I have created this class
public class CustomLayoutAttributes: UICollectionViewLayoutAttributes
{
public float PhotoHeight { get; set; }
public override NSObject Copy (NSZone zone)
{
CustomLayoutAttributes copy = base.Copy(zone) as CustomLayoutAttributes;
copy.PhotoHeight = PhotoHeight;
return copy;
}
public override bool IsEqual (NSObject anObject)
{
CustomLayoutAttributes attributes = anObject as CustomLayoutAttributes;
if (attributes != null) {
if (attributes.PhotoHeight == PhotoHeight) {
return base.IsEqual (anObject);
}
}
return false;
}
public CustomLayoutAttributes (IntPtr ptr) : base(ptr)
{
}
}
And in my CustomCollectionViewLayout PrepareLayout method I try to create an instance but always get null.
[Register("CustomCollectionViewLayout")]
public class CustomCollectionViewLayout : UICollectionViewLayout
{
public override void PrepareLayout ()
{
// stuff...
CustomLayoutAttributes attributes = CustomLayoutAttributes.CreateForCell(indexPath) as CustomLayoutAttributes;
if (attributes != null) {
// Never gets in here, always null
}
// stuff...
}
}
I have applied the same login in Swift iOS and it works perfect.
Need to use the generic version of CreateForCell:
UICollectionViewLayout.CreateForCell<CustomLayoutAttributes>(indexPath);
This is because C# doesn't have virtual class methods like Objective-C does so it can't tell in CreateForCell which class you called it on unless you tell it with a type argument.
Related
I want to override my controllers method. Here i have overriden CreateController method of DefaultControllerFactory to return the CatalogCustomController object if request come for CatalogController.
But the problem is here that i need to pass all the dependency into controller constructor.
public class CustomControllerFactory: DefaultControllerFactory
{
public CustomControllerFactory(ICatalogModelFactory catalogModelFactory,
IProductModelFactory productModelFactory,
IControllerActivator controllerActivator, IEnumerable<IControllerPropertyActivator> propertyActivators)
:base(controllerActivator, propertyActivators)
{
this._catalogModelFactory = catalogModelFactory;
this._productModelFactory = productModelFactory;
}
public override object CreateController(ControllerContext context)
{
if (context.ActionDescriptor.ControllerTypeInfo.AsType() == typeof(CatalogController))
{
return new CatalogCustomController(_catalogModelFactory,
_productModelFactory,
_categoryService,
}
return base.CreateController(context);
}
}
While i want to do it something like this, by modifying
ControllerContext context
public override object CreateController(ControllerContext context)
{
if (context.ActionDescriptor.ControllerTypeInfo.AsType() == typeof(CatalogController))
{
context.ActionDescriptor.ControllerName = "CatalogCustomController";
}
return base.CreateController(context);
}
You could try register Controller into IServiceCollection, and then retrieve Controller from IServiceCollection in CreateController.
Extension method for AddControllersAsServices
public static class Extension
{
public static IMvcBuilder AddControllersAsServices(this IMvcBuilder builder)
{
var feature = new ControllerFeature();
builder.PartManager.PopulateFeature(feature);
foreach (var controller in feature.Controllers.Select(c => c.AsType()))
{
builder.Services.TryAddTransient(controller, controller);
}
builder.Services.Replace(ServiceDescriptor.Transient<IControllerActivator, ServiceBasedControllerActivator>());
return builder;
}
}
Register Services
services.AddMvc()
.AddControllersAsServices();
CustomControllerFactory
public class CustomControllerFactory : DefaultControllerFactory
{
public CustomControllerFactory(
IControllerActivator controllerActivator, IEnumerable<IControllerPropertyActivator> propertyActivators)
: base(controllerActivator, propertyActivators)
{
}
public override object CreateController(ControllerContext context)
{
if (context.ActionDescriptor.ControllerTypeInfo.AsType() == typeof(CatalogController))
{
return context.HttpContext.RequestServices.GetRequiredService(typeof(CatalogCustomController));
}
return base.CreateController(context);
}
}
I found a solution to do it without registering the controllers as service.
