无法将类型对象隐式转换为字符串

cannot implicitly convert type object to string

那是因为 MemberList [i] 是一个对象而不是 string 。

That's because MemberList[i] is an object not a string.

protected List<string> FindTargetMember(ArrayList MemberList,String TargetMember)
    {
        List<string> list = new List<string>();
        for (int i = 0; i < MemberList.Count; i++)
        {
            if (TargetMember.Equals(MemberList[i]))
            {
               list.Add(MemberList[i].Name.ToString());
// Assuming Name property is there in MemberList objeect. If it's not you can modify the code by yourself.
            }
        }
        return list;
}

-KR

-KR

由于 ArrayList 是一个对象集合，您必须将项目转换为字符串（您可以只返回输入字符串）。

但请注意：返回找到的项目的索引更有意义（或 -1 是它没有找到。）

Since ArrayList is a collection of objects, you have to cast the item to a string (you could just return the input string).
However, please note: it makes more sense to return the index of the found item (or -1 is it is not found).