稳扎稳打Silverlight(65) 5.0绑定之通过 ICustomTypeProvider 绑定动态生成的属性

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稳扎稳打Silverlight(65) - 5.0绑定之通过 ICustomTypeProvider 绑定动态生成的属性

作者：webabcd


介绍
Silverlight 5.0 绑定

• 绑定动态生成的属性

在线DEMO
http://www.cnblogs.com/webabcd/archive/2012/03/05/2379862.html


示例
Binding/DynamicProperty.xaml

<navigation:Page x:Class="Silverlight50.Binding.DynamicProperty" 
           xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
           xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
           xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
           xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
           mc:Ignorable="d"
           xmlns:navigation="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Navigation"
           d:DesignWidth="640" d:DesignHeight="480"
           Title="DynamicProperty Page"
                 
           xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk">
    
    <Grid x:Name="LayoutRoot">
        <sdk:DataGrid Name="dgProducts" AutoGenerateColumns="True" />
    </Grid>
</navigation:Page>

Binding/DynamicProperty.xaml.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Windows.Navigation;

namespace Silverlight50.Binding
{
    public partial class DynamicProperty : Page
    {
        public DynamicProperty()
        {
            InitializeComponent();

            this.Loaded += new RoutedEventHandler(DynamicProperty_Loaded);
        }

        void DynamicProperty_Loaded(object sender, RoutedEventArgs e)
        {
            // 动态地为 Product 类型增加属性
            Product.AddProperty("Age", typeof(int));
            Product.AddProperty("Favorite", typeof(bool));

            Product product = new Product { Name = "3DS", Category = "游戏机", Price = 1100d };

            // 为 Product 中的动态生成的属性赋值
            product.SetPropertyValue("Age", 1);
            product.SetPropertyValue("Favorite", true);

            List<Product> products = new List<Product>();
            products.Add(product);

            // 由于 Product 实现了 ICustomTypeProvider 接口，所以动态生成的属性会被绑定到 DataGrid 控件上
            dgProducts.ItemsSource = products;
        }

        // Product 实现了 ICustomTypeProvider 接口，实现此接口的话可以绑定动态生成的属性
        class Product : CustomTypeHelper<Product>
        {
            public string Name { get; set; }
            public string Category { get; set; }
            public double Price { get; set; }
        }
    }
}

Binding/CustomTypeHelper.cs

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

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

namespace Silverlight50.Binding
{
    /// <summary>
    /// 实现了 ICustomTypeProvider 和 INotifyPropertyChanged 的自定义类型的帮助类
    /// </summary>
    public class CustomTypeHelper<T> : ICustomTypeProvider, INotifyPropertyChanged
    {
        private static List<CustomPropertyInfoHelper> _customProperties = new List<CustomPropertyInfoHelper>();
        private Dictionary<string, object> _customPropertyValues;
        private CustomType _ctype;
        public event PropertyChangedEventHandler PropertyChanged;

        private void NotifyPropertyChanged(String info)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(info));
            }
        }

        public CustomTypeHelper()
        {
            _customPropertyValues = new Dictionary<string, object>();
            foreach (var property in this.GetCustomType().GetProperties())
            {
                _customPropertyValues.Add(property.Name, null);
            }
        }

        public static void AddProperty(string name)
        {
            if (!CheckIfNameExists(name))
                _customProperties.Add(new CustomPropertyInfoHelper(name, typeof(String)));
        }

        public static void AddProperty(string name, Type propertyType)
        {
            if (!CheckIfNameExists(name))
                _customProperties.Add(new CustomPropertyInfoHelper(name, propertyType));
        }

        public static void AddProperty(string name, Type propertyType, List<Attribute> attributes)
        {
            if (!CheckIfNameExists(name))
                _customProperties.Add(new CustomPropertyInfoHelper(name, propertyType, attributes));
        }

        private static bool CheckIfNameExists(string name)
        {
            if ((from p in _customProperties select p.Name).Contains(name) || (from p in typeof(T).GetProperties() select p.Name).Contains(name))
                throw new Exception("已存在同名属性：" + name);
            else return false;
        }

        public void SetPropertyValue(string propertyName, object value)
        {
            CustomPropertyInfoHelper propertyInfo = (from prop in _customProperties where prop.Name == propertyName select prop).FirstOrDefault();
            if (!_customPropertyValues.ContainsKey(propertyName))
                throw new Exception("无此属性：" + propertyName);
            if (ValidateValueType(value, propertyInfo._type))
            {
                if (_customPropertyValues[propertyName] != value)
                {
                    _customPropertyValues[propertyName] = value;
                    NotifyPropertyChanged(propertyName);
                }
            }
            else throw new Exception("值的类型错误或者对一个非空类型设置为 null");
        }