Inherit the custom controller from main one.
In custom controller factory, get the type of requested controller.
Replace the ControllerTypeInfo with the custom one
public override object CreateController(ControllerContext context)
{
Type typeOfController = context.ActionDescriptor.ControllerTypeInfo.UnderlyingSystemType;
if (typeOfController == typeof(Nop.Web.Controllers.CatalogController))
{
context.ActionDescriptor.ControllerTypeInfo = typeof(Controllers.CatalogCustomController).GetTypeInfo();
}
else if (typeOfController == typeof(Nop.Web.Areas.Admin.Controllers.ProductController))
{
context.ActionDescriptor.ControllerTypeInfo = typeof(Areas.Admin.Controllers.ProductCustomController).GetTypeInfo();
}
return base.CreateController(context);
}<pre>
I've inherited this Xamarin.Android app and it has a few issues.
A particular bug involves an ArrayAdapter<ProductListObject>, where ProductListObject is a common POCO that's shared between subprojects (i.e. Android, Windows Phone and iOS); it just has a couple of properties (e.g. an Id) and overrides the (.NET) Equals() method to achieve structural equality:
public class ProductListObject
{
public long Id { get; set; }
public override bool Equals(object obj)
{
if (!(obj is ProductListObject))
{
return false;
}
return Id == (obj as ProductListObject).Id;
}
}
The problem is that whenever I put an instance of this ProductListObject in an ArrayAdapter, I can't find it again, even if they have the same Id:
var p1 = new ProductListObject { Id = 1 };
var p2 = new ProductListObject { Id = 1 };
var areEqual = p1.Equals(p2); // returns True, as expected
var productAdapter = new ArrayAdapter<ProductListObject>(this, 0, new[] { p1 });
var position = productAdapter.GetPosition(p2); // returns -1 >:(
My question is: what do I have to do to make my POCO's work with Xamarin.Android types that rely on the Java equals() method, internally (like ArrayAdapter; which delegates to List.indexOf(Object))?
What I have tried:
verified that the corresponding Java version works as expected (it does)
overrode GetHashCode() (it doesn't matter, as I expected)
googled and checked the Xamarin documentation for information about implementing Equals() (I found nothing particularly relevant)
Thanks,
Jan
I did as Matt R suggested and created a proxy that inherits from Java.Lang.Object and delegates to the actual .NET object:
public class JavaObject<TValue> : Java.Lang.Object
{
public readonly TValue Value;
internal JavaObject(TValue value)
{
Value = value;
}
public override bool Equals(Java.Lang.Object that)
{
if (!(that is JavaObject<TValue>))
{
return false;
}
return Value.Equals((that as JavaObject<TValue>).Value);
}
public override int GetHashCode()
{
return Value.GetHashCode();
}
}
This doesn't tie my platform-agnostic POCO's to the Android implementation, plus it doesn't force me to lock into some rigid inheritance tree, which is always a plus.
Application is straightforward:
var p1 = new JavaObject<ProductListObject>(new ProductListObject { Id = 1 });
var p2 = new JavaObject<ProductListObject>(new ProductListObject { Id = 1 });
var areEqual = p1.Equals(p2); // returns True, as expected
var productAdapter = new ArrayAdapter<JavaObject<ProductListObject>>(this, 0, new[] { p1 });
var position = productAdapter.GetPosition(p2); // returns 0!
It looks like .NET objects get wrapped within a Java.Lang.Object when used inside a Android.Widget.ArrayAdapter. Therefore, the comparison method that's used in the productAdapter.GetPosition(...) call is actually the java Equals(Java.Lang.Object o) method for the wrapping Java.Lang.Object.
To make a ProductListObject resolve to the same index when two objects have the same Id, make ProductListObject derive from Java.Lang.Object, override the Equals(Java.Lang.Object) and forward it to the .NET Equals(System.Object) method:
public class ProductListObject : Java.Lang.Object
{
public long Id { get; set; }
public override bool Equals(object obj) // Inherited from System.Object.
