Using a Web Service - Page 4

In the previous page, you added a reference to a web service. A reference by itself isn't all that helpful. We need to use the reference to do some cool(er) things, and this page will show you how.

Interacting with the Web Service using Code
We are finally at the stage where we can use some code to interact with our newly created web service. Before I go through explaining how to get our application to work, allow me to briefly summarize how you would use code to refer to your newly added web service.

In order to use the web service, you will need to assign a variable to it. Your variable will be of a type determined by both your web service Reference name as well as your Web Service's class name. Don't worry though, the auto-complete feature of Visual Studio makes it very easy.

In our case, our Web Reference is called MovieService. So typing MovieService followed by  the dot ( . ) provides us with the following drop-down menu:

Automatically, the TopMovies item is selected, because that is a high-probability choice that you will make in this situation. So, our variable will be of type MovieService.TopMovies:

MovieService.TopMovies foo = new MovieService.TopMovies();

The foo variable in the above case can access all of the methods from the TopMovies.asmx web service you added under the MovieService reference. You will see more of this as we get back into finishing up our program.

Getting back to our application, our code will be added to the Default.aspx file's code-behind file. Open the Default.aspx.cs file by expanding your Default.aspx file (if it isn't already expanded already) and double-click on Default.aspx.cs:

Once you have opened the Default.aspx.cs file, with the exception of the using statements, your code is pretty much empty. Copy and paste the following lines of code into the  MovieInfo_Default code block:

MovieService.TopMovies ws; protected void Page_Load(object sender, EventArgs e) { Page.RegisterHiddenField("__EVENTTARGET", "btnInput"); ws = new MovieService.TopMovies(); } protected void btnInput_Click(object sender, EventArgs e) { lblResult.Text = ws.GetMovieAtNumber(Convert.ToInt32(txtInput.Text)); }

The above code assumes you have a button called btnInput, a text input field called txtInput, and a label component called lblResult defined in the design of Default.aspx. If you followed Part 1 of this tutorial, then you do, so don't worry about it.

If you were to preview your page, you will find that your example works just as well as the example I have posted on the first page: http://www.kirupafx.com/MovieInfo/Default.aspx

Now you are done re-creating the example I posted on my home page. But beyond dragging/dropping and copying/pasting code, we really haven't done much. In the next page, we will take a look at why the code works so that you can learn how to apply modified versions of what was explained in this tutorial in your own applications.

Onwards to the next page!

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