When debugging ASP.NET MVC app, breakpoints are no

问题:

When trying to debug a ASP.NET MVC app, the breakpoints in my controllers arent getting hit. When entering debug mode they just show an empty red circle with a warning triangle instead of the normal full circle. This is strange because debugging was working fine until now, and no configuration changes have been made in my environment for a while.

I have seen this question and had a look at my modules view and the correct ones aren't being loaded, however I'm not sure how to remedy this. Also all the relevant pdb files are in the bin folder of the site.

Any suggestions on how to fix this?

Cheers!

EDIT: The app is running as a local site on IIS7 and I'm debugging with VS 2008

回答1:

Ok so after 4 hours wasted, I find that setting my web project as the startup project solves the issue! This surely must be a bug...

I hope I save someone out there half a day :)

回答2:

Few more possibilities:

• If you have a client and server in your solution (lets say a WPF and WCF app) you should make sure you select 'multiple startup projects'. [this one is similar to your accepted answer, but useful if you need a client running too]

• Release mode is selected for the project. When doing a fresh get (as I discovered today) on a new machine VS seems to like to switch to 'Release' configuration profile.

回答3:

Some team member deleted the Debug configuration for one project (The MVC Project). Though the Solution configuration was set to "Debug / AnyCPU", if you looked in the configuration for that, the Project-Configuration for the MVC Project was set to Release, with no option for Debug, and all other projects were set as Debug appropriately.

So I added Debug back to the project configurations (Just drop-down "Add"... uncheck the box to add to solution). And viola...

回答4:

None of these answers helped me. Some of my breakpoints were hit, and some not. But I discovered the problem in my case.

If there is a file at the exact same virtual location with the exact same name as the URL you are trying to debug, the file will be served to the browser automatically by IIS and the breakpoint will not be hit because no MVC code actually runs.

回答5:

Things to try:

1. Clean the Solution, then rebuild it.

2. If that doesn't work, close the solution, delete the bin and obj folders, and rebuild.

3. If that doesn't work, restart the IDE after doing step #2.
4. If you're debugging an ASP.NET project hosted by IIS, make sure you're attached to the correct process (w3wp.exe).

回答6:

The following has worked for me most of the time when I had this problem:

Find where your projects dll cache is being held (usually in ASP.NET Temprorary Files). Then close VS, do an IISRESET /stop (if you're using IIS), delete all the files in dll cache. Do an IISRESET, start VS, open your project and rebuild it.

回答7:

I had the same problem. Check here: Tools->Options->Debugging

Fix by selecting Enable .Net Framework source stepping

回答8:

Change in Visual Studio Header Release option to Debug

回答9:

I had the same problem. Check here: Tools->Options->Debugging

Check the script check box. Run the application.

I got installation corrupt message box, so did a repair of vs 2008, and its working now.

回答10:

I had this problem today - then found out that it happened because:

1. Visual Studio 2008 had crashed, leaving Cassini (the intrinsic development web server) running on the original port.

2. When I reopened my project and "Started" it, it couldnt run on the original port because the old development web server was still running (which I didnt notice)

3. The pages browsed fine, but no breakpoints got hit because the URL I was using was still pointing to the old development web server port.

回答11:

Clean / rebuild didn't work for me. Restarting VS did.

VS 2012, ASP.NET MVC 3, IIS Express.

回答12:

Make sure that your compilation framework version is the same as your project's compilation framework.. I ran into this and it was because the project was being compiled as 4.5 and the compilation attrib in the web config was trying to debug it as 4.5.1.

回答13:

It might be helpful to:

1. Close Visual Studio
2. Stop application pool in IIS Manager
3. Delete bin and obj folder
4. Start appliction pool
5. Open Visual Studio and rebuild solution

回答14:

I had a similar problem with a simple Web API project in Visual Studio 2015. I solved the problem, after reading that the easy fix was to set the Startup Project to the correct project. Since I had another Web API project in the same solution, I guessed that the project I was debugging was mixing up which index.html to debug, so I renamed that current one to index2.html. Then setting the Project properties Web tab to Specific Page and the page text: "index2.html" solved the problem.

回答15:

My solution was basically my mistake because I had moved the project folder. My resolution was, after I moved the folder, do NOT use "Open...Open website" and then browse to your website folder. DO NOT browse to your solution .sln file and open with that. Instead, DO USE "Open...Project/Solution" then browse to your csproj file and open that. Close IIS(Express) first. Rebuild. It should run the latest copy. The .sln will screw you up every time.

回答16:

I had Shelved my changes in TFS and had a breakpoint set on a shelved cs file that was not part of the solution anymore. Once I retrieved my Shelveset, everything worked.