ModelItemImpl.cs source code in C# .NET

Source code for the .NET framework in C#

                        

Code:

/ 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / NetFx40 / Tools / System.Activities.Presentation / System / Activities / Presentation / Model / ModelItemImpl.cs / 1305376 / ModelItemImpl.cs

                            //------------------------------------------------------------------------------ 
// Copyright (c) Microsoft Corporation.  All rights reserved.
//-----------------------------------------------------------------------------

namespace System.Activities.Presentation.Model 
{
    using System.Collections.Generic; 
    using System.ComponentModel; 
    using System.Diagnostics;
    using System.Windows; 
    using System.Windows.Markup;
    using System.Activities.Presentation.Services;
    using System.Activities.Presentation.View;
    using System.Linq; 
    using System.Runtime;
    using System.Dynamic; 
    using System.Reflection; 

 

    // This class provides the View facing ModelItem implementation, this works with the ModelTreeManager
    // and keeps the xaml up to date by intercepting every change to the model properties.
 
    class ModelItemImpl : ModelItem, IModelTreeItem, ICustomTypeDescriptor, IDynamicMetaObjectProvider
    { 
        ModelProperty contentProperty; 
        object instance;
        Type itemType; 
        Dictionary modelPropertyStore;
        ModelTreeManager modelTreeManager;
        ModelProperty nameProperty;
        List parents; 
        ModelPropertyCollectionImpl properties;
        List sources; 
        List subTreeNodesThatNeedBackLinkPatching; 
        DependencyObject view;
 

        public ModelItemImpl(ModelTreeManager modelTreeManager, Type itemType, object instance, ModelItem parent)
        {
            this.itemType = itemType; 
            this.instance = instance;
            this.modelTreeManager = modelTreeManager; 
            this.parents = new List(1); 
            this.sources = new List(1);
            if (parent != null) 
            {
                this.parents.Add(parent);
            }
            this.modelPropertyStore = new Dictionary(); 
            this.subTreeNodesThatNeedBackLinkPatching = new List();
        } 
 

 
        public override event PropertyChangedEventHandler PropertyChanged;

        public override global::System.ComponentModel.AttributeCollection Attributes
        { 
            get
            { 
                return TypeDescriptor.GetAttributes(itemType); 
            }
        } 

        public override ModelProperty Content
        {
            get 
            {
 
                if (this.contentProperty == null) 
                {
                    Fx.Assert(this.instance != null, "instance should not be null"); 

                    ContentPropertyAttribute contentAttribute = TypeDescriptor.GetAttributes(this.instance)[typeof(ContentPropertyAttribute)] as ContentPropertyAttribute;
                    if (contentAttribute != null && !String.IsNullOrEmpty(contentAttribute.Name))
                    { 
                        this.contentProperty = this.Properties.Find(contentAttribute.Name);
                    } 
                } 
                return contentProperty;
            } 
        }

        public override Type ItemType
        { 
            get
            { 
                return this.itemType; 
            }
        } 

        public ModelItem ModelItem
        {
            get 
            {
                return this; 
            } 
        }
 
        public override string Name
        {
            get
            { 
                string name = null;
                if ((this.NameProperty != null) && (this.NameProperty.Value != null)) 
                { 
                    name = (string)this.NameProperty.Value.GetCurrentValue();
                } 
                return name;
            }
            set
            { 
                if (this.NameProperty != null)
                { 
                    this.NameProperty.SetValue(value); 
                }
            } 
        }

        public override ModelItem Parent
        { 
            get
            { 
                return (this.Parents.Count() > 0) ? this.Parents.First() : null; 
            }
 
        }

        public override ModelPropertyCollection Properties
        { 
            get
            { 
                if (this.properties == null) 
                {
                    properties = new ModelPropertyCollectionImpl(this); 
                }
                return properties;
            }
        } 

        public override ModelItem Root 
        { 
            get
            { 
                return this.modelTreeManager.Root;
            }
        }
 

