我发现我的解足够检索位置。

var executingAssembly = new FileInfo((Assembly.GetExecutingAssembly().Location)).Directory.FullName;

我在过去的NUnit中得到了相同的行为。默认情况下，NUnit将程序集复制到临时目录。你可以在NUnit设置中改变这种行为:

也许TestDriven。NET和MbUnit GUI有相同的设置。

Web应用程序?

Server.MapPath("~/MyDir/MyFile.ext")

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?

string path = Path.GetDirectoryName(typeof(DaoTests).Module.FullyQualifiedName);

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。