属性控制类2

[AttributeUsage(AttributeTargets.Property, Inherited = false)]
    [ComVisible(true)]
    public class PropertyKeyAttribute : Attribute
    {
        public PropertyKeyAttribute(int Length)
        {
            this.Length = Length;
            this.NoneBuild = true;
        }
        public PropertyKeyAttribute()
        {
            this.NoneBuild = true;
        }

        public int Length { get; set; }
        public System.Data.SqlDbType SqlDbType { get; set; }
        public string Name { get; set; }
        public int Index { get; set; }
        public bool NoneBuild { get; set; }



        public static int GetLength<T>(string name)
        {
            PropertyKeyAttribute attr = GetPropertyKeyAttribute<T>(name);
            if (attr != null)
                return attr.Length;
            return 20;
        }
        public static System.Data.SqlDbType GetSqlDbType<T>(string name)
        {
            PropertyKeyAttribute attr = GetPropertyKeyAttribute<T>(name);
            if (attr != null)
                return attr.SqlDbType;
            return System.Data.SqlDbType.VarChar;
        }
        public static bool GetNoneBuild<T>(string name)
        {
            PropertyKeyAttribute attr = GetPropertyKeyAttribute<T>(name);
            if (attr != null)
                return attr.NoneBuild;
            return false;
        }

        public static int GetLength(object model, string name)
        {
            PropertyKeyAttribute attr = GetPropertyKeyAttribute(model, name);
            if (attr != null)
                return attr.Length;
            return 20;
        }
        public static System.Data.SqlDbType GetSqlDbType(object model, string name)
        {
            PropertyKeyAttribute attr = GetPropertyKeyAttribute(model, name);
            if (attr != null)
                return attr.SqlDbType;
            return System.Data.SqlDbType.VarChar;
        }
        public static bool GetNoneBuild(object model, string name)
        {
            PropertyKeyAttribute attr = GetPropertyKeyAttribute(model, name);
            if (attr != null)
                return attr.NoneBuild;
            return false;
        }

        #region PropertyKeyAttribute
        private static PropertyKeyAttribute GetPropertyKeyAttribute<T>(string name)
        {
            T model = (T)Activator.CreateInstance(typeof(T));
            Type type = typeof(PropertyKeyAttribute);

            PropertyInfo pi = model.GetType().GetProperty(name);
            object[] attributes = pi.GetCustomAttributes(false);
            foreach (object o in attributes)
            {
                if (o is PropertyKeyAttribute)
                {
                    //把得到的属性强制转换成PersonAttribute
                    PropertyKeyAttribute pa = (PropertyKeyAttribute)o;
                    return pa;
                }
            }
            return null;
        }
        private static PropertyKeyAttribute GetPropertyKeyAttribute(object model, string name)
        {
            try
            {
                Type type = typeof(PropertyKeyAttribute);
                PropertyInfo pi = model.GetType().GetProperty(name);
                object[] attributes = pi.GetCustomAttributes(false);
                foreach (object o in attributes)
                {
                    if (o is PropertyKeyAttribute)
                    {
                        //把得到的属性强制转换成PersonAttribute
                        PropertyKeyAttribute pa = (PropertyKeyAttribute)o;
                        return pa;
                    }
                }
            }
            catch
            {

            }
            return null;
        }
        #endregion


    }