        // This holds a reference to the modelproperty that is currently holding this ModelItem. 
        public override ModelProperty Source 
        {
            get 
            {
                return (this.sources.Count > 0) ? this.sources.First() : null;
            }
        } 

        public override DependencyObject View 
        { 
            get
            { 
                return this.view;
            }
        }
 
        public override IEnumerable Parents
        { 
            get 
            {
                return this.parents.Concat( 
                    from source in this.sources
                    select source.Parent);
            }
        } 

        public override IEnumerable Sources 
        { 
            get
            { 
                return this.sources;
            }
        }
 

        protected ModelProperty NameProperty 
        { 
            get
            { 
                if (this.nameProperty == null)
                {
                    Fx.Assert(this.instance != null, "instance should not be null");
 
                    RuntimeNamePropertyAttribute runtimeNamePropertyAttribute = TypeDescriptor.GetAttributes(this.instance)[typeof(RuntimeNamePropertyAttribute)] as RuntimeNamePropertyAttribute;
                    if (runtimeNamePropertyAttribute != null && !String.IsNullOrEmpty(runtimeNamePropertyAttribute.Name)) 
                    { 
                        this.nameProperty = this.Properties.Find(runtimeNamePropertyAttribute.Name);
                    } 
                }
                return nameProperty;
            }
        } 

 
        Dictionary IModelTreeItem.ModelPropertyStore 
        {
            get 
            {
                return modelPropertyStore;
            }
        } 

        ModelTreeManager IModelTreeItem.ModelTreeManager 
        { 
            get
            { 
                return modelTreeManager;
            }
        }
 
        void IModelTreeItem.SetCurrentView(DependencyObject view)
        { 
            this.view = view; 
        }
 
        public override ModelEditingScope BeginEdit(string description)
        {
            return this.modelTreeManager.CreateEditingScope(description);
        } 

        public override ModelEditingScope BeginEdit() 
        { 
            return this.BeginEdit(null);
        } 

        public override object GetCurrentValue()
        {
            return this.instance; 
        }
 
        void IModelTreeItem.OnPropertyChanged(string propertyName) 
        {
            this.OnPropertyChanged(propertyName); 
        }


        void IModelTreeItem.SetParent(ModelItem dataModelItem) 
        {
            if (dataModelItem != null && !this.parents.Contains(dataModelItem)) 
            { 
                this.parents.Add(dataModelItem);
            } 
        }

        void IModelTreeItem.SetSource(ModelProperty property)
        { 
            if (!this.sources.Contains(property))
            { 
                // also check if the same parent.property is in the list as a different instance of oldModelProperty 
                ModelProperty foundProperty = this.sources.Find((modelProperty) => modelProperty.Name.Equals(property.Name) && property.Parent == modelProperty.Parent);
                if (foundProperty == null) 
                {
                    this.sources.Add(property);
                }
            } 
        }
 
        IList IModelTreeItem.SubNodesThatNeedBackLinkUpdate 
        {
            get 
            {
                return this.subTreeNodesThatNeedBackLinkPatching;
            }
        } 

        #region ICustomTypeDescriptor Members 
 
        AttributeCollection ICustomTypeDescriptor.GetAttributes()
        { 
            return this.Attributes;
        }

        string ICustomTypeDescriptor.GetClassName() 
        {
            return TypeDescriptor.GetClassName(this); 
        } 

        string ICustomTypeDescriptor.GetComponentName() 
        {
            return TypeDescriptor.GetComponentName(this);
        }
 
        TypeConverter ICustomTypeDescriptor.GetConverter()
        { 
            return ModelUtilities.GetConverter(this); 
        }
 
        EventDescriptor ICustomTypeDescriptor.GetDefaultEvent()
        {
            // we dont support events;
            return null; 
        }
 
        PropertyDescriptor ICustomTypeDescriptor.GetDefaultProperty() 
        {
            return ModelUtilities.GetDefaultProperty(this); 
        }

        object ICustomTypeDescriptor.GetEditor(Type editorBaseType)
        { 
            // we dont support editors
            return null; 
        } 

