你可以用两种方法对私有方法进行单元测试

you can create instance of PrivateObject class the syntax is as follows PrivateObject obj= new PrivateObject(PrivateClass); //now with this obj you can call the private method of PrivateCalss. obj.PrivateMethod("Parameters"); You can use reflection. PrivateClass obj = new PrivateClass(); // Class containing private obj Type t = typeof(PrivateClass); var x = t.InvokeMember("PrivateFunc", BindingFlags.InvokeMethod | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance, null, obj, new object[] { 5 });

CC -Dprivate=public

“CC”是我使用的系统上的命令行编译器。-Dfoo=bar相当于#define foo bar。因此，这个编译选项有效地将所有私有内容更改为公共。

一种方法是保护您的方法，并编写一个继承要测试的类的测试fixture。这样，您既没有将方法公开，但是启用了测试。

在极少数情况下，我想要测试私有函数，我通常会将它们修改为受保护的，并且我已经编写了一个带有公共包装器函数的子类。

类:

...

protected void APrivateFunction()
{
    ...
}

...

测试子类:

...

[Test]
public void TestAPrivateFunction()
{
    APrivateFunction();
    //or whatever testing code you want here
}

...

I don't agree with the "you should only be interested in testing the external interface" philosophy. It's a bit like saying that a car repair shop should only have tests to see if the wheels turn. Yes, ultimately I'm interested in the external behavior but I like my own, private, internal tests to be a bit more specific and to the point. Yes, if I refactor, I may have to change some of the tests, but unless it's a massive refactor, I'll only have to change a few and the fact that the other (unchanged) internal tests still work is a great indicator that the refactoring has been successful.

You can try to cover all internal cases using only the public interface and theoretically it's possible to test every internal method (or at least every one that matters) entirely by using the public interface but you may have to end up standing on your head to achieve this and the connection between the test cases being run through the public interface and the internal portion of the solution they're designed to test may be difficult or impossible to discern. Having pointed, individual tests that guarantee that the internal machinery is working properly is well worth the minor test changes that come about with refactoring - at least that's been my experience. If you have to make huge changes to your tests for every refactoring, then maybe this doesn't make sense, but in that case, maybe you ought to rethink your design entirely. A good design should be flexible enough to allow for most changes without massive redesigns.

您可以在Visual studio 2008中为私有方法生成测试方法。当您为私有方法创建单元测试时，test References文件夹将添加到测试项目中，访问器将添加到该文件夹中。存取器也在单元测试方法的逻辑中被引用。这个访问器允许单元测试调用正在测试的代码中的私有方法。 详情请看

http://msdn.microsoft.com/en-us/library/bb385974.aspx