Initial setup:
Microsoft Windows XP Professional Version 2002 SP2
Microsoft Development Environment 2003 Version 7.1 (Visual Studio)
Microsoft .NET Framework 1.1 SP1
Microsoft Visual C# .NET

I created a solution containing a Web project and a Class Library project.
The Web project that has a project reference to the Class Library project.

I then installed:
Microsoft Visual Studio 2005 Standard Edition Version 8.0
Microsoft .NET Framework 2.0
Microsoft Visual C# 2005

I used VS2005 to upgrade my solution.

When I debug, I can step into the Web project source code, edit and
continue. I can also step into the Class Library source code. However, when I
try to edit the Class Library source code, I get the following error:

Edit and Continue
Changes are not allowed when the debugger has been attached to an already
running process or the code being debugged is optimized.

The Class Library project Build properties shows Configuration: Debug, and
Optimize code is unchecked

Hi streamline,

Thanks for your post.

Have you tried to create a new project in VS2005 without upgrading? Does
this problem still arise? If so, I suggest you provide some detailed steps
to help me reproduce out this issue. Thanks

Best regards,
Jeffrey Tan
Microsoft Online Partner Support
Get Secure! - www.microsoft.com/security
This posting is provided "as is" with no warranties and confers no rights.

Here are the steps.
Initial setup:

Microsoft Windows XP Professional Version 2002 SP2
Microsoft Visual Studio 2005 Standard Edition Version 8.0
Microsoft .NET Framework 2.0
Microsoft Visual C# 2005

File->New->Web Site
ASP.NET Web Site
OK
File->Add->New Project
Class Library
OK

Add the following code to Class1.cs:

public Class1()
{
            string foo = "bar";

Add the following code to Default.aspx.cs Page_Load:

ClassLibrary1.Class1 obj = new ClassLibrary1.Class1();

Set a breakpoint on that line.
Start debugging.
The following message appears:

Debugging Not Enabled
The page cannot be run in debug mode because debugging is not enabled in the
Web.config file.
What would you like to do?
  [checked] Add a new Web.config file with debugging enabled.
            ! Debugging should be disabled in the Web.config file before
deploying the Web site to a production environment.
[unchecked] Run without debugging. (Equivalent to Ctrl+F5)

I clicked OK (add Web.config).
Web site started running under the ASP.NET Development Server - Port 1129.
(Note that in my real situation I am running under IIS.)
Break point hit.
Step into obj's constructor.
Step to foo assignment.
Attempt to change string.
I get the following error:

Edit and Continue
Changes are not allowed when the debugger has been attached to an already
running process or the code being debugged is optimized.

Note that the default Build properties of ClassLibary1 do not specify
optimized code.

Microsoft Windows XP Professional Version 2002 SP2

Microsoft Visual Studio 2005 Standard Edition Version 8.0

Microsoft .NET Framework 2.0

Microsoft Visual C# 2005

File->New->Web Site

ASP.NET Web Site

OK

File->Add->New Project

Class Library

OK

Add the following code to Class1.cs:

public Class1()

{

            string foo = "bar";

Add the following code to Default.aspx.cs Page_Load:

ClassLibrary1.Class1 obj = new ClassLibrary1.Class1();

Set a breakpoint on that line.

Start debugging.

The following message appears:

Debugging Not Enabled

The page cannot be run in debug mode because debugging is not enabled in the
Web.config file.

What would you like to do?

  [checked] Add a new Web.config file with debugging enabled.

            ! Debugging should be disabled in the Web.config file before
deploying the Web site to a production environment.

[unchecked] Run without debugging. (Equivalent to Ctrl+F5)

I clicked OK (add Web.config).

Web site started running under the ASP.NET Development Server - Port 1129.
(Note that in my real situation I am running under IIS.)

Break point hit.

Step into obj's constructor.

Step to foo assignment.

Attempt to change string.

I get the following error:

Edit and Continue

Changes are not allowed when the debugger has been attached to an already
running process or the code being debugged is optimized.

Note that the default Build properties of ClassLibary1 do not specify
optimized code.

Hi streamline,

Yes, with your detailed steps, I can reproduce out this issue, I will do
some research in this issue, and reply to you ASAP. Thanks

Best regards,
Jeffrey Tan
Microsoft Online Partner Support
Get Secure! - www.microsoft.com/security
This posting is provided "as is" with no warranties and confers no rights.

Hi streamline,

Sorry for letting you wait.

You are correct, Edit and Continue does not work in Web projects(it works
well with console or winform application).  
Actually, this behavior is by design, although I agree that the error
message is not very clear. It turns out that while your code isn¡¯t
¡°Optmized¡±, you did attach to an already running process, because the
debugger automatically attached to the webserver to debug your aspx page.
So the issue regards to the first part of the dialog: "Changes are not
allowed when the debugger has been attached to an already running
process..."

Hope this information helps

Best regards,
Jeffrey Tan
Microsoft Online Partner Support
Get Secure! - www.microsoft.com/security
This posting is provided "as is" with no warranties and confers no rights.

Hi Jeffrey,
This doesn't sound right.
1) The debugger starts the web server.
2) Edit and Continue *does* work in Web projects.
Could you please clarify?

Hi streamline,

Thanks for your feedback.

This is because in VS2005, the web project code is doing dynamically
compiling with Asp.net engine, not the VS2005 IDE(even the code behind is
dynamically compiled). So it is not confined in above VS2005 "Edit and
Continue" limitation.

Hope it will be clarify.

Best regards,
Jeffrey Tan
Microsoft Online Partner Support
Get Secure! - www.microsoft.com/security
This posting is provided "as is" with no warranties and confers no rights.

Hi Jeffrey,
Given that 1) we want Edit and Continue and 2) the bulk of our code is
currently in Class Library projects, what is Microsoft's recommended practice
when upgrading a solution such as ours to Visual Studio 2005?

Thanks

Hi streamline,

For this situation, we have to stop the debug and change the source code in
class library, then re-start the debugging again. This is the behavior of
VS.net2003, which we also have to restart the debugging to let the
modification take effect.

Thanks

Best regards,
Jeffrey Tan
Microsoft Online Partner Support
Get Secure! - www.microsoft.com/security
This posting is provided "as is" with no warranties and confers no rights.