        EventDescriptorCollection ICustomTypeDescriptor.GetEvents(Attribute[] attributes) 
        {
            // we dont support events;
            return null;
        } 

        EventDescriptorCollection ICustomTypeDescriptor.GetEvents() 
        { 
            // we dont support events;
            return null; 
        }

        PropertyDescriptorCollection ICustomTypeDescriptor.GetProperties(Attribute[] attributes)
        { 
            return ModelUtilities.WrapProperties(this);
        } 
 
        PropertyDescriptorCollection ICustomTypeDescriptor.GetProperties()
        { 
            // get model properties
            List properties = new List();

 
            foreach (PropertyDescriptor modelPropertyDescriptor in ModelUtilities.WrapProperties(this))
            { 
                properties.Add(modelPropertyDescriptor); 
            }
 
            // try to see if there are pseudo builtin properties for this type.
            AttachedPropertiesService AttachedPropertiesService = this.modelTreeManager.Context.Services.GetService();
            if (AttachedPropertiesService != null)
            { 
                var nonBrowsableAttachedProperties = from attachedProperty in AttachedPropertiesService.GetAttachedProperties(this.itemType)
                                                     where !attachedProperty.IsBrowsable 
                                                     select attachedProperty; 

                foreach (AttachedProperty AttachedProperty in nonBrowsableAttachedProperties) 
                {
                    properties.Add(new AttachedPropertyDescriptor(AttachedProperty, this));
                }
            } 
            return new PropertyDescriptorCollection(properties.ToArray(), true);
        } 
 
        object ICustomTypeDescriptor.GetPropertyOwner(PropertyDescriptor pd)
        { 
            return this;
        }

        #endregion 

 
        void IModelTreeItem.RemoveParent(ModelItem oldParent) 
        {
            if (this.parents.Contains(oldParent)) 
            {
                this.parents.Remove(oldParent);
            }
        } 

        void IModelTreeItem.RemoveSource(ModelProperty oldModelProperty) 
        { 
            if (this.sources.Contains(oldModelProperty))
            { 
                this.sources.Remove(oldModelProperty);
            }
            else
            { 
                // also check if the same parent.property is in the list as a different instance of oldModelProperty
                ModelProperty foundProperty = this.sources.Find((modelProperty) => modelProperty.Name.Equals(oldModelProperty.Name) && modelProperty.Parent == oldModelProperty.Parent); 
                if (foundProperty != null) 
                {
                    this.sources.Remove(foundProperty); 
                }
            }
        }
 
        protected virtual void OnPropertyChanged(string propertyName)
        { 
            if (PropertyChanged != null) 
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); 
            }
        }

        DynamicMetaObject IDynamicMetaObjectProvider.GetMetaObject(System.Linq.Expressions.Expression parameter) 
        {
            return new ModelItemMetaObject(parameter,this); 
        } 

 


        public  object SetPropertyValue(string propertyName, object val)
        { 
            ModelProperty modelProperty = this.Properties.Find(propertyName);
            if (modelProperty != null) 
            { 
                 modelProperty.SetValue(val);
            } 
            else
            {
                 PropertyDescriptor descriptor = TypeDescriptor.GetProperties(this)[propertyName];
                 if (descriptor != null) 
                 {
                     descriptor.SetValue(this, val); 
                 } 
            }
            return GetPropertyValue(propertyName); 
        }

        public object GetPropertyValue(string propertyName)
        { 
            ModelProperty modelProperty = this.Properties.Find(propertyName);
            object value = null; 
            if (modelProperty != null) 
            {
                ModelItem valueModelitem = modelProperty.Value; 
                if (valueModelitem == null)
                {
                    value = null;
                } 
                else
                { 
                    Type itemType = valueModelitem.ItemType; 
                    if (itemType.IsPrimitive || itemType.IsEnum || itemType.Equals(typeof(String)))
                    { 
                        value = valueModelitem.GetCurrentValue();
                    }
                    else
                    { 
                        value = valueModelitem;
                    } 
                } 

