如果您在调试构建配置中未选中DLL项目，那么您的新代码将永远无法构建!

转到构建—>配置管理器…(在VS2010中)，并检查您正在尝试调试的代码的项目是否为当前构建配置进行了检查。

VS 2017的一些版本(结合。editorconfig)也有一个问题:从15.3开始，当文件的字符集与.editorconfig (utf8或utf8-bom)中的字符集不一致时，断点就不起作用了。

在某些情况下，重新编译和重新构建并不能帮助克服这个问题。 另一个潜在的解决方案是从解决方案资源管理器中删除带断点的源文件，然后重新添加它(例如通过从文件夹中拖放)。

当调试期间或调试会话之间的系统时间发生变化时，可能会发生这种情况，无论是通过编程方式、手动方式还是通过外部程序。

I suffered from this recently, and in my case I traced the problem back to something I was doing when testing: changing the system time. I'm not suggesting this is the case for everyone, but thought I'd mention it since it hasn't been mentioned already. It appears if you start moving the clock around between debug builds then it can get very confused about what order various files have been created it - I can only assume it is using file modified dates to determine if the source code is valid or not, and which binaries it needs to recompile.

这也是一个重新保存网页的选项。配置以碰撞其修改时间。

在我的例子中，我忘记在我声明模板函数的头文件中包含“stdafx.h”。