PropertyGrid—属性类别排序

属性默认按照字母顺序排序，有时，我们想要按自定义的顺序排序

这个工具类可以把每个属性类别里的属性排序，但是不能把属性类别排序。

为属性类添加属性：[TypeConverter(typeof(PropertySorter))]
为每个属性添加属性：[PropertyOrder(10)]

private void Form_Load(object sender, EventArgs e)
{
    propertyGrid1.SelectedObject = new Person();
}
[TypeConverter(typeof(PropertySorter))]
[DefaultProperty("Name")]
public class Person
{
    protected const string PERSONAL_CAT = "Personal Details";

    private string _name = "Bob";
    private DateTime _birthday = new DateTime(,,);

    [Category(PERSONAL_CAT), PropertyOrder()]
    public string Name
    {
        get {return _name;}
        set {_name = value;}
    }

    [Category(PERSONAL_CAT), PropertyOrder()]
    public DateTime Birthday
    {
        get {return _birthday;}
        set {_birthday = value;}
    }

    [Category(PERSONAL_CAT), PropertyOrder()]
    public int Age
    {
        get
        {
            TimeSpan age = DateTime.Now - _birthday;
            return (int)age.TotalDays / ;
        }
    }
}

工具类

//
// (C) Paul Tingey 2004
//
using System;
using System.Collections;
using System.ComponentModel;

namespace OrderedPropertyGrid
{
    public class PropertySorter : ExpandableObjectConverter
    {
        #region Methods
        public override bool GetPropertiesSupported(ITypeDescriptorContext context)
        {
            return true;
        }

        public override PropertyDescriptorCollection GetProperties(ITypeDescriptorContext context, object value, Attribute[] attributes)
        {
            //
            // This override returns a list of properties in order
            //
            PropertyDescriptorCollection pdc = TypeDescriptor.GetProperties(value, attributes);
            ArrayList orderedProperties = new ArrayList();
            foreach (PropertyDescriptor pd in pdc)
            {
                Attribute attribute = pd.Attributes[typeof(PropertyOrderAttribute)];
                if (attribute != null)
                {
                    //
                    // If the attribute is found, then create an pair object to hold it
                    //
                    PropertyOrderAttribute poa = (PropertyOrderAttribute)attribute;
                    orderedProperties.Add(new PropertyOrderPair(pd.Name,poa.Order));
                }
                else
                {
                    //
                    // If no order attribute is specifed then given it an order of 0
                    //
                    orderedProperties.Add(new PropertyOrderPair(pd.Name,));
                }
            }
            //
            // Perform the actual order using the value PropertyOrderPair classes
            // implementation of IComparable to sort
            //
            orderedProperties.Sort();
            //
            // Build a string list of the ordered names
            //
            ArrayList propertyNames = new ArrayList();
            foreach (PropertyOrderPair pop in orderedProperties)
            {
                propertyNames.Add(pop.Name);
            }
            //
            // Pass in the ordered list for the PropertyDescriptorCollection to sort by
            //
            return pdc.Sort((string[])propertyNames.ToArray(typeof(string)));
        }
        #endregion
    }

    #region Helper Class - PropertyOrderAttribute
    [AttributeUsage(AttributeTargets.Property)]
    public class PropertyOrderAttribute : Attribute
    {
        //
        // Simple attribute to allow the order of a property to be specified
        //
        private int _order;
        public PropertyOrderAttribute(int order)
        {
            _order = order;
        }

        public int Order
        {
            get
            {
                return _order;
            }
        }
    }
    #endregion

    #region Helper Class - PropertyOrderPair
    public class PropertyOrderPair : IComparable
    {
        private int _order;
        private string _name;
        public string Name
        {
            get
            {
                return _name;
            }
        }

        public PropertyOrderPair(string name, int order)
        {
            _order = order;
            _name = name;
        }

        public int CompareTo(object obj)
        {
            //
            // Sort the pair objects by ordering by order value
            // Equal values get the same rank
            //
            int otherOrder = ((PropertyOrderPair)obj)._order;
            if (otherOrder == _order)
            {
                //
                // If order not specified, sort by name
                //
                string otherName = ((PropertyOrderPair)obj)._name;
                return string.Compare(_name,otherName);
            }
            else if (otherOrder > _order)
            {
                return -;
            }
            return ;
        }
    }
    #endregion
}