            } 
            else
            {
                PropertyDescriptor descriptor  = TypeDescriptor.GetProperties(this)[propertyName];
                if (descriptor != null) 
                {
                    value = descriptor.GetValue(this); 
                } 
            }
            return value; 
        }

        class ModelItemMetaObject : System.Dynamic.DynamicMetaObject
        { 
            MethodInfo getPropertyValueMethodInfo = typeof(ModelItemImpl).GetMethod("GetPropertyValue");
            MethodInfo setPropertyValueMethodInfo = typeof(ModelItemImpl).GetMethod("SetPropertyValue"); 
 
            public ModelItemMetaObject(System.Linq.Expressions.Expression parameter, ModelItemImpl target)
                : base(parameter, BindingRestrictions.Empty,target) 
            {
            }

            public override DynamicMetaObject BindGetMember(GetMemberBinder binder) 
            {
                System.Linq.Expressions.Expression s = System.Linq.Expressions.Expression.Convert(this.Expression, typeof(ModelItemImpl)); 
                System.Linq.Expressions.Expression value = System.Linq.Expressions.Expression.Call(s, getPropertyValueMethodInfo, System.Linq.Expressions.Expression.Constant(binder.Name)); 
                return new DynamicMetaObject(value, BindingRestrictions.GetTypeRestriction(this.Expression, this.LimitType));
            } 

            public override DynamicMetaObject BindSetMember(SetMemberBinder binder, DynamicMetaObject value)
            {
                System.Linq.Expressions.Expression s = System.Linq.Expressions.Expression.Convert(this.Expression, typeof(ModelItemImpl)); 
                System.Linq.Expressions.Expression objectValue = System.Linq.Expressions.Expression.Convert(value.Expression, typeof(object));
                System.Linq.Expressions.Expression valueExp = System.Linq.Expressions.Expression.Call(s, setPropertyValueMethodInfo, System.Linq.Expressions.Expression.Constant(binder.Name), objectValue); 
                return new DynamicMetaObject(valueExp, BindingRestrictions.GetTypeRestriction(this.Expression, this.LimitType)); 
            }
        } 



    } 

 
 

 


}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
//------------------------------------------------------------------------------ 
// Copyright (c) Microsoft Corporation.  All rights reserved.
//-----------------------------------------------------------------------------

namespace System.Activities.Presentation.Model 
{
    using System.Collections.Generic; 
    using System.ComponentModel; 
    using System.Diagnostics;
    using System.Windows; 
    using System.Windows.Markup;
    using System.Activities.Presentation.Services;
    using System.Activities.Presentation.View;
    using System.Linq; 
    using System.Runtime;
    using System.Dynamic; 
    using System.Reflection; 

 

    // This class provides the View facing ModelItem implementation, this works with the ModelTreeManager
    // and keeps the xaml up to date by intercepting every change to the model properties.
 
    class ModelItemImpl : ModelItem, IModelTreeItem, ICustomTypeDescriptor, IDynamicMetaObjectProvider
    { 
        ModelProperty contentProperty; 
        object instance;
        Type itemType; 
        Dictionary modelPropertyStore;
        ModelTreeManager modelTreeManager;
        ModelProperty nameProperty;
        List parents; 
        ModelPropertyCollectionImpl properties;
        List sources; 
        List subTreeNodesThatNeedBackLinkPatching; 
        DependencyObject view;
 

        public ModelItemImpl(ModelTreeManager modelTreeManager, Type itemType, object instance, ModelItem parent)
        {
            this.itemType = itemType; 
            this.instance = instance;
            this.modelTreeManager = modelTreeManager; 
            this.parents = new List(1); 
            this.sources = new List(1);
            if (parent != null) 
            {
                this.parents.Add(parent);
            }
            this.modelPropertyStore = new Dictionary(); 
            this.subTreeNodesThatNeedBackLinkPatching = new List();
        } 
 

 
        public override event PropertyChangedEventHandler PropertyChanged;

        public override global::System.ComponentModel.AttributeCollection Attributes
        { 
            get
            { 
                return TypeDescriptor.GetAttributes(itemType); 
            }
        } 

        public override ModelProperty Content
        {
            get 
            {
 
                if (this.contentProperty == null) 
                {
                    Fx.Assert(this.instance != null, "instance should not be null"); 

