从PRISM开始学WPF（九）交互（完结）

0x07交互

Notification

xaml:

<Window x:Class="UsingPopupWindowAction.Views.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
        xmlns:prism="http://prismlibrary.com/"
        prism:ViewModelLocator.AutoWireViewModel="True"
        Title="{Binding Title}" Height="350" Width="525">
    <i:Interaction.Triggers>
        <prism:InteractionRequestTrigger SourceObject="{Binding NotificationRequest}">
            <prism:PopupWindowAction IsModal="True" CenterOverAssociatedObject="True" />
        </prism:InteractionRequestTrigger>
    </i:Interaction.Triggers>
    <StackPanel>
        <Button Margin="5" Content="Raise Default Notification" Command="{Binding NotificationCommand}" />

        <TextBlock Text="{Binding Title}" Margin="25" HorizontalAlignment="Center" FontSize="24" />
    </StackPanel>
</Window>

code-behind:

using Prism.Commands;
using Prism.Interactivity.InteractionRequest;
using Prism.Mvvm;

namespace UsingPopupWindowAction.ViewModels
{
    public class MainWindowViewModel : BindableBase
    {
        private string _title = "Prism Unity Application";
        public string Title
        {
            get { return _title; }
            set { SetProperty(ref _title, value); }
        }

        public InteractionRequest<INotification> NotificationRequest { get; set; }
        public DelegateCommand NotificationCommand { get; set; }

        public MainWindowViewModel()
        {
            NotificationRequest = new InteractionRequest<INotification>();
            NotificationCommand = new DelegateCommand(RaiseNotification);
        }

        void RaiseNotification()
        {
            NotificationRequest.Raise(new Notification { Content = "Notification Message", Title = "Notification" }, r => Title = "Notified");
        }
    }
}

Prism通过InteractionRequest 来实现Pop Up window。

xaml中需要注册一个Trigger：

    <i:Interaction.Triggers>
        <prism:InteractionRequestTrigger SourceObject="{Binding NotificationRequest}">
            <prism:PopupWindowAction IsModal="True" CenterOverAssociatedObject="True" />
        </prism:InteractionRequestTrigger>
    </i:Interaction.Triggers>

code-behind中声明

        public InteractionRequest<INotification> NotificationRequest { get; set; }

在command的回调函数中就可以使用NotificationRequest：

            NotificationRequest.Raise(new Notification { Content = "Notification Message", Title = "Notification" }, r => Title = "Notified");

Confirmation

跟Notification的使用方法一样，先注册：

        <prism:InteractionRequestTrigger SourceObject="{Binding ConfirmationRequest}">
            <prism:PopupWindowAction IsModal="True" CenterOverAssociatedObject="True" />
        </prism:InteractionRequestTrigger>

然后在使用InteractionRequest的时候：

        public InteractionRequest<IConfirmation> ConfirmationRequest { get; set; }

callback:

            ConfirmationRequest.Raise(new Confirmation {
                Title = "Confirmation",
                Content = "Confirmation Message" },
                r => Title = r.Confirmed ? "Confirmed" : "Not Confirmed");

CustomPopupRequest

简单客制化弹窗（这里我们并没有用到viewmodel）

首先绘制一个弹窗：

<UserControl x:Class="UsingPopupWindowAction.Views.CustomPopupView"
             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:local="clr-namespace:UsingPopupWindowAction.Views"
             mc:Ignorable="d"
             d:DesignHeight="300" d:DesignWidth="300">
    <Grid>
        <StackPanel>
            <TextBlock Text="{Binding Title}" FontSize="24" HorizontalAlignment="Center" />
            <TextBlock Text="{Binding Content}" Margin="10"/>
            <Button Margin="25" Click="Button_Click">Accept</Button>
        </StackPanel>
    </Grid>
</UserControl>

code-behind：

using Prism.Interactivity.InteractionRequest;
using System;
using System.Windows;
using System.Windows.Controls;

namespace UsingPopupWindowAction.Views
{
    /// <summary>
    /// Interaction logic for CustomPopupView.xaml
    /// </summary>
    public partial class CustomPopupView : UserControl, IInteractionRequestAware
    {
        public CustomPopupView()
        {
            InitializeComponent();
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            FinishInteraction?.Invoke();
        }

        public Action FinishInteraction { get; set; }
        public INotification Notification { get; set; }
    }
}

然后在调用者的xaml中注册：

        <prism:InteractionRequestTrigger SourceObject="{Binding CustomPopupRequest}">
            <prism:PopupWindowAction IsModal="True" CenterOverAssociatedObject="True">
                <prism:PopupWindowAction.WindowContent>
                    <views:CustomPopupView />
                </prism:PopupWindowAction.WindowContent>
            </prism:PopupWindowAction>
        </prism:InteractionRequestTrigger>

code-behind:

        public InteractionRequest<INotification> CustomPopupRequest { get; set; }
        public DelegateCommand CustomPopupCommand { get; set; }

call-back:

            CustomPopupRequest.Raise(new Notification { Title = "Custom Popup", Content = "Custom Popup Message " }, r => Title = "Good to go");