{
if (!(obj is ProductListObject))
{
return false;
}
return Id == (obj as ProductListObject).Id;
}
public override bool Equals (Java.Lang.Object o) // Inherited from Java.Lang.Object.
{
return this.Equals (o as System.Object);
}
}
If you can't inherit ProductListObject from Java.Lang.Object, another option is to implement your own proxy class:
public class ProductListObject
{
public long Id { get; set; }
public override bool Equals(System.Object obj)
{
if (!(obj is ProductListObject))
{
return false;
}
return Id == (obj as ProductListObject).Id;
}
}
public class JavaProxy: Java.Lang.Object
{
public Object Object { get; private set; }
public JavaProxy(System.Object o)
{
Object = o;
}
public override bool Equals (Java.Lang.Object o)
{
var proxy = o as JavaProxy;
if (o != null) {
return Object.Equals (proxy.Object);
}
return base.Equals (o);
}
}
// ...
var productAdapter = new ArrayAdapter<JavaProxy>(this, 0, new[] { new JavaProxy(p1) });
var position = productAdapter.GetPosition(new JavaProxy(p2));
It's not as clean as the first approach but it also works.
I upgraded my nuget package for the Web API 2 from the RC1 to 5.0.0, and was dumbfounded to find that HttpRouteBuilder, which used to be accessible, was made internal. Along with that, there is no longer an overload for HttpConfiguration.MapHttpAttributeRoutes that takes HttpRouteBuilder as an argument. Why?
I was using that, and it solves a major problem in my project. What do I use instead?
Background:
I am writing a server that uses Attribute Routing for Web API 2. I implemented a class that inherited from HttpRouteBuilder so that I could inject a couple extra path segments to every URI. For example, if the default route builder ended up creating a route for //myserver/user/update, my route builder would modify that route to //myserver/{instance}/user/update. I wanted this done automatically so that I didn't have to stick that in every single of my hundreds of HttpGet, HttpPost, etc. attributes. So now how do I handle that with this major change?
That internalling broke something I was working on as well.
A change set made on August 21st 2013 made this api alteration to fix this issue. According to that issue the only reason functionality was removed was to make Web Api closer to MVC's api. Not a particularly good justification in my opinion.
To resolve my issues I implemented a custom IHttpActionSelector derived from ApiControllerActionSelector. I hope it is not going to be my final solution since it really is far too much code for a simple thing. This approach should work for your problem too.
In my project each route needs to be modified according to which assembly it was found in. In following simplified code every route is prefixed with /Api (before a controller's RoutePrefixAttribute if present).
The actual IHttpActionSelector:
public class PrefixWithApiControllerActionSelector : WrappingApiControllerActionSelector {
protected override HttpActionDescriptor WrapHttpActionDescriptor(HttpActionDescriptor actionDescriptor) {
if (actionDescriptor is ReflectedHttpActionDescriptor)
return new PrefixWithApiReflectedHttpActionDescriptor((ReflectedHttpActionDescriptor)actionDescriptor);
return actionDescriptor;
}
}
public abstract class WrappingApiControllerActionSelector : ApiControllerActionSelector {
protected abstract HttpActionDescriptor WrapHttpActionDescriptor(HttpActionDescriptor actionDescriptor);
public override ILookup<string, HttpActionDescriptor> GetActionMapping(HttpControllerDescriptor controllerDescriptor) {
return base.GetActionMapping(controllerDescriptor).SelectMany(grouping => {
return grouping.Select(actionDescriptor => new KeyValuePair<string, HttpActionDescriptor>(grouping.Key, WrapHttpActionDescriptor(actionDescriptor)));
}).ToLookup(_ => _.Key, _ => _.Value);
}
}
The part that changes the route:
public class PrefixWithApiHttpRouteInfoProvider : WrappedHttpRouteInfoProvider {
public PrefixWithApiHttpRouteInfoProvider(IHttpRouteInfoProvider infoProvider, HttpControllerDescriptor controllerDescriptor) : base(infoProvider, controllerDescriptor) { }
public override string Template {
get {
var parts = new List<string>();
parts.Add("Api");
