/// <summary>
/// Get an associate given an indexing object
/// </summary>
/// <param name='index'>
/// The object to find the associate for
/// </param>
/// <typeparam name='T2'>
/// The type of associate to find
/// </typeparam>
public T2 Get <T2>(object index) where T2 : T, new()
{
//Get the hash code of the indexing object
var hash = index.GetHashCode();
List <WeakEntry> entries;
//See if we have a reference already
if (!references.TryGetValue(hash, out entries))
{
//If not the create the reference list
references[hash] = entries = new List <WeakEntry>();
}
//See if we have an object of the correct type and that the
//reference is still alive
var item = entries.FirstOrDefault(e => e.weakReference.IsAlive && e.weakReference.Target == index && e.associate is T2);
if (item == null)
{
//If not create one
entries.Add(item = new WeakEntry {
weakReference = new WeakReference(index), associate = new T2()
});
}
//Return the associate
return((T2)item.associate);
}
public override TItem Add(TItem item, bool replaceIfExists)
{
ArgumentValidator.EnsureArgumentNotNull(item, "item");
var key = KeyExtractor(item);
ArgumentValidator.EnsureArgumentNotNull(key, "KeyExtractor.Invoke(item)");
RegisterOperation(4);
WeakEntry entry;
if (items.TryGetValue(key, out entry))
{
var pair = entry.Value;
if (!replaceIfExists)
{
if (pair.Key != null && pair.Value != null)
{
return(pair.Value);
}
}
if (pair.Key == null)
{
items.Remove(key);
entry.Dispose();
}
}
entry = new WeakEntry(key, item, trackKeyResurrection, trackItemResurrection);
items[entry] = entry;
return(item);
}
public void Test_WeakEntry_Equals()
{
var viewModel = new TestViewModel();
var viewModel2 = new TestViewModel();
var weakEntry = new WeakEntry("Text1", viewModel, "Name");
var weakEntry1 = new WeakEntry("Text1", viewModel2, "Name");
var weakEntry2 = new WeakEntry("Text2", viewModel, "Name");
var weakEntry3 = new WeakEntry("Text1", viewModel, "Age");
var weakEntry4 = new WeakEntry("Text1", viewModel, "Name");
var weakEntry5 = new WeakEntry(string.Empty, viewModel, "Name");
var weakEntry6 = new WeakEntry("Text2", viewModel, string.Empty);
Assert.IsFalse(weakEntry.Equals(weakEntry1));
Assert.IsFalse(weakEntry.Equals(weakEntry2));
Assert.IsFalse(weakEntry.Equals(weakEntry3));
Assert.IsFalse(weakEntry1.Equals(weakEntry2));
Assert.IsFalse(weakEntry1.Equals(weakEntry3));
Assert.IsFalse(weakEntry2.Equals(weakEntry5));
Assert.IsFalse(weakEntry2.Equals(weakEntry6));
Assert.IsTrue(weakEntry1 != weakEntry3);
Assert.IsTrue(weakEntry.Equals(weakEntry4));
Assert.IsTrue(weakEntry == weakEntry4);
}
/// <summary>
/// Gets an associated object give an index of another object
/// </summary>
/// <param name='index'>
/// The object to use as an index
/// </param>
public T this[object index]
{
get
{
//Get the hash code of the indexed object
var hash = index.GetHashCode();
List <WeakEntry> entries;
//Try to get a reference to it
if (!references.TryGetValue(hash, out entries))
{
//If we failed then create a new entry
references[hash] = entries = new List <WeakEntry>();
}
//Try to get an associated object of the right type for this
//indexer/make sure it is still alive
var item = entries.FirstOrDefault(e => e.weakReference.IsAlive && e.weakReference.Target == index);
//Check if we got one
if (item == null)
{
//If we didn't then create a new one
entries.Add(item = new WeakEntry {
weakReference = new WeakReference(index), associate = new T()
});
}
//Return the associated object
return((T)item.associate);
}
}
/// <summary>
/// Clears the property binding.
/// </summary>
/// <param name="source">The source.</param>
/// <param name="target">The target.</param>
/// <param name="sourceProp">The source prop.</param>
/// <param name="targetProp">The target prop.</param>
public static void ClearPropertyBinding(Object source, INotifyPropertyChanged target, string sourceProp, string targetProp)
{
WeakEntry entry = new WeakEntry(source.GetType(), target.GetType(), sourceProp, targetProp);
Delegate setAction = GetExpressionAction(entry, source, true);
WeakSource.UnRegister(source, setAction, targetProp);
}
/// <summary>
/// Indicates whether this instance and a specified object are equal.
/// </summary>
/// <param name="obj">Another object to compare to.</param>
/// <returns>
/// true if <paramref name="obj"/> and this instance are the same type and represent the same value; otherwise, false.
/// </returns>
public override bool Equals(object obj)
{
WeakEntry entry = (WeakEntry)obj;
return((this.SourceType == entry.SourceType) && (this.TargetType == entry.TargetType) &&
(this.SourceProp == entry.SourceProp) && (this.TargetProp == entry.TargetProp));
}
/// <summary>
/// Clears the property binding.
/// </summary>
/// <param name="source">The source.</param>
/// <param name="target">The target.</param>
/// <param name="sourceProp">The source prop.</param>
/// <param name="targetProp">The target prop.</param>
public static void ClearPropertyBinding(Object source, INotifyPropertyChanged target, string sourceProp, string targetProp)
{
WeakEntry entry = new WeakEntry(source.GetType(), target.GetType(), sourceProp, targetProp);
Delegate setAction = GetExpressionAction(entry, source, true);
WeakSource.UnRegister(source, setAction, targetProp);
}
/// <summary>
/// Gets the expression action.
/// </summary>
/// <param name="entry">The entry.</param>
/// <param name="source">The source.</param>
/// <param name="createNew">if set to <c>true</c> [create new].</param>
/// <param name="converter">The converter.</param>
/// <returns></returns>
private static Delegate GetExpressionAction(WeakEntry entry, object source, bool createNew, IDataConverter converter = null)
{
Delegate action = null;
if (_expressionSources.ContainsKey(entry))
{
action = _expressionSources[entry];
}
else if (createNew)
{
///// Code of the below Expression Tree ////////////////////////////////
//if (converter != null)
//{
// target.Property = converter.Convert(source.Property, parameter);
//}
//else
//{
// if (target.Property.GetType() == source.Property.GetType())
// {
// target.Property = source.Property;
// }
// else
// {
// throw new InvalidOperationException("The property type between binding source and target does not match, please use IDataConverter to do custom convert.");
// }
//}
//////////////////////////////////////////////////////////////////////////
//Set Property
var prop = entry.SourceType.GetProperty(entry.SourceProp);
var paraObj = Expression.Parameter(entry.SourceType);
//Get Property
var targetProperty = entry.TargetType.GetProperty(entry.TargetProp);
var paraTarget = Expression.Parameter(entry.TargetType);
var getter = Expression.Property(paraTarget, targetProperty);
//Combine
Expression boy;
var paraConvert = Expression.Variable(typeof(IDataConverter));
var paraParameter = Expression.Variable(typeof(object));
boy = Expression.IfThenElse(
Expression.NotEqual(paraConvert, Expression.Constant(null)),
Expression.Call(paraObj, prop.GetSetMethod(), Expression.Convert(Expression.Call(paraConvert, typeof(IDataConverter).GetMethod("Convert"),
Expression.Convert(getter, typeof(object)), Expression.Convert(paraParameter, typeof(object))), prop.PropertyType)),
Expression.IfThenElse(
Expression.Equal(Expression.Constant(prop.PropertyType, typeof(Type)), Expression.Constant(getter.Type, typeof(Type))),
Expression.Call(paraObj, prop.GetSetMethod(), Expression.Convert(Expression.Convert(getter, typeof(object)), prop.PropertyType)),
Expression.Throw(Expression.Constant(new InvalidOperationException(
"The property type between binding source and target does not match, please use IDataConverter to do custom convert.")))));
action = Expression.Lambda(boy, paraObj, paraTarget, paraConvert, paraParameter).Compile();
_expressionSources.Add(entry, action);
}
return(action);
}
/// <summary>
/// Sets the property binding.
/// </summary>
/// <param name="source">The source.</param>
/// <param name="target">The target.</param>
/// <param name="sourceProp">The source prop.</param>
/// <param name="targetProp">The target prop.</param>
/// <param name="notify">if set to <c>true</c> update immediately.</param>
/// <param name="converter">The converter.</param>
/// <param name="parameter">The converter parameter.</param>
public static void SetPropertyBinding(Object source, INotifyPropertyChanged target, string sourceProp, string targetProp, bool notify = true, IDataConverter converter = null, object parameter = null)
{
WeakEntry entry = new WeakEntry(source.GetType(), target.GetType(), sourceProp, targetProp);
Delegate setAction = GetExpressionAction(entry, source, true, converter);
WeakSource wSource = WeakSource.Register(source, target, setAction, targetProp, converter, parameter);
if (notify)
{
wSource.NotifyPropertyChanged(target, targetProp);
}
}
/// <summary>
/// Sets the property binding.
/// </summary>
/// <param name="source">The source.</param>
/// <param name="target">The target.</param>
/// <param name="sourceProp">The source prop.</param>
/// <param name="targetProp">The target prop.</param>
/// <param name="notify">if set to <c>true</c> update immediately.</param>
/// <param name="converter">The converter.</param>
/// <param name="parameter">The converter parameter.</param>
public static void SetPropertyBinding(Object source, INotifyPropertyChanged target, string sourceProp, string targetProp, bool notify = true, IDataConverter converter = null, object parameter = null)
{
WeakEntry entry = new WeakEntry(source.GetType(), target.GetType(), sourceProp, targetProp);
Delegate setAction = GetExpressionAction(entry, source, true, converter);
WeakSource wSource = WeakSource.Register(source, target, setAction, targetProp, converter, parameter);
if (notify)
{
wSource.NotifyPropertyChanged(target, targetProp);
}
}
/// <summary>
/// Gets the expression action.
/// </summary>
/// <param name="entry">The entry.</param>
/// <param name="source">The source.</param>
/// <param name="createNew">if set to <c>true</c> [create new].</param>
/// <param name="converter">The converter.</param>
/// <returns></returns>
private static Delegate GetExpressionAction(WeakEntry entry, object source, bool createNew, IDataConverter converter = null)
{
Delegate action = null;
if (_expressionSources.ContainsKey(entry))
{
action = _expressionSources[entry];
}
else if (createNew)
{
///// Code of the below Expression Tree ////////////////////////////////
//if (converter != null)
//{
// target.Property = converter.Convert(source.Property, parameter);
//}
//else
//{
// if (target.Property.GetType() == source.Property.GetType())
// {
// target.Property = source.Property;
// }
// else
// {
// throw new InvalidOperationException("The property type between binding source and target does not match, please use IDataConverter to do custom convert.");
// }
//}
//////////////////////////////////////////////////////////////////////////
//Set Property
var prop = entry.SourceType.GetProperty(entry.SourceProp);
var paraObj = Expression.Parameter(entry.SourceType);
//Get Property
var targetProperty = entry.TargetType.GetProperty(entry.TargetProp);
var paraTarget = Expression.Parameter(entry.TargetType);
var getter = Expression.Property(paraTarget, targetProperty);
//Combine
Expression boy;
var paraConvert = Expression.Variable(typeof(IDataConverter));
var paraParameter = Expression.Variable(typeof(object));
boy = Expression.IfThenElse(
Expression.NotEqual(paraConvert, Expression.Constant(null)),
Expression.Call(paraObj, prop.GetSetMethod(), Expression.Convert(Expression.Call(paraConvert, typeof(IDataConverter).GetMethod("Convert"),
Expression.Convert(getter, typeof(object)), Expression.Convert(paraParameter, typeof(object))), prop.PropertyType)),
Expression.IfThenElse(
Expression.Equal(Expression.Constant(prop.PropertyType, typeof(Type)), Expression.Constant(getter.Type, typeof(Type))),
Expression.Call(paraObj, prop.GetSetMethod(), Expression.Convert(Expression.Convert(getter, typeof(object)), prop.PropertyType)),
Expression.Throw(Expression.Constant(new InvalidOperationException(
"The property type between binding source and target does not match, please use IDataConverter to do custom convert.")))));
action = Expression.Lambda(boy, paraObj, paraTarget, paraConvert, paraParameter).Compile();
_expressionSources.Add(entry, action);
}
return action;
}
