NUnit的TestCaseAttribute可以简化大量的测试参数输入用例的编写，如果基于Visual Studio Unit Test Project开发则默认没有类似的功能，看一段对比代码：
public class MyClass{ public Int32 DoWork(String name, Int32 n) { if (String.IsNullOrWhiteSpace(name)) throw new ArgumentOutOfRangeException("name"); if (n < 0) throw new ArgumentOutOfRangeException("n"); return name.Length / n; }} [TestClass]public class MyClassTest{ [TestMethod] public void DoWork() { var name = "test"; var n = 5; var myClass = new MyClass(); var result = myClass.DoWork(name, n); Assert.IsTrue(result == name.Length / n); } [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))] public void DoWork_NameIsNull() { var n = 5; var myClass = new MyClass(); myClass.DoWork(null, n); } [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))] public void DoWork_NameIsEmpty() { var n = 5; var myClass = new MyClass(); myClass.DoWork(String.Empty, n); } [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))] public void DoWork_NameIsWhiteSpace() { var n = 5; var myClass = new MyClass(); myClass.DoWork(" ", n); } [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))] public void DoWork_NLessThanZero() { var name = "test"; var myClass = new MyClass(); myClass.DoWork(name, -1); }} 可以发现为了测试参数输入验证是否达到预期的效果，额外编写了4个测试用例。如果使用NUnit的TestCase可以简化如下：
[TestFixture]public class MyClassTest{ [TestCase("Test", 5)] [TestCase(null, 5, ExpectedException = typeof(ArgumentOutOfRangeException))] [TestCase("", 5, ExpectedException = typeof(ArgumentOutOfRangeException))] [TestCase(" ", 5, ExpectedException = typeof(ArgumentOutOfRangeException))] [TestCase("Test", -1, ExpectedException = typeof(ArgumentOutOfRangeException))] public void DoWork(String name, Int32 n) { var myClass = new MyClass(); var result = myClass.DoWork(name, n); Assert.IsTrue(result == name.Length / n); }} 要让Visual Studio Test支持类似的方式可以自己扩展，参考Visual Studio Team Test的文章。不过我选择了更为简单的在原有的用例中扩展一个TestMethodCaseAttribute，例如：
[TestClass]public class MyClassTest{ [TestMethod] [TestMethodCase("Test", 5)] [TestMethodCase(null, 5, ExpectedException = typeof(ArgumentOutOfRangeException))] [TestMethodCase("", 5, ExpectedException = typeof(ArgumentOutOfRangeException))] [TestMethodCase(" ", 5, ExpectedException = typeof(ArgumentOutOfRangeException))] [TestMethodCase("Test", -1, ExpectedException = typeof(ArgumentOutOfRangeException))] public void DoWork() { TestMethodCaseHelper.Run(context => { var name = context.GetArgument (0); var n = context.GetArgument (1); var myClass = new MyClass(); var result = myClass.DoWork(name, n); Assert.IsTrue(result == name.Length / n); }); }} 只要有一个TestMethodCase未通过，当前的TestMethod既为失败。使用这种方式进行Code Coverage统计并不受影响，可以正确评估
public static class TestMethodCaseHelper{ public static void Run(Action body) { var testMethodCases = FindTestMethodCaseByCallingContext(); foreach (var testMethodCase in testMethodCases) RunTest(testMethodCase, body); } internal static IEnumerable FindTestMethodCaseByCallingContext() { var stackFrames = StackFrameHelper.GetCurrentCallStack(); var forTestFrame = stackFrames.FirstOrDefault(p => GetTestMethodCaseAttributes(p).Any()); return forTestFrame != null ? GetTestMethodCaseAttributes(forTestFrame) : new TestMethodCaseAttribute[0]; } private static IEnumerable GetTestMethodCaseAttributes(StackFrame stackFrame) { return GetTestMethodCaseAttributes(stackFrame.GetMethod()); } private static IEnumerable GetTestMethodCaseAttributes(MethodBase method) { return method.GetCustomAttributes(typeof(TestMethodCaseAttribute), true).OfType (); } private static void RunTest(TestMethodCaseAttribute testMethodCase, Action body) { TestSettings.Output.WriteLine("Run TestMethodCase {0} started", testMethodCase.Name); var stopwatch = Stopwatch.StartNew(); RunTestCore(testMethodCase, body); stopwatch.Stop(); TestSettings.Output.WriteLine("Run TestMethodCase {0} finished({1})", testMethodCase.Name, stopwatch.ElapsedMilliseconds); } private static void RunTestCore(TestMethodCaseAttribute testMethodCase, Action body) { var testContext = new TestMethodCaseContext(testMethodCase); if (testMethodCase.ExpectedException != null) RunTestWithExpectedException(testMethodCase.ExpectedException, () => body(testContext)); else body(testContext); } private static void RunTestWithExpectedException(Type expectedExceptionType, Action body) { try { body(); } catch (Exception ex) { if (ex.GetType() == expectedExceptionType) return; throw; } }} [AttributeUsage(AttributeTargets.Method, AllowMultiple = true)]public sealed class TestMethodCaseAttribute : Attribute{ public TestMethodCaseAttribute(params Object[] arguments) { this.Arguments = arguments; } public String Name { get; set; } public Type ExpectedException { get; set; } public Object[] Arguments { get; private set; }} [AttributeUsage(AttributeTargets.Method, AllowMultiple = true)]public sealed class TestMethodCaseAttribute : Attribute{ public TestMethodCaseAttribute(params Object[] arguments) { this.Arguments = arguments; } public String Name { get; set; } public Type ExpectedException { get; set; } public Object[] Arguments { get; private set; }} public class TestMethodCaseContext{ private readonly TestMethodCaseAttribute _testMethodCase; internal TestMethodCaseContext(TestMethodCaseAttribute testMethodCase) { _testMethodCase = testMethodCase; } public T GetArgument (Int32 index) { return (T)_testMethodCase.Arguments.ElementAtOrDefault(index); }} internal static class StackFrameHelper{ public static IEnumerable GetCurrentCallStack() { var frameIndex = 0; while (true) { var stackFrame = new StackFrame(frameIndex, false); if (stackFrame.GetILOffset() == StackFrame.OFFSET_UNKNOWN) break; yield return stackFrame; ++frameIndex; } }}