var prefix = ControllerDescriptor.GetCustomAttributes<RoutePrefixAttribute>().FirstOrDefault();
if (prefix != null && !string.IsNullOrEmpty(prefix.Prefix)) {
parts.Add(prefix.Prefix);
}
if (!string.IsNullOrEmpty(InfoProvider.Template)) {
parts.Add(InfoProvider.Template);
}
var route = "~/" + string.Join("/", parts);
if (route.Length > 2 && route.EndsWith("/", StringComparison.Ordinal)) {
route = route.Substring(0, route.Length - 1);
}
return route;
}
}
}
public abstract class WrappedHttpRouteInfoProvider : IHttpRouteInfoProvider {
private readonly IHttpRouteInfoProvider _infoProvider;
private readonly HttpControllerDescriptor _controllerDescriptor;
protected WrappedHttpRouteInfoProvider(IHttpRouteInfoProvider infoProvider, HttpControllerDescriptor controllerDescriptor) {
_infoProvider = infoProvider;
_controllerDescriptor = controllerDescriptor;
}
public virtual string Name {
get { return InfoProvider.Name; }
}
public virtual string Template {
get { return _infoProvider.Template; }
}
public virtual int Order {
get { return InfoProvider.Order; }
}
protected HttpControllerDescriptor ControllerDescriptor {
get { return _controllerDescriptor; }
}
protected IHttpRouteInfoProvider InfoProvider {
get { return _infoProvider; }
}
}
The glue:
public class PrefixWithApiReflectedHttpActionDescriptor : WrappedReflectedHttpActionDescriptor {
public PrefixWithApiReflectedHttpActionDescriptor(ReflectedHttpActionDescriptor descriptor) : base(descriptor) {}
public override Collection<T> GetCustomAttributes<T>(bool inherit) {
if (typeof(T) == typeof(IHttpRouteInfoProvider)) {
var attributes = Descriptor.GetCustomAttributes<T>(inherit).Cast<IHttpRouteInfoProvider>().Select(_ => new PrefixWithApiHttpRouteInfoProvider(_, Descriptor.ControllerDescriptor));
return new Collection<T>(attributes.Cast<T>().ToList());
}
return Descriptor.GetCustomAttributes<T>(inherit);
}
public override Collection<T> GetCustomAttributes<T>() {
if (typeof(T) == typeof(IHttpRouteInfoProvider)) {
var attributes = Descriptor.GetCustomAttributes<T>().Cast<IHttpRouteInfoProvider>().Select(_ => new PrefixWithApiHttpRouteInfoProvider(_, Descriptor.ControllerDescriptor));
return new Collection<T>(attributes.Cast<T>().ToList());
}
return Descriptor.GetCustomAttributes<T>();
}
}
public abstract class WrappedReflectedHttpActionDescriptor : ReflectedHttpActionDescriptor {
private readonly ReflectedHttpActionDescriptor _descriptor;
protected WrappedReflectedHttpActionDescriptor(ReflectedHttpActionDescriptor descriptor) : base(descriptor.ControllerDescriptor, descriptor.MethodInfo) {
_descriptor = descriptor;
}
public override HttpActionBinding ActionBinding {
get { return Descriptor.ActionBinding; }
set { Descriptor.ActionBinding = value; }
}
public override Collection<T> GetCustomAttributes<T>(bool inherit) {
return Descriptor.GetCustomAttributes<T>(inherit);
}
public override Collection<T> GetCustomAttributes<T>() {
return Descriptor.GetCustomAttributes<T>();
}
public override Collection<System.Web.Http.Filters.FilterInfo> GetFilterPipeline() {
return Descriptor.GetFilterPipeline();
}
public override Collection<System.Web.Http.Filters.IFilter> GetFilters() {
return Descriptor.GetFilters();
}
public override System.Collections.Concurrent.ConcurrentDictionary<object, object> Properties {
get { return Descriptor.Properties; }
}
public override IActionResultConverter ResultConverter {
get { return Descriptor.ResultConverter; }
}
public override Collection<HttpMethod> SupportedHttpMethods {
get { return Descriptor.SupportedHttpMethods; }
}
public override Collection<HttpParameterDescriptor> GetParameters() {
return Descriptor.GetParameters();
}
public override Task<object> ExecuteAsync(HttpControllerContext controllerContext, IDictionary<string, object> arguments, CancellationToken cancellationToken) {
return Descriptor.ExecuteAsync(controllerContext, arguments, cancellationToken);
}
public override string ActionName {
get { return Descriptor.ActionName; }
}
public override Type ReturnType {
get { return Descriptor.ReturnType; }
}
protected ReflectedHttpActionDescriptor Descriptor {
get { return _descriptor; }
}
}
To use this functionality just substitute the IHttpActionSelector service with PrefixWithApiControllerActionSelector in the config.
