构造函数为internal 的public abstract 类能否在程序集外被继承?

Question

internal 访问仅限于当前程序集。internal 关键字是类型和类型成员的访问修饰符。只有在同一程序集的文件中，内部类型或成员才是可访问的，

Answer 1

需要是protected internal
没测试,楼主自己试一下
internal肯定是不行的

Answer 2

这个是SharePoint里的一个类,我就是要继承他,目的是要实现按部门设置权限.
[SharePointPermission(SecurityAction.LinkDemand, ObjectModel=true), SharePointPermission(SecurityAction.InheritanceDemand, ObjectModel=true)]
public abstract class SPPrincipal : SPMember
{
    // Fields
    protected object[,] m_arrMembersData;
    protected bool m_bDataInitialized;
    protected uint m_index;
    internal ISecurableObject m_SecurableObject;
    protected SPWeb m_web;    // Methods
    internal SPPrincipal(SPWeb web, ISecurableObject scope, object[,] arrMembersData, uint index)
    {
        if (web == null)
        {
            throw new ArgumentException();
        }
        this.m_web = web;
        this.m_SecurableObject = scope;
        this.m_index = index;
        this.m_arrMembersData = arrMembersData;
        this.m_bDataInitialized = arrMembersData != null;
    }    protected object GetField(uint fieldIndex)
    {
        if (!this.m_bDataInitialized)
        {
            this.InitMember();
        }
        if (this.m_arrMembersData == null)
        {
            throw new ArgumentException();
        }
        return this.m_arrMembersData[fieldIndex, this.m_index];
    }    protected abstract void InitMember();
    protected void SetField(uint fieldIndex, object value)
    {
        if (!this.m_bDataInitialized)
        {
            this.InitMember();
        }
        if (this.m_arrMembersData == null)
        {
            throw new ArgumentException();
        }
        this.m_arrMembersData[fieldIndex, this.m_index] = value;
    }    // Properties
    public abstract string Name { get; set; }    public SPWeb ParentWeb
    {
        get
        {
            return this.m_web;
        }
    }    private SPRoleDefinitionBindingCollection RoleBindings
    {
        get
        {
            try
            {
                return this.m_web.RoleAssignments.GetAssignmentByPrincipal(this).RoleDefinitionBindings;
            }
            catch (ArgumentException)
            {
                return new SPRoleDefinitionBindingCollection();
            }
        }
    }    [Obsolete("Use the SPRoleAssignment class instead")]
    public SPRoleCollection Roles
    {
        get
        {
            return new SPRoleCollection(this.m_web, this.RoleBindings);
        }
    }
}

Answer 3

子类继承父类，首先要确保父类可以被创造，不管父类有没有internal 构造函数，只要他能在程序集外被创造，它就可以继承类似
namespace one
{
 public abstract class baseclass
{
internal baseclass( )
{
}
public baseclass( int a )
{}
}
}
namespace two
{
  public class childclass:One.baseclass
{
public childclass( int a):base(a)
{}
}
}