WPF棱镜vs mvvm灯 [英] prism vs mvvm light for wpf
问题描述
我们正在使用MVVM项目启动WPF，并且必须决定PRISM或MVVM Light(这两个框架都是我的新手).我已经阅读了一些帖子，但仍然有一些问题.有人可以从以下几个方面阐明一些观点吗?这两个框架?
We are starting a WPF with MVVM project and have to decide on PRISM or MVVM Light (I am new to both these frameworks). I have read through a few posts but still have a few questions. Can someone please throw some light on the following aspects w.r.t. both the frameworks?:
-
性能:由于任何原因，一个框架的性能是否会优于另一个?
Performance: Will either one framework perform better than the other for any reason?
应用程序内的通信(视图模型到视图模型或模块之间等):我已阅读到MVVM Light具有Messenging Service，该服务似乎也很简单.但是PRISM似乎没有任何等效的东西.真的吗? PRISM如何处理互动?
Communication within the app (viewmodel to viewmodel or between modules etc): I have read that MVVM Light has Messenging Service which appears to be fairly easy as well. But PRISM does not appear to have any equivalent. Is that true? How would PRISM handle interactions?
单元测试:已阅读PRISM更好地支持单元测试.我们还能在MVVM Light中编写NUNIT或VSTS测试吗?
Unit Testing: Have read that PRISM supports Unit Testing better. Can we still write NUNIT or VSTS tests in MVVM Light also?
推荐答案
-
我刚刚将一个项目从Prism移到了MvvmLight，它的工作速度似乎更快(非常主观).
I just moved a project from Prism to MvvmLight and it seems to work faster (very subjective).
Prism和MvvmLight都具有Mediator实现(Prism中的IEventAggregator，MvvmLight中的IMessenger).但是与IEventAggregator相比，IMessenger具有更多的功能(例如，使用令牌发送消息)，并且使用起来更加方便(请参阅下一项).
Both Prism and MvvmLight have Mediator realisation (IEventAggregator in Prism, IMessenger in MvvmLight). But IMessenger has more abilities (for instance, sending messages with tokens) compared to IEventAggregator and is much more convenient to use (see next item).
MvvmLight还具有功能更强大的ViewModelBase类.
MvvmLight also has a more powerful ViewModelBase class.
使用MvvmLight的应用程序比使用Prism的应用程序易于测试.例如，IMessenger比IEventAggregator更易于模拟.
Applications that use MvvmLight are much easier to test than those that use Prism. For instance, IMessenger is easier to mock than IEventAggregator.
PrismViewModel.cs
PrismViewModel.cs
using System;
using Microsoft.Practices.Prism.Events;
using Microsoft.Practices.Prism.ViewModel;
// An ugly empty event class
public class StringEvent : CompositePresentationEvent<string> { }
public sealed class PrismViewModel : NotificationObject
{
private readonly IEventAggregator _eventAggregator;
private string _name;
public PrismViewModel(IEventAggregator eventAggregator)
{
if (eventAggregator == null)
throw new ArgumentNullException("eventAggregator");
_eventAggregator = eventAggregator;
_eventAggregator.GetEvent<StringEvent>().Subscribe(s => Name = s);
}
public string Name
{
get { return _name; }
set
{
// boiler-plate code
if (value == _name)
return;
_name = value;
RaisePropertyChanged(() => Name);
}
}
public void SendMessage(string message)
{
_eventAggregator.GetEvent<StringEvent>().Publish(message);
}
}
PrismViewModelTestCase.cs
PrismViewModelTestCase.cs
using System;
using FluentAssertions;
using Microsoft.Practices.Prism.Events;
using NSubstitute;
using NUnit.Framework;
public class PrismViewModelTestCase
{
private static PrismViewModel CreateViewModel(IEventAggregator eventAggregator = null)
{
// You can't return Substitute.For<IEventAggregator>()
// because it returns null when PrismViewModel's constructor
// invokes GetEvent<StringEvent>() method which leads to NullReferenceException
return new PrismViewModel(eventAggregator ?? CreateEventAggregatorStub());
}
private static IEventAggregator CreateEventAggregatorStub()
{
var eventAggregatorStub = Substitute.For<IEventAggregator>();
eventAggregatorStub.GetEvent<StringEvent>().Returns(Substitute.For<StringEvent>());
return eventAggregatorStub;
}
[Test]
public void Constructor_WithNonNullEventAggregator_ExpectedSubscribesToStringEvent()