If you find a cleaner way of doing things please post your solution!
ActionBase, ActionA, ActionB and ActionC are Entities (from a database). ActionA, ActionB and ActionC are derived type of ActionBase.
ActionB and ActionC implements ISpecialAction with a SpecialProperty.
ex :
public interface ISpecialAction
{
Guid SpecialProperty { get; }
}
public partial class ActionBase
{
public objectX OnePropertyBase { get; set; }
}
public partial class ActionA : ActionBase
{
public objectY OnePropertyA { get; set; }
}
public partial class ActionB:ActionBase,ISpecialAction
{
public objectZ OnePropertyB { get; set; }
public Guid SpecialProperty
{
get
{
return OnePropertyB.ID;
}
}
}
public partial class ActionC : ActionBase ,ISpecialAction
{
public objectW OnePropertyC { get; set; }
public Guid SpecialProperty
{
get
{
return OnePropertyC.ID;
}
}
}
My problem is that SpecialProperty is build from other Properties of the objects (ActionB or ActionC) and when the cast (to ISpecialAction) is done, OtherProperty and OtherProperty2 are null.
I tried :
GetActionBase().ToList().Where(x=>x is ISpecialAction && ((dynamic) x).SpecialProperty== p_SpecialProperty);
GetActionBase().ToList().Where(x=>x is ISpecialAction && ((ISpecialAction) x).SpecialProperty== p_SpecialProperty);
GetActionBase().ToList().OfType<ISpecialAction>().Where(x => x.SpecialProperty== p_SpecialProperty).Cast<ActionBase>();
return GetActionOnGoing().ToList().OfType<ICityAction>().Cast<ActionBase>().Where(x => ((dynamic)x).CityId == p_CityId);
remark : OfType<> doesn't works with an Interface in Linq to entities but is ok in Linq to object
How do I access my property interface without knowing the type of the object?
I might missed something but this is Ok with the code you provided :
public class objectX
{
}
public class objectY
{
}
public class objectZ
{
public Guid ID { get { return Guid.NewGuid();} }
}
public class objectW
{
public Guid ID { get { return new Guid(); } }
}
class Program
{
private static Guid p_SpecialProperty;
static void Main(string[] args)
{
var result = GetActionBase().ToList().Where(x => x is ISpecialAction && ((dynamic)x).SpecialProperty == p_SpecialProperty).FirstOrDefault();
var result1 = GetActionBase().ToList().Where(x => x is ISpecialAction && ((ISpecialAction)x).SpecialProperty == p_SpecialProperty).FirstOrDefault();
var result2 = GetActionBase().ToList().OfType<ISpecialAction>().Where(x => x.SpecialProperty == p_SpecialProperty).Cast<ActionBase>().FirstOrDefault();
}
private static IEnumerable<ActionBase> GetActionBase()
{
return new List<ActionBase> {new ActionA{OnePropertyA= new objectY()}, new ActionB{OnePropertyB=new objectZ()},new ActionC{OnePropertyC=new objectW()} };
}
}
Not sure if I exactly understand your question, but could you try using an intermediate interface, such as:
public interface ISpecialActionB : ISpecialAction
{
objectZ OnePropertyB { get; set; }
}
public class ActionB : ActionBase, ISpecialActionB
{
//same stuff
}
and casting to that instead.
var b = new ActionB{OnePropertyB = new Whatever()};
var bAsSpecial = b as ISpecialActionB;
var whatever = b.OnePropertyB; // should not be null
It' ok.
