カスタムプロパティ

// リスト選択型のプロパティ
public enum enumTest{a = 10,b = 20};
[Category("Design")]
[Description("テスト")]
[DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
private enumTest et;
public enumTest TestProperty
{
set { et = value; }
get { return et; }
}

// ツリー型のプロパティ
private Size st;
[Category("Design")]
[Description("テスト2")]
[DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
public Size TestProperty2
{
set { st = value; }
get { return st; }
}