Using web service in Csharp October 23, 2012

In this tutorial, I'll show you how to create a web service in c# and call it with webform and winform applications.

1. Create web service:
+) Open MS Visual Studio: File > New > Web Site

Choose ASP.NET Web Service

This's default service after created.

[WebMethod]
    public string HelloWorld() {
        return "Hello World";
    }

+) Add new service under (for example add a sum function):

[WebMethod]
    public int Sum(int a, int b)
    {
        return a + b;
    }

+) And now click Start Debugging, you can see a webpage like this.

Done Step 1!

2: Call web service from .aspx website.
+) Keep web service running
+) Create new ASP.Net Web Site

Choose ASP.NET Web Site

+) Design Default.aspx page like:

2 TextBox, 1 Button, 1 Label

+) Add web service referent: Choose from menu: Website > Add Web Reference

• Url: Paste your web service link from Step 1 > Press GO
• Web reference name: [Your reference name] > Press Add Reference

+) Double click into Button on page to make Button1_Click() function automatically and add code:

protected void Button1_Click(object sender, EventArgs e)
    {
        // Get object and convert to int32
        int a = Convert.ToInt32(TextBox1.Text);
        int b = Convert.ToInt32(TextBox2.Text);
        // Define web service
        demowebservice.Service mySv = new demowebservice.Service();
        // Calculation
        int result = mySv.Sum(a, b);
        // Show result
        Label1.Text = "Result: " + result.ToString();
    }

+) Click run the website and done!

Note: Keep web service running when testing.

3. Call web service from winform:
+) Create new window form with same design like:

+) Add Service reference: On menu Project > Add Service Reference

• Address: Link to web service > Click GO
• Namespace: Name of service reference

+) Add code into button1_Click():

private void button1_Click(object sender, EventArgs e)
        {
            // Get object and convert to Int32
            int a = Convert.ToInt32(textBox1.Text);
            int b = Convert.ToInt32(textBox2.Text);
            // Define web service
            ServiceReference1.ServiceSoapClient service = new ServiceReference1.ServiceSoapClient();
            // Calculation
            int result = service.Sum(a, b);
            // Show result
            label1.Text = "Result: " + result.ToString();
        }

+) Run app and enjoy: