/// <summary>
/// Sets the value of a property. If the value is different the current value of the property, <see cref="PropertyChanged"/> event is raised.
/// </summary>
/// <typeparam name="T">the type of the property</typeparam>
/// <returns>True if the property value has been updated, otherwise false</returns>
protected bool SetPropertyValue <T>(Expression <Func <T> > propertyAccessor, T value)
{
bool valueChanged = false;
string propertyName = GetPropertyName(propertyAccessor);
if (PropertyValues.ContainsKey(propertyName))
{
PropertyValues.AddOrUpdate(propertyName, value, (key, previousValue) =>
{
if (typeof(T).IsValueType)
{
valueChanged = previousValue == null || !previousValue.Equals(value);
}
else
{
// ReSharper disable CompareNonConstrainedGenericWithNull
valueChanged = !previousValue?.Equals(value) ?? value != null;
// ReSharper restore CompareNonConstrainedGenericWithNull
}
return(value);
});
if (valueChanged)
{
OnPropertyChanged(propertyName);
}
}
else
{
valueChanged = true;
PropertyValues.AddOrUpdate(propertyName, value, (key, previousValue) => value);
OnPropertyChanged(propertyName);
}
return(valueChanged);
}
/// <summary>
/// Sets the value of a property. If the value is different the current value of the property,
/// <see cref="PropertyChanged" /> event is raised.
/// </summary>
/// <typeparam name="T">the type of the property</typeparam>
/// <returns>True if the property value has been updated, otherwise false</returns>
protected bool SetPropertyValue <T>(Expression <Func <T> > propertyAccessor, T value)
{
var valueChanged = false;
var propertyName = GetPropertyName(propertyAccessor);
if (PropertyValues.ContainsKey(propertyName))
{
PropertyValues.AddOrUpdate(propertyName, value, (key, previousValue) =>
{
if (typeof(T).GetTypeInfo().IsValueType)
{
valueChanged = previousValue == null || !previousValue.Equals(value);
}
else
{
valueChanged = !previousValue?.Equals(value) ?? value != null;
}
return(value);
});
if (valueChanged)
{
OnPropertyChanged(propertyName);
}
}
else
{
valueChanged = true;
PropertyValues.AddOrUpdate(propertyName, value, (key, previousValue) => value);
OnPropertyChanged(propertyName);
}
return(valueChanged);
}