                    ContentPropertyAttribute contentAttribute = TypeDescriptor.GetAttributes(this.instance)[typeof(ContentPropertyAttribute)] as ContentPropertyAttribute;
                    if (contentAttribute != null && !String.IsNullOrEmpty(contentAttribute.Name))
                    { 
                        this.contentProperty = this.Properties.Find(contentAttribute.Name);
                    } 
                } 
                return contentProperty;
            } 
        }

        public override Type ItemType
        { 
            get
            { 
                return this.itemType; 
            }
        } 

        public ModelItem ModelItem
        {
            get 
            {
                return this; 
            } 
        }
 
        public override string Name
        {
            get
            { 
                string name = null;
                if ((this.NameProperty != null) && (this.NameProperty.Value != null)) 
                { 
                    name = (string)this.NameProperty.Value.GetCurrentValue();
                } 
                return name;
            }
            set
            { 
                if (this.NameProperty != null)
                { 
                    this.NameProperty.SetValue(value); 
                }
            } 
        }

        public override ModelItem Parent
        { 
            get
            { 
                return (this.Parents.Count() > 0) ? this.Parents.First() : null; 
            }
 
        }

        public override ModelPropertyCollection Properties
        { 
            get
            { 
                if (this.properties == null) 
                {
                    properties = new ModelPropertyCollectionImpl(this); 
                }
                return properties;
            }
        } 

        public override ModelItem Root 
        { 
            get
            { 
                return this.modelTreeManager.Root;
            }
        }
 

        // This holds a reference to the modelproperty that is currently holding this ModelItem. 
        public override ModelProperty Source 
        {
            get 
            {
                return (this.sources.Count > 0) ? this.sources.First() : null;
            }
        } 

        public override DependencyObject View 
        { 
            get
            { 
                return this.view;
            }
        }
 
        public override IEnumerable Parents
        { 
            get 
            {
                return this.parents.Concat( 
                    from source in this.sources
                    select source.Parent);
            }
        } 

        public override IEnumerable Sources 
        { 
            get
            { 
                return this.sources;
            }
        }
 

        protected ModelProperty NameProperty 
        { 
            get
            { 
                if (this.nameProperty == null)
                {
                    Fx.Assert(this.instance != null, "instance should not be null");
 
                    RuntimeNamePropertyAttribute runtimeNamePropertyAttribute = TypeDescriptor.GetAttributes(this.instance)[typeof(RuntimeNamePropertyAttribute)] as RuntimeNamePropertyAttribute;
                    if (runtimeNamePropertyAttribute != null && !String.IsNullOrEmpty(runtimeNamePropertyAttribute.Name)) 
                    { 
                        this.nameProperty = this.Properties.Find(runtimeNamePropertyAttribute.Name);
                    } 
                }
                return nameProperty;
            }
        } 

 
        Dictionary IModelTreeItem.ModelPropertyStore 
        {
            get 
            {
                return modelPropertyStore;
            }
        } 

        ModelTreeManager IModelTreeItem.ModelTreeManager 
        { 
            get
            { 
                return modelTreeManager;
            }
        }
 
        void IModelTreeItem.SetCurrentView(DependencyObject view)
        { 
            this.view = view; 
        }
 
        public override ModelEditingScope BeginEdit(string description)
        {
            return this.modelTreeManager.CreateEditingScope(description);
        } 

        public override ModelEditingScope BeginEdit() 
        { 
            return this.BeginEdit(null);
        } 

        public override object GetCurrentValue()
        {
            return this.instance; 
        }
 
        void IModelTreeItem.OnPropertyChanged(string propertyName) 
        {
            this.OnPropertyChanged(propertyName); 
        }


        void IModelTreeItem.SetParent(ModelItem dataModelItem) 
        {
            if (dataModelItem != null && !this.parents.Contains(dataModelItem)) 
            { 
                this.parents.Add(dataModelItem);
            } 
        }

        void IModelTreeItem.SetSource(ModelProperty property)
        { 
            if (!this.sources.Contains(property))
            { 
                // also check if the same parent.property is in the list as a different instance of oldModelProperty 
                ModelProperty foundProperty = this.sources.Find((modelProperty) => modelProperty.Name.Equals(property.Name) && property.Parent == modelProperty.Parent);
                if (foundProperty == null) 
                {
                    this.sources.Add(property);
                }
            } 
        }
 