复杂的客制化弹框：

上面的弹窗中，只有一个 accept按钮，在prism内置的confirmation都可以实现是和否，那客制化的弹窗中如何实现更为复杂的情况呢？

示例中实现了一个弹窗，然后选择一个类型为String的Item确认后并将他返回给调用者，如没有确认，则提示没有选择。

定义一个接口(为了IoC）：

using Prism.Interactivity.InteractionRequest;

namespace UsingPopupWindowAction.Notifications
{
    public interface ICustomNotification : IConfirmation
    {
        string SelectedItem { get; set; }
    }
}

一个类（真正干活的类）：

using Prism.Interactivity.InteractionRequest;
using System.Collections.Generic;

namespace UsingPopupWindowAction.Notifications
{
    public class CustomNotification : Confirmation, ICustomNotification
    {
        public IList<string> Items { get; private set; }

        public string SelectedItem { get; set; }

        public CustomNotification()
        {
            this.Items = new List<string>();
            this.SelectedItem = null;

            CreateItems();
        }

        private void CreateItems()
        {
            Items.Add("Item1");
            Items.Add("Item2");
            Items.Add("Item3");
            Items.Add("Item4");
            Items.Add("Item5");
            Items.Add("Item6");
        }
    }
}

调用者xaml中注册:

        <prism:InteractionRequestTrigger SourceObject="{Binding CustomNotificationRequest}">
            <prism:PopupWindowAction IsModal="True" CenterOverAssociatedObject="True">
                <prism:PopupWindowAction.WindowContent>
                    <views:ItemSelectionView />
                </prism:PopupWindowAction.WindowContent>
            </prism:PopupWindowAction>
        </prism:InteractionRequestTrigger>

调用者Code-behind：

        public InteractionRequest<ICustomNotification> CustomNotificationRequest { get; set; }
        public DelegateCommand CustomNotificationCommand { get; set; }

            CustomNotificationRequest = new InteractionRequest<ICustomNotification>();
            CustomNotificationCommand = new DelegateCommand(RaiseCustomInteraction);

        private void RaiseCustomInteraction()
        {
            CustomNotificationRequest.Raise(new CustomNotification { Title = "Custom Notification" }, r =>
                {
                    if (r.Confirmed && r.SelectedItem != null)
                        Title = $"User selected: { r.SelectedItem}";
                    else
                        Title = "User cancelled or didn't select an item";
                });
        }

接下来是我们的弹窗：

<UserControl x:Class="UsingPopupWindowAction.Views.ItemSelectionView"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:prism="http://prismlibrary.com/"
             prism:ViewModelLocator.AutoWireViewModel="True"
             Width="400">
    <StackPanel>

        <TextBlock FontSize="24" Foreground="DarkBlue" Margin="10">Item Selection</TextBlock>

        <TextBlock Margin="10" TextWrapping="Wrap">
                This view has its own view model that implements the <Bold>IInteractionRequestAware</Bold> interface.
                Thanks to this, the view model is automatically populated with the corresponding "notification"
                and an action to finish the interaction, which in this case closes the window.
        </TextBlock>

        <TextBlock Margin="10" TextWrapping="Wrap" FontWeight="Bold">Please select an item:</TextBlock>
        <ListBox SelectionMode="Single" Margin="10,0" Height="100" ItemsSource="{Binding Notification.Items}" SelectedItem="{Binding SelectedItem, Mode=TwoWay}"></ListBox>

        <Grid>
            <Grid.ColumnDefinitions>
                <ColumnDefinition />
                <ColumnDefinition />
            </Grid.ColumnDefinitions>

            <Button AutomationProperties.AutomationId="ItemsSelectButton" Grid.Column="0" Margin="10" Command="{Binding SelectItemCommand}">Select Item</Button>
            <Button AutomationProperties.AutomationId="ItemsCancelButton" Grid.Column="1" Margin="10" Command="{Binding CancelCommand}">Cancel</Button>
        </Grid>
    </StackPanel>
</UserControl>

code-behind:

using Prism.Commands;
using Prism.Interactivity.InteractionRequest;
using Prism.Mvvm;
using System;
using UsingPopupWindowAction.Notifications;

namespace UsingPopupWindowAction.ViewModels
{
    public class ItemSelectionViewModel : BindableBase, IInteractionRequestAware
    {
        public string SelectedItem { get; set; }

        public DelegateCommand SelectItemCommand { get; private set; }

        public DelegateCommand CancelCommand { get; private set; }

        public ItemSelectionViewModel()
        {
            SelectItemCommand = new DelegateCommand(AcceptSelectedItem);
            CancelCommand = new DelegateCommand(CancelInteraction);
        }

        private void CancelInteraction()
        {
            _notification.SelectedItem = null;
            _notification.Confirmed = false;
            FinishInteraction?.Invoke();
        }

        private void AcceptSelectedItem()
        {
            _notification.SelectedItem = SelectedItem;
            _notification.Confirmed = true;
            FinishInteraction?.Invoke();
        }

        public Action FinishInteraction { get; set; }

        private ICustomNotification _notification;

        public INotification Notification
        {
            get { return _notification; }
            set { SetProperty(ref _notification, (ICustomNotification)value); }
        }

    }
}