        private bool ValidateValueType(object value, Type type)
        {
            if (value == null)
                // 引用类型可以被标记为 null
                if (!type.IsValueType)
                    return true;
                else
                    return (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(Nullable<>));
            else
                return type.IsAssignableFrom(value.GetType());
        }

        public object GetPropertyValue(string propertyName)
        {
            if (_customPropertyValues.ContainsKey(propertyName))
                return _customPropertyValues[propertyName];
            else
                throw new Exception("无此属性：" + propertyName);
        }

        public PropertyInfo[] GetProperties()
        {
            return this.GetCustomType().GetProperties();
        }

        public Type GetCustomType()
        {
            if (_ctype == null)
            {
                _ctype = new CustomType(typeof(T));
            }
            return _ctype;
        }

        /// <summary>
        /// 继承抽象类 Type，以实现自定义的 Type
        /// </summary>
        private class CustomType : Type
        {
            Type _baseType;
            public CustomType(Type delegatingType)
            {
                _baseType = delegatingType;
            }
            public override Assembly Assembly
            {
                get { return _baseType.Assembly; }
            }

            public override string AssemblyQualifiedName
            {
                get { return _baseType.AssemblyQualifiedName; }
            }

            public override Type BaseType
            {
                get { return _baseType.BaseType; }
            }

            public override string FullName
            {
                get { return _baseType.FullName; }
            }

            public override Guid GUID
            {
                get { return _baseType.GUID; }
            }

            protected override TypeAttributes GetAttributeFlagsImpl()
            {
                throw new NotImplementedException();
            }

            protected override ConstructorInfo GetConstructorImpl(BindingFlags bindingAttr, Binder binder, CallingConventions callConvention, Type[] types, ParameterModifier[] modifiers)
            {

                throw new NotImplementedException();
            }

            public override ConstructorInfo[] GetConstructors(BindingFlags bindingAttr)
            {
                return _baseType.GetConstructors(bindingAttr);
            }

            public override Type GetElementType()
            {
                return _baseType.GetElementType();
            }

            public override EventInfo GetEvent(string name, BindingFlags bindingAttr)
            {
                return _baseType.GetEvent(name, bindingAttr);
            }

            public override EventInfo[] GetEvents(BindingFlags bindingAttr)
            {
                return _baseType.GetEvents(bindingAttr);
            }

            public override FieldInfo GetField(string name, BindingFlags bindingAttr)
            {
                return _baseType.GetField(name, bindingAttr);
            }

            public override FieldInfo[] GetFields(BindingFlags bindingAttr)
            {
                return _baseType.GetFields(bindingAttr);
            }

            public override Type GetInterface(string name, bool ignoreCase)
            {
                return _baseType.GetInterface(name, ignoreCase);
            }

            public override Type[] GetInterfaces()
            {
                return _baseType.GetInterfaces();
            }

            public override MemberInfo[] GetMembers(BindingFlags bindingAttr)
            {
                return _baseType.GetMembers(bindingAttr);
            }

            protected override MethodInfo GetMethodImpl(string name, BindingFlags bindingAttr, Binder binder, CallingConventions callConvention, Type[] types, ParameterModifier[] modifiers)
            {
                throw new NotImplementedException();
            }

            public override MethodInfo[] GetMethods(BindingFlags bindingAttr)
            {
                return _baseType.GetMethods(bindingAttr);
            }

            public override Type GetNestedType(string name, BindingFlags bindingAttr)
            {
                return _baseType.GetNestedType(name, bindingAttr);
            }

            public override Type[] GetNestedTypes(BindingFlags bindingAttr)
            {
                return _baseType.GetNestedTypes(bindingAttr);
            }

            public override PropertyInfo[] GetProperties(BindingFlags bindingAttr)
            {
                PropertyInfo[] clrProperties = _baseType.GetProperties(bindingAttr);
                if (clrProperties != null)
                {
                    return clrProperties.Concat(_customProperties).ToArray();
                }
                else
                    return _customProperties.ToArray();
            }

