url);

    MessageBox.Show("You found item #" + item.Id + " named " + item.Name);

    txtBoxName.Text = item.Name;
    txtBoxCat.Text = item.Category;
}

Note I used a static factory method GetFromUrl here, and made the constructor private. So you can only get an instance via that static method. Not entirely necessary, but a good technique here, IMO.

edited Jul 26, 2012 at 5:18

answered Jul 26, 2012 at 4:48

Jonathon Reinhart

138k38 gold badges266 silver badges347 bronze badges

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

3 Comments

Mitchell Hoover Over a year ago

I think I see what you are saying. Can you give a short example on how you would separate out the functions?

Mitchell Hoover Over a year ago

Sorry for asking so many questions but I am having trouble understanding how I am supposed to use this. Maybe it's because I am frustrated :(. Say user clicks a button: Button1_Click. The button would tell the class where to navigate to, then I need it to return the Id, Name, etc so I can put that into a textbox (eg. textbox1.text = Name, textbox2.text = Category) Does this do that and I just don't see it? Thanks for your help!

Jonathon Reinhart Over a year ago

Added an example of calling the Item.GetFromUrl we just wrote.

Simon Whitehead · Accepted Answer · 2012-07-26 04:51:47Z

I can think of a few options:

1) Create your own type and return it:

class JObjectReturned {
    public int Id { get; set; }
    public string Name { get; set; }
    public string Category { get; set; }
    public float Price { get; set; }
    public string Website { get; set; }
}

public static JObjectReturned responseinfo(string url)
{
    var client = new WebClient();
    client.Headers.Add("User-Agent", "Nobody");
    var response = client.DownloadString(new Uri(url));
    var responsestring = response.ToString();
    JObject o = JObject.Parse(responsestring);

    return new JObjectReturned() { 
        Id = (int)o["Id"],
        Name = (string)o["Name"],
        Category = (string)o["Category"],
        Price = (float)o["Price"],
        Website = (string)o["Website"]
    };
}

Then you can use it like this:

for (int i = 0; i < urls.Length; i++) { 
    JObjectReturned obj = responseInfo(urls[i]);
    // obj.Name, obj.Price, etc..
}

2) Return the JObject.

.. just don't return a Tuple.

Adriaan Stander · Accepted Answer · 2012-07-26 04:51:53Z

0

Have you thought about using a class, lets sa Product, to store and retrieve the values?

puclic class Product
{
   int ID;
   string Name;
   string Category;
   string Website;
   float Price;
}

You could even use a DataTable if you realy wanted to.

answered Jul 26, 2012 at 4:51

Adriaan Stander

167k32 gold badges294 silver badges288 bronze badges

Comments

Andre Calil · Accepted Answer · 2012-07-26 04:54:25Z

Maybe something like this:

public class ProductDTO
{
    public ProductDTO(string SourceURI)
    {
        this.SourceURI = SourceURI;
    }

    public void GetReady()
    {
        var client = new WebClient();
        client.Headers.Add("User-Agent", "Nobody");
        var response = client.DownloadString(new Uri(this.SourceURI));
        var responsestring = response.ToString();
        JObject o = JObject.Parse(responsestring);

        this.Id = (int)o["Id"];
        this.Name = (string)o["Name"];
        this.Category = (string)o["Category"];
        this.Price = (float)o["Price"];
        this.Website = (string)o["Website"];
    }

    public int Id { get; private set; }
    public string Name { get; private set; }
    public string Category { get; private set; }
    public float Price { get; private set; }
    public string Website { get; private set; }
    public string SourceURI { get; private set; }
}

Regards

Collectives™ on Stack Overflow

C# Class with multiple returns string and int

4 Answers 4

3 Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

3 Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related