保護內部

protected internal 關鍵字標記在同一個程式集或另一個程式集中的派生類中使用的欄位，方法，屬性和巢狀類：

大會 1

public class Foo
{
    public string MyPublicProperty { get; set; }
    protected internal string MyProtectedInternalProperty  { get; set; }

    protected internal class MyProtectedInternalNestedClass
    {
        private string blah;
        public int N { get; set; }
    }
}

public class Bar
{
    void MyMethod1()
    {
        Foo foo = new Foo();
        var myPublicProperty = foo.MyPublicProperty;
        var myProtectedInternalProperty = foo.MyProtectedInternalProperty;
        var myProtectedInternalNestedInstance =
            new Foo.MyProtectedInternalNestedClass();
    }
}

大會 2

public class Baz : Foo
{
    void MyMethod1()
    {
        var myPublicProperty = MyPublicProperty;
        var myProtectedInternalProperty = MyProtectedInternalProperty;
        var thing = new MyProtectedInternalNestedClass();
    }

    void MyMethod2()
    {
        Foo foo = new Foo();
        var myPublicProperty = foo.MyPublicProperty;

        // Compile Error
        var myProtectedInternalProperty = foo.MyProtectedInternalProperty;
        // Compile Error
        var myProtectedInternalNestedInstance =
            new Foo.MyProtectedInternalNestedClass();
    }

}

public class Qux
{
    void MyMethod1()
    {
        Baz baz = new Baz();
        var myPublicProperty = baz.MyPublicProperty;

        // Compile Error
        var myProtectedInternalProperty = baz.MyProtectedInternalProperty;
        // Compile Error
        var myProtectedInternalNestedInstance =
            new Baz.MyProtectedInternalNestedClass();
    }

    void MyMethod2()
    {
        Foo foo = new Foo();
        var myPublicProperty = foo.MyPublicProperty;

        //Compile Error
        var myProtectedInternalProperty = foo.MyProtectedInternalProperty;
        // Compile Error
        var myProtectedInternalNestedInstance =
            new Foo.MyProtectedInternalNestedClass();
    }
}