ExpectedException屬性用法

Question

我正在嘗試使用C# UnitTest中的ExpectedException屬性，但我遇到了問題，無法使用我的特定Exception。這是我得到的：

注意：我纏着星號繞着那條給我麻煩的線。

[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捕獲的基本類型Exception。這不應該照顧它嗎？我曾嘗試使用AttributeUsage，但它也沒有幫助。我知道我可以把它包裝在一個try/catch塊中，但是我想看看我能否把這個風格弄清楚。

謝謝大家！

Answer 1

它會失敗，除非異常的類型正是您在屬性 如

PASS指定的類型： -

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

失敗： -

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

然而這將通過...

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