C#实现非枚举类型的在属性控件中可下拉选择（一）

1.效果图 

 2.对象类

    public class People
    {
        [Category("自定义")]
        [TypeConverter(typeof(OptionValuesTypeConvertor))]
        [OptionCollection(1, 54, 6)]
        public decimal ID { get; set; } = 1;

        [Category("自定义")]
        public string Name { get; set; }

        [Category("自定义")]
        [DisplayName("AA")]
        public short? Age { get; set; }

        [Category("自定义")]
        public string Location { get; set; }

        [Category("自定义")]
        [TypeConverter(typeof(OptionValuesTypeConvertor))]
        [OptionCollection("A", 54, null)]
        public string Desc { get; set; } = "A";


    }

3. 特性和类型转换器

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Reflection;

namespace AttributeTest
{
    public class OptionCollectionAttribute : Attribute
    {
        /// <summary>
        /// 构造器
        /// </summary>
        public OptionCollectionAttribute(params object[] objArr)
        {
            if (objArr != null)
            {
                foreach (var obj in objArr)
                {
                    OptionCollection.Add(obj);
                }
            }
        }

        /// <summary>
        /// 获取可供选择的项目集合
        /// </summary>
        public List<object> OptionCollection { get; private set; } = new List<object>();
    }

    public partial class OptionValuesTypeConvertor : StringConverter
    {

        public override bool GetStandardValuesSupported(ITypeDescriptorContext context)
        {
            return true;  //是否有下拉列表
        }

        public override bool GetStandardValuesExclusive(ITypeDescriptorContext context)
        {
            return true;  //是否不允许编辑
        }

        public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context)
        {
            if (context.Instance != null)
            {
                //找到当前操作的属性
                PropertyInfo currentProperty = context.Instance.GetType().GetProperties().FirstOrDefault(info => info.Name == context.PropertyDescriptor.Name);
                if (currentProperty != null)
                {
                    //找到当前操作的属性的OptionCollectionAttribute特性，并根据该特性的值得到可选集合
                    object[] optionCollectionAttributes = currentProperty.GetCustomAttributes(typeof(OptionCollectionAttribute), false);
                    if (optionCollectionAttributes != null)
                    {
                        object myAttribute = optionCollectionAttributes.FirstOrDefault(attribute => attribute is OptionCollectionAttribute);
                        if (myAttribute != null)
                        {
                            return new StandardValuesCollection((myAttribute as OptionCollectionAttribute).OptionCollection);
                        }
                    }
                }
            }
            return base.GetStandardValues(context);
        }
    }


}