public static void Main()
{
DetectingAttributes.Go();
MatchingAttributes.Go();
ConditionalAttributeDemo.Go();
}
/// <summary>
/// Create a new dependency property factory for a specific set of properties.
/// </summary>
/// <param name = "ownerType">The owner type of the dependency properties.</param>
/// <param name = "enforceNamingConventions">
/// Whether or not to throw exceptions when the naming conventions aren't followed.
/// See http://msdn.microsoft.com/en-us/library/bb613563.aspx.
/// </param>
/// <param name = "checkForStatic">Whether or not to check whether the factory is static.</param>
protected DependencyPropertyFactory(Type ownerType, bool enforceNamingConventions, bool checkForStatic)
: base(ownerType, true)
{
Contract.Requires(typeof(T).IsPublic || typeof(T).IsNestedPublic);
Properties = new Dictionary <T, DependencyProperty>();
_enforceWpfConvention = enforceNamingConventions;
// When coercion is used, all enum values should be independent flag values, different from 0.
if (MatchingAttributes.Any(a => a.Key.GetAttributes <CoercionHandlerAttribute>().Length > 0))
{
T none = default(T);
Type enumType = typeof(T);
bool correctImplementation =
enumType.IsFlagsEnum() &&
EnumHelper <T> .GetValues().All(v => EnumHelper <T> .GetFlaggedValues(v).Count() == 1 && !v.Equals(none));
if (!correctImplementation)
{
string message = String.Format(
"In order to use coercion, each enum value of {0} should be an individual flag value, different from 0.", enumType);
throw new InvalidImplementationException(message);
}
}
// Check whether the factory itself is defined as a static field.
// TODO: Can part of this logic be moved to ReflectionHelper?
if (checkForStatic)
{
FieldInfo[] fields = OwnerType.GetFields(
BindingFlags.FlattenHierarchy | BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
bool validFactory
= fields
.Where(field => field.FieldType == typeof(DependencyPropertyFactory <T>) && field.IsStatic)
.Any();
if (!validFactory)
{
throw new InvalidImplementationException(
"Incorrect usage of DependencyPropertyFactory in class '" + OwnerType.Name + "'. " +
"A DependencyPropertyFactory needs to be created as a static field inside it's owner class.");
}
}
// Check whether callback attributes are applied to non-static functions. They should be static!
var callbackMethods =
from method in OwnerType.GetMethods(ReflectionHelper.FlattenedClassMembers)
from attribute in method.GetAttributes <AbstractDependencyPropertyCallbackAttribute>()
select method;
if (!callbackMethods.All(m => m.IsStatic))
{
throw new InvalidImplementationException(
"Not all dependency property callback functions are defined as static in type '" + OwnerType.Name + "'.");
}
// Create dependency properties.
var properties =
from item in MatchingAttributes
where item.Key is PropertyInfo
select item;
foreach (var item in properties)
{
var attribute = (DependencyPropertyAttribute)item.Value[0];
CreateDependencyProperty(GetDependencyPropertyInfo(item.Key as PropertyInfo, attribute));
}
// Create attached properties.
var attachedProperties =
from item in MatchingAttributes
where item.Key is MethodInfo
from attribute in item.Value
group new
{
MemberInfo = item.Key,
Attribute = (DependencyPropertyAttribute)attribute
} by attribute.GetId();
foreach (var item in attachedProperties)
{
var attachedProperty = item.ToList();
bool valid = false;
if (attachedProperty.Count <= 2)
{
MethodInfo[] methods = attachedProperty.Select(p => (MethodInfo)p.MemberInfo).ToArray();
MethodInfo getter = methods.Single(m => m.Name.StartsWith(GetPrefix));
MethodInfo setter = methods.SingleOrDefault(m => m.Name.StartsWith(SetPrefix) && m.ReturnType == typeof(void));
// Verify whether getter and setter correspond.
// TODO: Do typechecking of parameters?
if (setter != null && getter.Name.Substring(GetPrefix.Length) == setter.Name.Substring(SetPrefix.Length))
{
// Extract settings.
var attributes = attachedProperty.Select(a => a.Attribute).ToArray();
var id = (T)attachedProperty.First().Attribute.GetId();
// TODO: Allow checking whether or not the default value is set or not.
var defaultValues =
attributes.Where(a => a.DefaultValue != null).Select(a => a.DefaultValue).ToArray();
var readOnlySettings =
attributes.Where(a => a.IsReadOnlySet()).Select(a => a.IsReadOnlySet() ? a.IsReadOnly() : new bool?()).ToArray();
if (!defaultValues.AllEqual() || !readOnlySettings.AllEqual())
{
throw new InvalidImplementationException(
"All set options of \"" + typeof(DependencyPropertyAttribute) +
"\" should correspond with attributes with the same ID." +
" Preferably only set options on one of the attributes.");
}
DependencyPropertyInfo info = GetAttachedDependencyPropertyInfo(
getter, setter,
id, defaultValues.FirstOrDefault(), readOnlySettings.FirstOrDefault());
// HACK: For collections, use a dependency property with non-matching name so the getter is called the first time,
// so it can be initialized and doesn't need to be initialized through XAML.
if (info.Type.ImplementsInterface(typeof(ICollection)))
{
info.Name = info.Name + "Internal";
_attachedCollectionsTypes.Add(info.Id, info.Type);
}
CreateDependencyProperty(info);
valid = true;
}
}
if (!valid)
{
throw new InvalidImplementationException(
"Invalid usage of the attribute " + typeof(DependencyPropertyAttribute) + ". " +
"To create an attached property, apply it to a correctly named get and optionally corresponding set method. ");
}
}
}