/// <summary>
/// Initializes a new instance of the <see cref="PropertyBinding"/> class.
/// </summary>
/// <param name="sourceProperty">The source property details.</param>
/// <param name="targetProperty">The target property details.</param>
/// <param name="direction">The direction of the binding.</param>
public PropertyBinding(PropertyDetails sourceProperty, PropertyDetails targetProperty, PropertyBindingDirection direction)
{
SourceProperty = sourceProperty;
TargetProperty = targetProperty;
Direction = direction;
UpdateFromDefault();
}
/// <summary>
/// Binds the value of a property of a source object to a property of a target object.
/// Whenever either property is changed, the other side of the binding is set to the same
/// value. To avoid endless loops, the PropertyChanged event must only be raised when the
/// value actually changed, not already on assignment. The target property is updated
/// immediately after setting up the binding, if <paramref name="direction"/> is not
/// OneWayToSource.
/// </summary>
/// <typeparam name="TTarget">Type that defines the target property.</typeparam>
/// <typeparam name="TSource">Type that defines the source property.</typeparam>
/// <typeparam name="TProperty">Value type of both properties.</typeparam>
/// <param name="target">Instance of the type that defines the target property. Must implement INotifyPropertyChanged.</param>
/// <param name="targetExpr">Lambda expression of the target property.</param>
/// <param name="source">Instance of the type that defines the source property. Must implement INotifyPropertyChanged.</param>
/// <param name="sourceExpr">Lambda expression of the source property.</param>
/// <param name="direction">The direction of property value updates.</param>
/// <example>
/// Bind a source property to a local property of the same type:
/// <code>
/// this.BindProperty(me => me.TargetProperty, source, src => src.SourceProperty);
/// </code>
/// </example>
public static void BindProperty <TTarget, TSource, TProperty>(
this TTarget target,
Expression <Func <TTarget, TProperty> > targetExpr,
TSource source,
Expression <Func <TSource, TProperty> > sourceExpr,
PropertyBindingDirection direction = PropertyBindingDirection.TwoWay)
where TTarget : INotifyPropertyChanged
where TSource : INotifyPropertyChanged
{
// Initialise all expression parts and reflected properties
var targetMemberExpr = targetExpr.Body as MemberExpression;
if (targetMemberExpr == null)
{
throw new ArgumentException("Unsupported target expression type.");
}
PropertyInfo targetProperty = targetMemberExpr.Member as PropertyInfo;
if (targetProperty == null)
{
throw new ArgumentException("Unsupported target expression type.");
}
var sourceMemberExpr = sourceExpr.Body as MemberExpression;
if (sourceMemberExpr == null)
{
throw new ArgumentException("Unsupported source expression type.");
}
PropertyInfo sourceProperty = sourceMemberExpr.Member as PropertyInfo;
if (sourceProperty == null)
{
throw new ArgumentException("Unsupported source expression type.");
}
if (direction != PropertyBindingDirection.OneWayToSource)
{
// When the source changes, update the target
source.PropertyChanged += (s, e) =>
{
if (e.PropertyName == sourceProperty.Name)
{
targetProperty.SetValue(
target,
sourceProperty.GetValue(source, null),
null);
}
};
}
if (direction != PropertyBindingDirection.OneWayToTarget)
{
// When the target changes, update the source
target.PropertyChanged += (s, e) =>
{
if (e.PropertyName == targetProperty.Name)
{
sourceProperty.SetValue(
source,
targetProperty.GetValue(target, null),
null);
}
};
}
if (direction != PropertyBindingDirection.OneWayToSource)
{
// Update the target immediately
targetProperty.SetValue(
target,
sourceProperty.GetValue(source, null),
null);
}
}
/// <summary> /// Creates a property binding with the given source property and target property. /// </summary> /// <param name="sourceProperty">The source property.</param> /// <param name="targetProperty">The target property.</param> /// <param name="direction">The direction of the property binding.</param> /// <returns>A generated property binding.</returns> public static PropertyBinding Create <TSource, TTarget>(PropertyDetails <TSource> sourceProperty, PropertyDetails <TTarget> targetProperty, PropertyBindingDirection direction) => new PropertyBinding <TSource, TTarget>(sourceProperty, targetProperty, direction);
/// <summary> /// Creates a property binding with the given source property and target property. /// </summary> /// <param name="sourceProperty">The source property.</param> /// <param name="targetProperty">The target property.</param> /// <param name="direction">The direction of the property binding.</param> /// <returns>A generated property binding.</returns> public static PropertyBinding Create <TSource, TTarget>(Expression <Func <TSource> > sourceProperty, Expression <Func <TTarget> > targetProperty, PropertyBindingDirection direction) => new PropertyBinding <TSource, TTarget>(sourceProperty, targetProperty, direction);
/// <summary>
/// Creates a property binding with the given source property and target property.
/// </summary>
/// <param name="sourceProperty">The source property.</param>
/// <param name="targetProperty">The target property.</param>
/// <returns>A generated property binding.</returns>
public static PropertyBinding Create(PropertyDetails sourceProperty, PropertyDetails targetProperty, PropertyBindingDirection direction)
{
var propertyBindingType = typeof(PropertyBinding <,>).MakeGenericType(sourceProperty.Type, targetProperty.Type);
return((PropertyBinding)propertyBindingType.CreateInstance(sourceProperty, targetProperty, direction));
}