Your example run very well without problem so I searched in a other way : AutoMapper.
l_List.Actions = Mapper.Map<List<ActionBase>, Action[]>(l_ActionManagement.GetActionBySpecialId(l_Special.ID).ToList());
The problem was not interfaces or Linq queries but it was that automapper need an empty constructor and in this constructor, I need to initialize OnePropertyB and OnePropertyC to compute SpecialProperty.
Thanks
I have Some issues with the life time manager in unity, it uses the object like its singleton, but in the configuration I set it to "PerWebRequest".
The Error is:
A single instance of controller 'TestController' cannot be used to handle multiple requests. If a custom controller factory is in use, make sure that it creates a new instance of the controller for each request.
The PerWebRequest code:
public class UnityPerWebRequestLifetimeManager : LifetimeManager
{
private HttpContextBase _httpContext;
public UnityPerWebRequestLifetimeManager()
: this(new HttpContextWrapper(HttpContext.Current))
{
}
public UnityPerWebRequestLifetimeManager(HttpContextBase httpContext)
{
_httpContext = httpContext;
}
private IDictionary<UnityPerWebRequestLifetimeManager, object> BackingStore
{
get
{
_httpContext = (HttpContext.Current != null) ? new HttpContextWrapper(HttpContext.Current) : _httpContext;
return UnityPerWebRequestLifetimeModule.GetInstances(_httpContext);
}
}
private object Value
{
[DebuggerStepThrough]
get
{
IDictionary<UnityPerWebRequestLifetimeManager, object> backingStore = BackingStore;
return backingStore.ContainsKey(this) ? backingStore[this] : null;
}
[DebuggerStepThrough]
set
{
IDictionary<UnityPerWebRequestLifetimeManager, object> backingStore = BackingStore;
if (backingStore.ContainsKey(this))
{
object oldValue = backingStore[this];
if (!ReferenceEquals(value, oldValue))
{
IDisposable disposable = oldValue as IDisposable;
if (disposable != null)
{
disposable.Dispose();
}
if (value == null)
{
backingStore.Remove(this);
}
else
{
backingStore[this] = value;
}
}
}
else
{
if (value != null)
{
backingStore.Add(this, value);
}
}
}
}
[DebuggerStepThrough]
public override object GetValue()
{
return Value;
}
[DebuggerStepThrough]
public override void SetValue(object newValue)
{
Value = newValue;
}
[DebuggerStepThrough]
public override void RemoveValue()
{
Value = null;
}
}
The controller:
public class TestController : Controller
{
//
// GET: /Test/
public TestController()
{
}
public ActionResult Index()
{
return View();
}
public ActionResult RadioButtonList()
{
return View("TestControl");
}
}
The Controller Factory:
public class ControllerFactory : DefaultControllerFactory
{
protected override IController GetControllerInstance(System.Web.Routing.RequestContext requestContext, Type controllerType)
{
return (controllerType == null) ? base.GetControllerInstance(requestContext, controllerType) : IoC.Resolve<IController>(controllerType);
}
}
And in one of the views I am trying to use it like this:
...
<% Html.RenderAction<TestController>(c => c.RadioButtonList()); %>
<% Html.RenderAction<TestController>(c => c.RadioButtonList()); %>
...
I don't know what wrong here?
Thanks.
Both unity controller requests are created within the same HTTP request/reply, hence you get the same instance. You need to switch so that the controllers have a Transient lifetime.
I would switch to DependencyResolver instead of using ControllerFactory since you are running MVC3.