{
// Arrange
var stringEventMock = Substitute.For<StringEvent>();
var eventAggregatorStub = Substitute.For<IEventAggregator>();
eventAggregatorStub.GetEvent<StringEvent>().Returns(stringEventMock);
// Act
CreateViewModel(eventAggregatorStub);
// Assert
// With constrained isolation framework you can only mock virtual members
// CompositePresentationEvent<TPayload> has only one virtual Subscribe overload with four parameters
stringEventMock.Received()
.Subscribe(Arg.Any<Action<string>>(), Arg.Any<ThreadOption>(), Arg.Any<bool>(),
Arg.Any<Predicate<string>>());
}
[Test]
public void Name_ExpectedRaisesPropertyChanged()
{
var sut = CreateViewModel();
sut.MonitorEvents();
sut.Name = "any-value";
sut.ShouldRaisePropertyChangeFor(vm => vm.Name);
}
[Test]
public void SendMessage_ExpectedPublishesStringEventThroughEventAggregator()
{
// Arrange
var stringEventMock = Substitute.For<StringEvent>();
var eventAggregatorStub = Substitute.For<IEventAggregator>();
eventAggregatorStub.GetEvent<StringEvent>().Returns(stringEventMock);
var sut = CreateViewModel(eventAggregatorStub);
const string expectedPayload = "any-string-payload";
// Act
sut.SendMessage(expectedPayload);
// Assert
stringEventMock.Received().Publish(expectedPayload);
}
}
MvvmLightViewModel.cs
MvvmLightViewModel.cs
using System;
using GalaSoft.MvvmLight;
using GalaSoft.MvvmLight.Messaging;
public sealed class MvvmLightViewModel : ViewModelBase
{
private string _name;
public MvvmLightViewModel(IMessenger messenger)
{
if (messenger == null)
throw new ArgumentNullException("messenger");
// ViewModelBase already have field for IMessenger
MessengerInstance = messenger;
MessengerInstance.Register<string>(this, s => Name = s);
}
public string Name
{
get { return _name; }
set { Set(() => Name, ref _name, value); // Chic! }
}
public void SendMessage(string message)
{
MessengerInstance.Send(message);
}
}
MvvmLightViewModelTestCase.cs
MvvmLightViewModelTestCase.cs
using System;
using FluentAssertions;
using GalaSoft.MvvmLight.Messaging;
using NSubstitute;
using NUnit.Framework;
public class MvvmLightViewModelTestCase
{
private static MvvmLightViewModel CreateViewModel(IMessenger messenger = null)
{
return new MvvmLightViewModel(messenger ?? Substitute.For<IMessenger>());
}
[Test]
public void Constructor_WithNonNullMessenger_ExpectedRegistersToStringMessage()
{
var messengerStub = Substitute.For<IMessenger>();
var sut = CreateViewModel(messengerStub);
messengerStub.Received().Register(sut, Arg.Any<Action<string>>());
}
[Test]
public void Name_ExpectedRaisesPropertyChanged()
{
var sut = CreateViewModel();
sut.MonitorEvents();
sut.Name = "any-value";
sut.ShouldRaisePropertyChangeFor(vm => vm.Name);
}
[Test]
public void SendMessage_ExpectedSendsStringMessageThroughMessenger()
{
var messengerMock = Substitute.For<IMessenger>();
var sut = CreateViewModel(messengerMock);
const string expectedMessage = "message";
sut.SendMessage(expectedMessage);
messengerMock.Received().Send(expectedMessage);
}
}
棱镜的缺点:
-
这是一个非完全开源项目(Prism官方存储库为只读)- 2015-10-30 :现在它已完全开源: https://github.com/PrismLibrary/Prism
it's non fully open-source project (official Prism repository is read-only)- 2015-10-30: now it's fully open-sourced: https://github.com/PrismLibrary/Prism
- 2015-10-30 :Prism的新版本: https://github. com/PrismLibrary/Prism
- 2015-10-30: new version of Prism: https://github.com/PrismLibrary/Prism
我认为任何新项目都应基于现代解决方案和方法. 恕我直言，任何现代MVVM框架(例如Catel，Caliburn.Micro，MvvmLight，ReactiveUI)都比Prism好得多.
I think that any new project should be based on modern solutions and approaches. IMHO, any modern MVVM-framework (like Catel, Caliburn.Micro, MvvmLight, ReactiveUI) is much better than Prism.
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