Solved

c#, ignore the error in catch (as in try catch)

Posted on 2014-11-15
3
160 Views
Last Modified: 2014-11-15
In a list box, when I click on an item, this code puts the selected item on the screen. One of the items reads <All> which put the program in panic and produces the error below:

Question: How can I find the error number for this instance and pacify the error?
try
{
   Response.Write(lstCity.SelectedItem.Text); 
}
  catch (Exception ex)
{
  // *********find the error number when lstCity.SelectedItem.Text == <All> and pacify the error
}

Open in new window

Error message when <All> is selected:
Server Error in '/' Application.

A potentially dangerous Request.Form value was detected from the client (lstCity="<All>").

Description: ASP.NET has detected data in the request that is potentially dangerous because it might include HTML markup or script. The data might represent an attempt to compromise the security of your application, such as a cross-site scripting attack. If this type of input is appropriate in your application, you can include code in a web page to explicitly allow it. For more information, see http://go.microsoft.com/fwlink/?LinkID=212874. 

Exception Details: System.Web.HttpRequestValidationException: A potentially dangerous Request.Form value was detected from the client (lstCity="<All>").

Source Error: 


[No relevant source lines]

Source File: c:\Users\Mike\AppData\Local\Temp\Temporary ASP.NET Files\vs\0db659aa\1e56896f\App_Web_1ohlj355.0.cs    Line: 0 

Stack Trace: 


[HttpRequestValidationException (0x80004005): A potentially dangerous Request.Form value was detected from the client (lstCity="<All>").]
   System.Web.HttpRequest.ValidateString(String value, String collectionKey, RequestValidationSource requestCollection) +9693725
   System.Web.<>c__DisplayClass5.<ValidateHttpValueCollection>b__3(String key, String value) +18
   System.Web.HttpValueCollection.EnsureKeyValidated(String key) +9693093
   System.Web.HttpValueCollection.GetValues(String name) +17
   System.Web.UI.WebControls.ListBox.LoadPostData(String postDataKey, NameValueCollection postCollection) +51
   System.Web.UI.WebControls.ListBox.System.Web.UI.IPostBackDataHandler.LoadPostData(String postDataKey, NameValueCollection postCollection) +15
   System.Web.UI.Page.ProcessPostData(NameValueCollection postData, Boolean fBeforeLoad) +303
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +6704
   System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +245
   System.Web.UI.Page.ProcessRequest() +72
   System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) +21
   System.Web.UI.Page.ProcessRequest(HttpContext context) +58
   ASP.default_aspx.ProcessRequest(HttpContext context) in c:\Users\Mike\AppData\Local\Temp\Temporary ASP.NET Files\vs\0db659aa\1e56896f\App_Web_1ohlj355.0.cs:0
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +341
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +69

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.34237

Open in new window

0
Comment
Question by:Mike Eghtebas
3 Comments
 
LVL 32

Accepted Solution

by:
it_saige earned 400 total points
ID: 40444879
You could rewrite it like this:
try
{
	Response.Write(lstCity.SelectedItem.Text); 
}
catch (HttpRequestValidationException ex)
{
	if (ex.Message.Contains("lstCity = <All>"))
		Response.Write(lstCity.SelectedItem.Text);
	else
	{
		// This is really an exception, do some logging
	}
}
catch (Exception ex)
{
	// Do something logging.
}

Open in new window


But I would recommend that you choose a different item to represent <ALL>, like -ALL-, or just All Cities.

-saige-
0
 
LVL 35

Assisted Solution

by:Miguel Oz
Miguel Oz earned 100 total points
ID: 40444892
AS suggested by Saige you need a different string to represent <ALL>, this string  is not valid because it contains "<" and ">" .
0
 
LVL 33

Author Closing Comment

by:Mike Eghtebas
ID: 40444902
I used -All-
0

Featured Post

Top 6 Sources for Identifying Threat Actor TTPs

Understanding your enemy is essential. These six sources will help you identify the most popular threat actor tactics, techniques, and procedures (TTPs).

Join & Write a Comment

Introduction Although it is an old technology, serial ports are still being used by many hardware manufacturers. If you develop applications in C#, Microsoft .NET framework has SerialPort class to communicate with the serial ports.  I needed to…
Summary: Persistence is the capability of an application to store the state of objects and recover it when necessary. This article compares the two common types of serialization in aspects of data access, readability, and runtime cost. A ready-to…
It is a freely distributed piece of software for such tasks as photo retouching, image composition and image authoring. It works on many operating systems, in many languages.
Access reports are powerful and flexible. Learn how to create a query and then a grouped report using the wizard. Modify the report design after the wizard is done to make it look better. There will be another video to explain how to put the final p…

708 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

13 Experts available now in Live!

Get 1:1 Help Now