Prism 自定义确认交互

Question

我使用 Prism Unity、WPF 和 Mvvm 在应用程序中创建了一个自定义确认窗口。我需要有关需要发送回视图模型的通知的帮助。我在详细记录视图中有这个，我们称之为 MyDetailView。

<!-- Custom Confirmation Window -->
<ie:Interaction.Triggers>
  <interactionRequest:InteractionRequestTrigger 
       SourceObject="{Binding ConfirmationRequest, Mode=TwoWay}">
     <mycontrols:PopupWindowAction1 IsModal="True"/>
  </interactionRequest:InteractionRequestTrigger>
</ie:Interaction.Triggers>

如上图，我设置了交互Mode=TwoWay，这样确认弹窗就可以返回OK或者Cancel按钮的点击结果。确认窗口按原样出现，但我不知道如何将按钮单击结果发送回我的视图模型，比如 MyDetailViewModel。这是主要问题。

编辑：这是引发 InteractionRequest 的 MyDetailViewMmodel 方法。

private void RaiseConfirmation()
{ConfirmationRequest
    .Raise(new Confirmation()
    {
        Title = "Confirmation Popup",
        Content = "Save Changes?"
    },  c =>{if (c.Confirmed)
{ UoW.AdrTypeRos.Submit();}

这是 PopupWindowAction1 类。这个问题的部分答案可能是我如何实现 Notification 和 FinishedInteraction 方法。

class PopupWindowAction1 : PopupWindowAction, IInteractionRequestAware
{
    protected override Window GetWindow(INotification notification)
    { // custom metrowindow using mahapps
        MetroWindow wrapperWindow = new ConfirmWindow1();
        wrapperWindow.DataContext = notification;
        wrapperWindow.Title = notification.Title;

        this.PrepareContentForWindow(notification, wrapperWindow);

        return wrapperWindow;
    }

    public INotification Notification
    {
        get { throw new NotImplementedException(); }
        set { throw new NotImplementedException(); }
    }

    public Action FinishInteraction
    {
        get { throw new NotImplementedException(); }
        set { throw new NotImplementedException(); }
    }
}

我需要在我的 ConfirmWindow1 中进行一些交互吗？

<i:Interaction.Triggers>
  <i:EventTrigger EventName="PreviewMouseLeftButtonUp">
    <ei:CallMethodAction 
      TargetObject="{Binding RelativeSource={RelativeSource AncestorType=UserControl}, 
        Path=DataContext}"
      MethodName="DataContext.ValidateConfirm"/>
  </i:EventTrigger>
</i:Interaction.Triggers>

我什至需要在按钮中进行这种类型的交互吗？如果是这样，我如何编写它需要的代码，以便它对应于调用交互的特定视图模型。有什么建议么？谢谢。

Answer 1

主要的是，当您提出交互时，提供一个在交互完成时触发的回调。此回调会返回通知，并且您的交互应该已将所有可能感兴趣的返回值存储在那里。

这是一个例子......

ViewModel 的相关部分：

public InteractionRequest<SelectQuantityNotification> SelectQuantityRequest
{
    get;
}

// in some handler that triggers the interaction
SelectQuantityRequest.Raise( new SelectQuantityNotification { Title = "Load how much stuff?", Maximum = maximumQuantity },
    notification =>
    {
        if (notification.Confirmed)
            _worldStateService.ExecuteCommand( new LoadCargoCommand( sourceStockpile.Stockpile, cartViewModel.Cart, notification.Quantity ) );
    } );

...从视图中：

<i:Interaction.Triggers>
    <interactionRequest:InteractionRequestTrigger 
        SourceObject="{Binding SelectQuantityRequest, Mode=OneWay}">
        <framework:FixedSizePopupWindowAction>
            <interactionRequest:PopupWindowAction.WindowContent>
                <views:SelectSampleDataForImportPopup/>
            </interactionRequest:PopupWindowAction.WindowContent>
        </framework:FixedSizePopupWindowAction>
    </interactionRequest:InteractionRequestTrigger>
</i:Interaction.Triggers>

此外，我们需要一个类来保存传递的数据，以及一个用于交互本身的 ViewModel/View 对。

这是数据保存类（注意 Maximum 被传递到交互，Quantity 从它返回）：

internal class SelectQuantityNotification : Confirmation
{
    public int Maximum
    {
        get;
        set;
    }

    public int Quantity
    {
        get;
        set;
    }
}

这是交互弹窗的视图：

<UserControl x:Class="ClientModule.Views.SelectSampleDataForImportPopup"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
         xmlns:prism="http://prismlibrary.com/"
         prism:ViewModelLocator.AutoWireViewModel="True"
         mc:Ignorable="d" 
         d:DesignHeight="300" d:DesignWidth="300">
    <StackPanel Orientation="Vertical">
        <TextBlock>
            Amount: <Run Text="{Binding Quantity}"/>
        </TextBlock>
        <Slider Orientation="Horizontal" Minimum="0" Maximum="{Binding Maximum}" Value="{Binding Quantity}" TickPlacement="BottomRight"/>
        <Button Content="Ok" Command="{Binding OkCommand}"/>
    </StackPanel>
</UserControl>

它是 ViewModel：

internal class SelectSampleDataForImportPopupViewModel : BindableBase, IInteractionRequestAware
{
    public SelectSampleDataForImportPopupViewModel()
    {
        OkCommand = new DelegateCommand( OnOk );
    }

    public DelegateCommand OkCommand
    {
        get;
    }

    public int Quantity
    {
        get { return _notification?.Quantity ?? 0; }
        set
        {
            if (_notification == null)
                return;
            _notification.Quantity = value;
            OnPropertyChanged( () => Quantity );
        }
    }

    public int Maximum => _notification?.Maximum ?? 0;

    #region IInteractionRequestAware
    public INotification Notification
    {
        get { return _notification; }
        set
        {
            SetProperty( ref _notification, value as SelectQuantityNotification );
            OnPropertyChanged( () => Maximum );
            OnPropertyChanged( () => Quantity );
        }
    }

    public Action FinishInteraction
    {
        get;
        set;
    }
    #endregion

    #region private
    private SelectQuantityNotification _notification;

    private void OnOk()
    {
        if (_notification != null)
            _notification.Confirmed = true;
        FinishInteraction();
    }
    #endregion
}