        IList IModelTreeItem.SubNodesThatNeedBackLinkUpdate 
        {
            get 
            {
                return this.subTreeNodesThatNeedBackLinkPatching;
            }
        } 

        #region ICustomTypeDescriptor Members 
 
        AttributeCollection ICustomTypeDescriptor.GetAttributes()
        { 
            return this.Attributes;
        }

        string ICustomTypeDescriptor.GetClassName() 
        {
            return TypeDescriptor.GetClassName(this); 
        } 

        string ICustomTypeDescriptor.GetComponentName() 
        {
            return TypeDescriptor.GetComponentName(this);
        }
 
        TypeConverter ICustomTypeDescriptor.GetConverter()
        { 
            return ModelUtilities.GetConverter(this); 
        }
 
        EventDescriptor ICustomTypeDescriptor.GetDefaultEvent()
        {
            // we dont support events;
            return null; 
        }
 
        PropertyDescriptor ICustomTypeDescriptor.GetDefaultProperty() 
        {
            return ModelUtilities.GetDefaultProperty(this); 
        }

        object ICustomTypeDescriptor.GetEditor(Type editorBaseType)
        { 
            // we dont support editors
            return null; 
        } 

        EventDescriptorCollection ICustomTypeDescriptor.GetEvents(Attribute[] attributes) 
        {
            // we dont support events;
            return null;
        } 

        EventDescriptorCollection ICustomTypeDescriptor.GetEvents() 
        { 
            // we dont support events;
            return null; 
        }

        PropertyDescriptorCollection ICustomTypeDescriptor.GetProperties(Attribute[] attributes)
        { 
            return ModelUtilities.WrapProperties(this);
        } 
 
        PropertyDescriptorCollection ICustomTypeDescriptor.GetProperties()
        { 
            // get model properties
            List properties = new List();

 
            foreach (PropertyDescriptor modelPropertyDescriptor in ModelUtilities.WrapProperties(this))
            { 
                properties.Add(modelPropertyDescriptor); 
            }
 
            // try to see if there are pseudo builtin properties for this type.
            AttachedPropertiesService AttachedPropertiesService = this.modelTreeManager.Context.Services.GetService();
            if (AttachedPropertiesService != null)
            { 
                var nonBrowsableAttachedProperties = from attachedProperty in AttachedPropertiesService.GetAttachedProperties(this.itemType)
                                                     where !attachedProperty.IsBrowsable 
                                                     select attachedProperty; 

                foreach (AttachedProperty AttachedProperty in nonBrowsableAttachedProperties) 
                {
                    properties.Add(new AttachedPropertyDescriptor(AttachedProperty, this));
                }
            } 
            return new PropertyDescriptorCollection(properties.ToArray(), true);
        } 
 
        object ICustomTypeDescriptor.GetPropertyOwner(PropertyDescriptor pd)
        { 
            return this;
        }

        #endregion 

 
        void IModelTreeItem.RemoveParent(ModelItem oldParent) 
        {
            if (this.parents.Contains(oldParent)) 
            {
                this.parents.Remove(oldParent);
            }
        } 

        void IModelTreeItem.RemoveSource(ModelProperty oldModelProperty) 
        { 
            if (this.sources.Contains(oldModelProperty))
            { 
                this.sources.Remove(oldModelProperty);
            }
            else
            { 
                // also check if the same parent.property is in the list as a different instance of oldModelProperty
                ModelProperty foundProperty = this.sources.Find((modelProperty) => modelProperty.Name.Equals(oldModelProperty.Name) && modelProperty.Parent == oldModelProperty.Parent); 
                if (foundProperty != null) 
                {
                    this.sources.Remove(foundProperty); 
                }
            }
        }
 
        protected virtual void OnPropertyChanged(string propertyName)
        { 
            if (PropertyChanged != null) 
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); 
            }
        }