　　属性排序方式

　　属性的排序是基于容器类的.sort();实现的。因为控件通过TypeConverter.GetProperties();方法获得PropertyDescriptorCollection类型的对象。并根据此对象的元素设定SelectedObject的表现方式等。故实现属性类的排序首先需要获得对象的集合，然后使其按指定方式排序。因为sort()方法接受string[]类型的参数作为排序依据，其相对于属性的排序是比对其Name属性（或DisplayName属性），而我们需要在保证本地化的前提下完成排序，所以我们要在抛开其Name属性（或者DisplayName）的前提下实现排序（理论上我们能获得属性property的name属性，即方法名，但是笔者在实践中设定字符串数组中依次填入name作为排序依据，未能成功，非本地化的情况下可以实现，现在仍未找到原因，猜测其可能会以DisplayName替代Name返回？？？）。基于以上分析与原因，我们需要给每个属性Property添加一个属性Attribute可以作为排序的依据。到此，存在一个问题。如何根据新的属性（代称为order）对Property进行排序。较为优雅的方法是实现IComparable()接口。

　　事例代码如下：（部分代码来源于网络，感谢先辈）

[AttributeUsage(AttributeTargets.Property)]
    public class PropertyOrderAttribute : Attribute//自定义Attribute类，向property提供

```````````````````````````````````````````````````//order属性
    {
        private int order;

        public PropertyOrderAttribute(int order)
        {
            this.order = order;
        }

        public int Order
        {
            get
            {
                return order;
            }
        }
    }

 class TestPropertyDescriptor : PropertyDescriptor,IComparable//继承PropertyDescriptor类并实现IComparable接口
    {
        private PropertyDescriptor basePropertyDescriptor;
        private int order;
        ...

                //构造函数

        public TestPropertyDescriptor(PropertyDescriptor basePropertyDescriptor): base(basePropertyDescriptor)
        {
            this.basePropertyDescriptor = basePropertyDescriptor;
            order = GetOrder(basePropertyDescriptor.Attributes);
        }

                //获得property的order属性

        private int GetOrder(AttributeCollection ac)
        {
            foreach (Attribute a in ac)
            {
                if (a is PropertyOrderAttribute)
                    return ((PropertyOrderAttribute)a).Order;
            }
            return ;

        }

        ...

        #region "IComparable"
        public int CompareTo(object tpd)//实现接口，使此类的对象可以依据order进行比较、排序
        {
            TestPropertyDescriptor other = (TestPropertyDescriptor)tpd;
            if (order == other.order) return string.Compare(Name, other.Name);
            else return (order > other.order) ?  : -;
        }
        #endregion
    }

class ICustomTDClass1: Class1 , ICustomTypeDescriptor//Class1为需要对其属性进行排序的自定义类。

{

...

 public PropertyDescriptorCollection GetProperties(Attribute[] attributes)
       {

            PropertyDescriptorCollection tmpPDC = TypeDescriptor.GetProperties(typeof(ICustomTDClass1), attributes);
            PropertyDescriptorCollection result = new PropertyDescriptorCollection(null);
            ArrayList orderPdList = new ArrayList();

            foreach (PropertyDescriptor pd in tmpPDC)
            {
                 TestPropertyDescriptor tpd = new TestPropertyDescriptor(pd);
                 result.Add(tpd);
                 orderPdList.Add(tpd);

            }
            orderPdList.Sort();//根据order排序
            ArrayList propertyNames = new ArrayList();
            foreach (TestPropertyDescriptor propertyAttributes in orderPdList)//获得排序后的DisplayName数组
            {
                propertyNames.Add(propertyAttributes.DisplayName);
            }

            return result.Sort((string[])propertyNames.ToArray(typeof(string)));//根据数组对结果排序，注意这里不能直接return `````````````````````````````````````````````````````````````````````````````````````````````//result.Sort(),因为在result里存着的是PropertyDescriptor类`````````````````````````````````````````````````````````````````````````````````````````````//型的对象，而不是我们定义的TestPropertyDescriptor类`````````````````````````````````````````````````````````````````````````````````````````````//型。至此，排序功能圆满完成。
        }
...

}

参考

1. PropertyGrid排序

2. PropertyGrid控件 分类（Category）及属性（Property）排序

3. Ordering Items in the Property Grid