HttpException Constructor ()

 
System_CAPS_noteNote

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Initializes a new instance of the HttpException class and creates an empty HttpException object.

Namespace:   System.Web
Assembly:  System.Web (in System.Web.dll)

public HttpException()

When handling exceptions, it can be useful to capture a series of related exceptions with the outer exception being thrown in response to an inner exception.

A reference to the inner exception that caused the outer exception is available from the InnerException property of the outer exception. This mechanism preserves the error information that is carried by earlier exceptions, including the original exceptions, while allowing you to create more meaningful outer exceptions. For more information, see InnerException.

The following code example demonstrates the HttpException constructor of the HttpException class. The CheckNumber method accepts a user-entered value through a text box and checks whether it is an integer. If the value is not an integer, an exception is thrown, and then a new HttpException object is created and thrown. That exception is caught in the Button_Click event handler and the error message is displayed on the browser.

System_CAPS_security Security Note

This example has a text box that accepts user input, which is a potential security threat. By default, ASP.NET Web pages validate that user input does not include script or HTML elements. For more information, see Script Exploits Overview.


<html xmlns="http://www.w3.org/1999/xhtml" >
   <head>
    <title>
            Example for HttpException
         </title>
<script language="C#" runat="server">
         void CheckNumber()
         {
            try
            {
               // Check whether the value is an integer.
               String convertInt = textbox1.Text;
               Convert.ToInt32(convertInt);
            }
            catch(Exception e)
            {
               // Throw a 'HttpException' object.
               throw new HttpException();
            }
         }

         void Button_Click(Object sender, EventArgs e)
         {
            try
            {
               CheckNumber();
               label1.Text = "The integer value you entered is: "+textbox1.Text;
            }
            catch(HttpException exp)
            {
               label1.Text = "<font color='red'>An HttpException was raised!:"
                  + " The value entered in the textbox is not an integer.</font>";
            }
         }

         void page_load(object sender,EventArgs e)
         {
            label1.Text="";
         }
      </script>
   </head>

   <body>
      <center>
         <h3>
            Example for HttpException
         </h3>
      </center>

      <form id="WebForm9" method="post" runat="server">
         <center>
         <br />
         <b>Enter a value in the text box.</b>
         <br />
         <asp:TextBox Runat="server" ID="textbox1"></asp:TextBox>
         <br />
         <asp:Button Text="Click Here" OnClick="Button_Click" Runat="server"></asp:Button>
         <br />
         <b><asp:Label Runat="server" ID="label1"></asp:Label></b>
         </center>
      </form>
   </body>
</html>

.NET Framework
Available since 1.1
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