Question

Technologies

C# 4.0
Prism 4 with Unity for DI
WPF
MVVM

Preface

我的解决办法有两个项目:MyApp.Shell和MyApp.ModuleFoo。

MyApp.Shell s Unity Boots Capper

protected override IModuleCatalog CreateModuleCatalog()
{
    // Module assemblies are read from a directory.
    DirectoryModuleCatalog moduleCatalog = new DirectoryModuleCatalog();
    moduleCatalog.ModulePath = @".Modules";
    return moduleCatalog;
}

项目MyApp.ModuleFoo载有观点和观点模式。

www.un.org/Depts/DGACM/index_spanish.htm The ViewModel

// Somehow, Unity sees this class and registers the type.
public class FooViewModel : ViewModelBaseClass
{
    public string FooText
    {
        get { return "Foo!"; }
    }
}

www.un.org/Depts/DGACM/index_spanish.htm The View

<Label Content={Binding FooText} />

www.un.org/Depts/DGACM/index_spanish.htm The View s Code-behind

// Unity automatically sees this as Constructor Injection, 
// which is exactly what I desire.
public FooView(FooViewModel viewModel)
{
    DataContext = viewModel;
    ...
}

<>MyApp.Foo Module s initialization

也许向地区管理人员登记FooView无意中向团结组织登记FooViewModel?

public void Initialize()
{
    var regionManager = ServiceLocator.Current.GetInstance<IRegionManager>();
    regionManager.RegisterViewWithRegion("FooRegion", typeof(FooView));
}

The view correctly displays "Foo!".

Problems

How do I tell Unity to register only a single instance of FooViewModel?
Additionally, (and I m thinking ahead here), how would I tell unity not to register FooViewModel?

Thanks for the help.

Edit:

添加MyApp.Foo Module 初步化法

Edit (Solution):

It turns out RegisterViewWithRegion has two overloads. From Prism s documentation, when the overload I m using is used, a new instance of the view is created. I m assuming this also creates a new instance of FooViewModel.

The other overload uses a delegate to resolve FooView. The documentation says this overload is used in the "ViewModel-first" approach. I m going to make this question as answered, but if anyone has any additional insight, I d love to hear.

Answer 1

// Somehow, Unity sees this class and registers the type. public class FooViewModel : ViewModelBaseClass ...

我感到惊讶的是,你说这番话,因为团结组织没有在集装箱内按违约登记类型。你们必须告诉我们,无论从方案上还是从编织文件中都这样做。

When you have concrete classes (not interfaces) they will automatically get created by Unity whether they are registered or not. If not the default behavior is to create a new instance each time. No lifetime management is applied also.

As far as your questions:

在你刚刚开始的单元中只登记一种类型。

Container.RegisterType<FooViewModel>(new ContainerControlledLifetimeManager());

终身管理人员将指示团结,只创造一种观点模式。

Technologies

Preface

Problems

Edit:

Edit (Solution):

友情链接