无法转换类型为"object {System.Collections.Generic.List< string []>}}"的对象；作为ICollection< object> [英] Unable to cast an object of type "object {System.Collections.Generic.List<string[]>}" as ICollection<object>

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为什么不能在运行时将类型为 object {System.Collections.Generic.List< string []>} 类型的对象转换为 ICollection< object> >?

Why can you not cast a object which at runtime has type object {System.Collections.Generic.List<string[]>} as an ICollection<object>?

我确定它很明显，但是我无法弄清楚.

I'm sure its something obvious but I cant figure it out.

它给出了例外-

无法转换类型的对象键入"System.Collections.Generic.List 1 [System.String []]"'System.Collections.Generic.ICollection 1 [System.Object]'.

Unable to cast object of type 'System.Collections.Generic.List1[System.String[]]' to type 'System.Collections.Generic.ICollection1[System.Object]'.

在C#4.0之前，泛型不是协变的.如果您不使用C#4.0，则可以像这样完成转换:

Before C# 4.0, generics are not covariant. If you are not using C# 4.0, you can accomplish this cast like this:

List<string[]> list = new List<string[]>();
//...Fill the list...
ICollection<object> collection = list.ConvertAll<object>(item => item as object);

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无法转换类型为"object {System.Collections.Generic.List&lt; string []&gt;}}"的对象；作为ICollection&lt; object&gt; [英] Unable to cast an object of type &quot;object {System.Collections.Generic.List&lt;string[]&gt;}&quot; as ICollection&lt;object&gt;