Debugging in ASP.NET

Debugging is the process of finding and correcting the errors in a program. In normal Active Server Pages (ASP) file Response.Write statement was the only primary method to debug the errors and even Script Debugger was not sophisticated to debug, in comparison to the debuggers that Windows developers had for Visual Basic and C++ code. All these deficiencies have been changed in .Net Framework because the Common Language Runtime provides integrated debugging for all the applications. The primary objectives for debugging in ASP.NET include both in-process and out-of-process debugging, remote process debugging, managed and unmanaged code debugging, edit and continue, and mixed language support.

You can enable debugging in ASP.NET page by writing the <%@Page debug=”True” %> page directive at the top of the page. This statement asks the compiler to exclude debugging symbols into the compiled page, and allows the debugger to attach to the running program. But before using the debugger, you should also need to view the web page in the browser so that the debugging symbols are loaded for the page.

The SDK debugger that comes along with .NET SDK can be found in the GuiDebug directory. This debugger has all the features such as viewing contents of variables, setting breakpoints on specific exceptions, expressions, or specific lines, stepping into, out of, and over code, and viewing the call stack, threads and modules as that of Visual Studio debugger except that SDK debugger does not support remote debugging or Edit and Continue features. Therefore it can be presumed that SDK debugger is a read-only debugger that does not allow you to edit code inline. You can just edit the code externally and to view the new changes made in the application you have to rerun the application.

Just-In-Time debugging is another technique to debug a program that is started outside of Visual Studio. If you have enabled Just-In-Time debugging, you can view a dialog box when a crash occurs.