为什么通过构造函数在List<T>中向ApplicationSettingsBase中添加自定义对象不起作用？

Question

这与another SO question.密切相关。

使用下面的示例，有人能向我解释为什么添加一个新的List<Foo> (其中每个Foo的属性都是显式设置的)导致ApplicationSettingsBase.Save()方法正确地存储数据，而通过构造函数(构造函数设置属性值)向列表中添加一个新Foo不起作用吗？谢谢!

public class Foo
{
    public Foo(string blah, string doh)
    {
        this.Blah = blah;
        this.Doh = doh;
    }

    public Foo() { }

    public string Blah { get; set; }
    public string Doh { get; set; }
}

public sealed class MySettings : ApplicationSettingsBase
{
    [UserScopedSetting]
    public List<Foo> MyFoos
    {
        get { return (List<Foo>)this["MyFoos"]; }
        set { this["MyFoos"] = value; }
    }
}

// Here's the question...
private void button1_Click(object sender, EventArgs e)
{
    MySettings mySettings = new MySettings();

    // Adding new Foo's to the list using this block of code doesn't work.
    List<Foo> theList = new List<Foo>()
    { 
        new Foo("doesn't","work")
    };

    // But using this block of code DOES work.
    List<Foo> theList = new List<Foo>()
    { 
        new Foo() {Blah = "DOES", Doh = "work"}
    };

   // NOTE: I never ran both the above code blocks simultaneously. I commented
   // one or the other out each time I ran the code so that `theList` was 
   // only created once.

    mySettings.MyFoos = theList;
    mySettings.Save();
}

Answer 1

我刚才在试图澄清我的问题时偶然发现了答案。如果我向Foo类提供默认构造函数：

public Foo() { }

--其他一切保持不变--然后在执行user.config文件时，类的值将正确地存储在ApplicationSettingsBase.Save()文件中。真奇怪。

Answer 2

这可能是由于您如何构建您的示例。但是，使用给定的代码，“不工作”列表在执行“确实工作”部分时将被删除。如果希望两个元素都在方法末尾的theList中，则只能有一个new List<Foo>()调用。