            protected override PropertyInfo GetPropertyImpl(string name, BindingFlags bindingAttr, Binder binder, Type returnType, Type[] types, ParameterModifier[] modifiers)
            {
                PropertyInfo propertyInfo = (from prop in GetProperties(bindingAttr) where prop.Name == name select prop).FirstOrDefault();
                if (propertyInfo == null)
                {
                    // 如果没有对应的clr属性则返回自定义属性
                    propertyInfo = (from prop in _customProperties where prop.Name == name select prop).FirstOrDefault();
                }
                return propertyInfo;
            }

            protected override bool HasElementTypeImpl()
            {
                throw new NotImplementedException();
            }

            public override object InvokeMember(string name, BindingFlags invokeAttr, Binder binder, object target, object[] args, ParameterModifier[] modifiers, System.Globalization.CultureInfo culture, string[] namedParameters)
            {
                return _baseType.InvokeMember(name, invokeAttr, binder, target, args, modifiers, culture, namedParameters);
            }

            protected override bool IsArrayImpl()
            {
                throw new NotImplementedException();
            }

            protected override bool IsByRefImpl()
            {
                throw new NotImplementedException();
            }

            protected override bool IsCOMObjectImpl()
            {
                throw new NotImplementedException();
            }

            protected override bool IsPointerImpl()
            {
                throw new NotImplementedException();
            }

            protected override bool IsPrimitiveImpl()
            {
                return _baseType.IsPrimitive;
            }

            public override Module Module
            {
                get { return _baseType.Module; }
            }

            public override string Namespace
            {
                get { return _baseType.Namespace; }
            }

            public override Type UnderlyingSystemType
            {
                get { return _baseType.UnderlyingSystemType; }
            }

            public override object[] GetCustomAttributes(Type attributeType, bool inherit)
            {
                return _baseType.GetCustomAttributes(attributeType, inherit);
            }

            public override object[] GetCustomAttributes(bool inherit)
            {
                return _baseType.GetCustomAttributes(inherit);
            }

            public override bool IsDefined(Type attributeType, bool inherit)
            {
                return _baseType.IsDefined(attributeType, inherit);
            }

            public override string Name
            {
                get { return _baseType.Name; }
            }
        }

        /// <summary>
        /// 继承抽象类 PropertyInfo，以实现自定仪的 PropertyInfo
        /// </summary>
        private class CustomPropertyInfoHelper : PropertyInfo
        {
            public string _name;
            public Type _type;
            public List<Attribute> _attributes = new List<Attribute>();


            public CustomPropertyInfoHelper(string name, Type type)
            {
                _name = name;
                _type = type;
            }

            public CustomPropertyInfoHelper(string name, Type type, List<Attribute> attributes)
            {
                _name = name;
                _type = type;
                _attributes = attributes;
            }

            public override PropertyAttributes Attributes
            {
                get { throw new NotImplementedException(); }
            }

            public override bool CanRead
            {
                get { return true; }
            }

            public override bool CanWrite
            {
                get { return true; }
            }

            public override MethodInfo[] GetAccessors(bool nonPublic)
            {
                throw new NotImplementedException();
            }

            public override MethodInfo GetGetMethod(bool nonPublic)
            {
                throw new NotImplementedException();
            }

            public override ParameterInfo[] GetIndexParameters()
            {
                throw new NotImplementedException();
            }

            public override MethodInfo GetSetMethod(bool nonPublic)
            {
                throw new NotImplementedException();
            }

            public override object GetValue(object obj, BindingFlags invokeAttr, Binder binder, object[] index, System.Globalization.CultureInfo culture)
            {

                return obj.GetType().GetMethod("GetPropertyValue").Invoke(obj, new[] { _name });
            }

            public override Type PropertyType
            {
                get { return _type; }
            }

            public override void SetValue(object obj, object value, BindingFlags invokeAttr, Binder binder, object[] index, System.Globalization.CultureInfo culture)
            {
                obj.GetType().GetMethod("SetPropertyValue").Invoke(obj, new[] { _name, value });
            }

            public override Type DeclaringType
            {
                get { throw new NotImplementedException(); }
            }

            public override object[] GetCustomAttributes(Type attributeType, bool inherit)
            {
                var attrs = from a in _attributes where a.GetType() == attributeType select a;
                return attrs.ToArray();
            }

            public override object[] GetCustomAttributes(bool inherit)
            {
                return _attributes.ToArray();
            }

            public override bool IsDefined(Type attributeType, bool inherit)
            {
                throw new NotImplementedException();
            }

            public override string Name
            {
                get { return _name; }
            }

            public override Type ReflectedType
            {
                get { throw new NotImplementedException(); }
            }

            internal List<Attribute> CustomAttributesInternal
            {
                get { return _attributes; }
            }
        }
    }
}

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