プロパティのアクセシビリティと PropertyInfo

PropertyInfo を取得する際、アクセシビリティで混乱したので調査。

プロパティ定義			GetProperties の引数 BindingFlags	PropertyInfo 情報
get アクセサ	set アクセサ	CanRead		CanWrite	GetMethod .Attributes	SetMethod .Attributes
public	public	Public			Public	Public
public	private	Public			Public	Private
private	public	Public			Private	Public
public	-	Public			Public	-
-	public	Public			-	Public
protected	protected	NonPublic			Family	Family
internal	internal	NonPublic			Assembly	Assembly
protected internal	protected internal	NonPublic			FamORAssem	FamORAssem
private	private	NonPublic			Private	Private
private	-	NonPublic			Private	-
-	private	NonPublic			-	Private

※GetMethod と SetMethod の MethodBase.Attributes は、Public／Private／Family／Assembly／FamORAssem
のみ抽出

[調査コード]

class Program
{
    static void Main(string[] args)
    {
        ShowPropInfo(new Props());
    }
    static void ShowPropInfo<T>(T source)
    {
        var t = typeof(T);
        Console.WriteLine("[Public]");
        ShowPropDetail(t.GetProperties(BindingFlags.Instance | BindingFlags.Public));

        Console.WriteLine();

        Console.WriteLine("[NonPublic]");
        ShowPropDetail(t.GetProperties(BindingFlags.Instance | BindingFlags.NonPublic));
    }
    static void ShowPropDetail(IEnumerable<PropertyInfo> props)
    {
        foreach( var prop in props ){
            Console.WriteLine("Name:{0} CanRead:{1} CanWrite:{2}",
                prop.Name, prop.CanRead, prop.CanWrite);

            if( prop.GetMethod != null ) Console.WriteLine(
                "  <Get> Name:{0} Attributes:[{1}]",
                prop.GetMethod.Name, prop.GetMethod.Attributes);

            if( prop.SetMethod != null ) Console.WriteLine(
                "  <Set> Name:{0} Attributes:[{1}]",
                prop.SetMethod.Name, prop.SetMethod.Attributes);
        }
    }
}

class Props
{
    public int plGetSet { get; set; }
    public int plGetpvSet { get; private set; }
    public int pvGetplSet { private get; set; }
    public int plGet { get { return 0; } }
    public int plSet { set { } }

    protected int ptGetSet { get; set; }
    internal int inGetSet { get; set; }
    protected internal int ptinGetSet { get; set; }

    private int pvGetSet { get; set; }
    private int pvGet { get { return 0;} }
    private int pvSet { set { } }
}

まとめ

• get アクセサ／set アクセサのいずれかが public → BindingFlags.Public の対象
• 上記以外 → BindingFlags.NonPublic の対象

• get アクセサ無し → CanRead ： False → GetMethod ： null
• set アクセサ無し → CanWrite ： False → SetMethod ： null