AppDomain.CurrentDomain.BaseDirectory

工作与MbUnit GUI。

据我所知，大多数其他答案都有一些问题。

对于基于磁盘的(而不是基于web的)非gaced程序集，正确的方法是使用当前正在执行的程序集的CodeBase属性。

返回一个URL (file://)。不需要处理字符串操作或UnescapeDataString，可以通过利用Uri的LocalPath属性进行转换。

var codeBaseUrl = Assembly.GetExecutingAssembly().CodeBase;
var filePathToCodeBase = new Uri(codeBaseUrl).LocalPath;
var directoryPath = Path.GetDirectoryName(filePathToCodeBase);

我一直在用汇编。用CodeBase代替Location:

Assembly a;
a = Assembly.GetAssembly(typeof(DaoTests));
string s = a.CodeBase.ToUpper(); // file:///c:/path/name.dll
Assert.AreEqual(true, s.StartsWith("FILE://"), "CodeBase is " + s);
s = s.Substring(7, s.LastIndexOf('/') - 7); // 7 = "file://"
while (s.StartsWith("/")) {
    s = s.Substring(1, s.Length - 1);
}
s = s.Replace("/", "\\");

它一直在工作，但我不再确定它是100%正确的。http://blogs.msdn.com/suzcook/archive/2003/06/26/assembly-codebase-vs-assembly-location.aspx的网页上写着:

"The CodeBase is a URL to the place where the file was found, while the Location is the path where it was actually loaded. For example, if the assembly was downloaded from the internet, its CodeBase may start with "http://", but its Location may start with "C:\". If the file was shadow-copied, the Location would be the path to the copy of the file in the shadow copy dir. It’s also good to know that the CodeBase is not guaranteed to be set for assemblies in the GAC. Location will always be set for assemblies loaded from disk, however."

您可能希望使用CodeBase而不是Location。

我怀疑这里真正的问题是您的测试运行程序将您的程序集复制到不同的位置。在运行时没有办法知道程序集是从哪里复制的，但是您可能可以打开一个开关来告诉测试运行程序集从它所在的位置运行，而不是将它复制到影子目录。

当然，对于每个测试运行者，这样的切换可能是不同的。

您是否考虑过将XML数据作为资源嵌入到测试程序集中?

var assembly = System.Reflection.Assembly.GetExecutingAssembly();
var assemblyPath = assembly.GetFiles()[0].Name;
var assemblyDir = System.IO.Path.GetDirectoryName(assemblyPath);

那么这个呢:

System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location);