Build Your Own ASP.NET Website Using C# and VB.NET. Pt. 4. | 3

Build Your Own ASP.NET Website Using C# and VB.NET. Pt. 4.

Processing a Simple Form

Now that you have a basic understanding of ASP.NET page structure, the languages VB.NET and C#, and HTML controls, let’s put everything together and create a simple ASP.NET application . The application that we will create, in VB.NET and C#, will be a simple survey form that uses the following HTML controls:

HtmlForm
HtmlButton
HtmlInputText
HtmlSelect

Let’s begin by creating a new file within your favorite code editor. The following code creates the visual interface for the survey:

Example 4.1. SimpleForm.aspx (excerpt)

<html>
<head>
…
</head>
<body>
<form runat="server">
  <h2>Take the Survey!</h2>
  <p>Name:<br />
  <input type="text" id="txtName" runat="server" /></p>
  <p>Email:<br />
  <input type="text" id="txtEmail" runat="server" /></p>
  <p>Which server technologies do you use?<br />
  <select id="servermodel" runat="server" multiple="true">
    <option>ASP.NET</option>
    <option>PHP</option>
    <option>JSP</option>
    <option>CGI</option>
    <option>Coldfusion</option>
  </select></p>
  <p>Do you like .NET so far?<br />
  <select id="likedotnet" runat="server">
    <option selected>Yes</option>
    <option>No</option>
  </select></p>
  <p><button id="myButton" OnServerClick="Click" runat="server">
  Confirm</button></p>
</form>
</body>
</html>

From what we’ve already covered on HTML controls, you should have a good idea of what this page will look like. All we’ve done is place some HtmlInputText controls , an HtmlButton control , and an HtmlSelect control inside the obligatory HtmlForm control. Remember, HTML controls are essentially just HTML tags with the runat="server" attribute. When it’s complete, the interface will resemble Figure 4.1.

Figure 4.1. Create the interface of the ASP.NET page using HTML controls.

When users click the button, we’ll simply display their responses in their browsers. In a real application, we’d probably be more likely to save this to a database and perhaps show the results as a chart. Whatever the case, we’d access the properties of the HTML controls as shown in the following code:

Example 4.2. SimpleForm.aspx (excerpt)

<script runat="server" language="VB">
Sub Click(s As Object, e As EventArgs)
  Response.Write("Your name is: " & txtName.value & "<br />")
  Response.Write("Your email is: " & txtEmail.value & "<br />")
  Response.Write("You like to work with: " & servermodel.value & _
    "<br />")
  Response.Write("You like .NET: " & likedotnet.value)
End Sub
</script>

Example 4.3. SimpleForm.aspx (excerpt)

<script runat="server" language="C#">
void Click(Object s, EventArgs e) {
  Response.Write("Your name is: " + txtName.Value + "<br />");
  Response.Write("Your email is: " + txtEmail.Value + "<br />");
  Response.Write("You like to work with: " + servermodel.Value +
    "<br />");
  Response.Write("You like .NET: " + likedotnet.Value);
}
</script>

Just as you’ve seen with examples from previous chapters, we place our VB.NET and C# code inside a server-side script block within the <head> part of the page. Next, we create a new Click event handler which takes the two usual parameters. Finally, we use the Response object’s Write() method to print out the user’s responses within the page.

Once you’ve written the code, you can save your work and test the results from your browser. Enter some information and click the button. What you type in should appear at the top of the page when the button is clicked.