        DynamicMetaObject IDynamicMetaObjectProvider.GetMetaObject(System.Linq.Expressions.Expression parameter) 
        {
            return new ModelItemMetaObject(parameter,this); 
        } 

 


        public  object SetPropertyValue(string propertyName, object val)
        { 
            ModelProperty modelProperty = this.Properties.Find(propertyName);
            if (modelProperty != null) 
            { 
                 modelProperty.SetValue(val);
            } 
            else
            {
                 PropertyDescriptor descriptor = TypeDescriptor.GetProperties(this)[propertyName];
                 if (descriptor != null) 
                 {
                     descriptor.SetValue(this, val); 
                 } 
            }
            return GetPropertyValue(propertyName); 
        }

        public object GetPropertyValue(string propertyName)
        { 
            ModelProperty modelProperty = this.Properties.Find(propertyName);
            object value = null; 
            if (modelProperty != null) 
            {
                ModelItem valueModelitem = modelProperty.Value; 
                if (valueModelitem == null)
                {
                    value = null;
                } 
                else
                { 
                    Type itemType = valueModelitem.ItemType; 
                    if (itemType.IsPrimitive || itemType.IsEnum || itemType.Equals(typeof(String)))
                    { 
                        value = valueModelitem.GetCurrentValue();
                    }
                    else
                    { 
                        value = valueModelitem;
                    } 
                } 

            } 
            else
            {
                PropertyDescriptor descriptor  = TypeDescriptor.GetProperties(this)[propertyName];
                if (descriptor != null) 
                {
                    value = descriptor.GetValue(this); 
                } 
            }
            return value; 
        }

        class ModelItemMetaObject : System.Dynamic.DynamicMetaObject
        { 
            MethodInfo getPropertyValueMethodInfo = typeof(ModelItemImpl).GetMethod("GetPropertyValue");
            MethodInfo setPropertyValueMethodInfo = typeof(ModelItemImpl).GetMethod("SetPropertyValue"); 
 
            public ModelItemMetaObject(System.Linq.Expressions.Expression parameter, ModelItemImpl target)
                : base(parameter, BindingRestrictions.Empty,target) 
            {
            }

            public override DynamicMetaObject BindGetMember(GetMemberBinder binder) 
            {
                System.Linq.Expressions.Expression s = System.Linq.Expressions.Expression.Convert(this.Expression, typeof(ModelItemImpl)); 
                System.Linq.Expressions.Expression value = System.Linq.Expressions.Expression.Call(s, getPropertyValueMethodInfo, System.Linq.Expressions.Expression.Constant(binder.Name)); 
                return new DynamicMetaObject(value, BindingRestrictions.GetTypeRestriction(this.Expression, this.LimitType));
            } 

            public override DynamicMetaObject BindSetMember(SetMemberBinder binder, DynamicMetaObject value)
            {
                System.Linq.Expressions.Expression s = System.Linq.Expressions.Expression.Convert(this.Expression, typeof(ModelItemImpl)); 
                System.Linq.Expressions.Expression objectValue = System.Linq.Expressions.Expression.Convert(value.Expression, typeof(object));
                System.Linq.Expressions.Expression valueExp = System.Linq.Expressions.Expression.Call(s, setPropertyValueMethodInfo, System.Linq.Expressions.Expression.Constant(binder.Name), objectValue); 
                return new DynamicMetaObject(valueExp, BindingRestrictions.GetTypeRestriction(this.Expression, this.LimitType)); 
            }
        } 



    } 

 
 

 


}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
                        

Link Menu

Network programming in C#, Network Programming in VB.NET, Network Programming in .NET
This book is available now!
Buy at Amazon US or
Buy at Amazon UK