Error handling is one of the most important (and maybe least enjoying) things to do while developing.

Most of the times error-prone methods will contain try/catch blocks to prevent the exception from slipping through. There might still be some unhandled exceptions though, in code blocks not "protected" by a try/catch block. Those can be handled on page or on application level.

Now let's see an example, writing the error to the trace (so it can be viewed and further investigated by a developer using a trace listener) in case of page level error handling and navigating to a user defined error page in case of application level exception handling.

On page level :

    protected void Page_Error(object sender, EventArgs e)
    {
        // Retrieve the last error and write to the trace
        Trace.Write(Server.GetLastError());
        // Clear the last error
        Server.ClearError();
    }

On application level :

    void Application_Error(object sender, EventArgs e)
    {
        // Navigate to a user defined error page
        Server.Transfer("HandleError.aspx");
        // Make sure to call Server.GetLastError() and Server.ClearError() in the error handling page
    }

11-08-2007 om 23:19 geschreven door Reinout Waelput  

There are different ways to navigate to a different URL, including :
Response.Redirect(“url”);
Server.Transfer(“url”, false); 

What's the difference?
With Response.Redirect you will not be able to access data from the original page through the PreviousPage property, by using Server.Transfer (or the PostBackUrl property) you will be able to do so.

11-08-2007 om 23:02 geschreven door Reinout Waelput  

11-08-2007 om 21:14 geschreven door Reinout Waelput  

11-08-2007 om 20:33 geschreven door Reinout Waelput