c# - ExpectedException 属性用法

Question

我正在尝试使用 a 中的ExpectedException属性C# UnitTest，但在使其与我的特定Exception. 这是我得到的：

注意：我在给我带来麻烦的行周围加上了星号。

    [ExpectedException(typeof(Exception))]
    public void TestSetCellContentsTwo()
    {
        // Create a new Spreadsheet instance for this test:
        SpreadSheet = new Spreadsheet();

        // If name is null then an InvalidNameException should be thrown. Assert that the correct 
        // exception was thrown.
        ReturnVal = SpreadSheet.SetCellContents(null, "String Text");
        **Assert.IsTrue(ReturnVal is InvalidNameException);**

        // If text is null then an ArgumentNullException should be thrown. Assert that the correct
        // exception was thrown.
        ReturnVal = SpreadSheet.SetCellContents("A1", (String) null);
        Assert.IsTrue(ReturnVal is ArgumentNullException);

        // If name is invalid then an InvalidNameException should be thrown. Assert that the correct 
        // exception was thrown.
        {
            ReturnVal = SpreadSheet.SetCellContents("25", "String Text");
            Assert.IsTrue(ReturnVal is InvalidNameException);

            ReturnVal = SpreadSheet.SetCellContents("2x", "String Text");
            Assert.IsTrue(ReturnVal is InvalidNameException);

            ReturnVal = SpreadSheet.SetCellContents("&", "String Text");
            Assert.IsTrue(ReturnVal is InvalidNameException);
        }
    }

我有ExpectedException捕捉基本类型Exception。这不应该管吗？我试过使用AttributeUsage，但它也没有帮助。我知道我可以将它包装在一个 try/catch 块中，但我想看看我是否能弄清楚这种风格。

谢谢大家！

Answer 1

除非异常的类型完全是您在属性中指定的类型，否则它将失败，例如

经过：-

    [TestMethod()]
    [ExpectedException(typeof(System.DivideByZeroException))]
    public void DivideTest()
    {
        int numerator = 4;
        int denominator = 0;
        int actual = numerator / denominator;
    }

失败：-

    [TestMethod()]
    [ExpectedException(typeof(System.Exception))]
    public void DivideTest()
    {
        int numerator = 4;
        int denominator = 0;
        int actual = numerator / denominator;
    }

不过这会过去...

    [TestMethod()]
    [ExpectedException(typeof(System.Exception), AllowDerivedTypes=true)]
    public void DivideTest()
    {
        int numerator = 4;
        int denominator = 0;
        int actual = numerator / denominator;
    }