UWP ContentDialog调用 [英] UWP ContentDialog Invocation

问题描述

我正在使用UWP和Template 10通过遵循MVVM模式来构建GUI应用程序.作为应用程序的一部分，我需要通过按主页上的按钮来调用内容对话框.因此，为此目的在独立的.xaml文件中创建了单独的ContentDialog:

I am using UWP and Template 10 to build a GUI app by following MVVM pattern. As a part of application I need to invoke a content dialog by pressing button on Main Page. So separate ContentDialog was created in standalone .xaml file for that purpose:

<ContentDialog
    x:Class="UWP1.Views.Speech"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:UWP1.Views"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    Title="Dictate"
    PrimaryButtonText="Accept"
    SecondaryButtonText="Cancel"
    PrimaryButtonClick="ContentDialog_PrimaryButtonClick"
    SecondaryButtonClick="ContentDialog_SecondaryButtonClick"
    >
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="auto"/>
            <RowDefinition Height="auto"/>
            <RowDefinition Height="auto"/>
            <RowDefinition Height="auto"/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="150" />
            <ColumnDefinition Width="150" />
        </Grid.ColumnDefinitions>
            <Button Margin="15" Content="Dictate" Grid.Row="0" Grid.Column="0" HorizontalAlignment="Stretch"/>
        <Button  Margin="15" Content="Clear Text" Grid.Row="0" Grid.Column="1" HorizontalAlignment="Stretch"/>
        <TextBlock Grid.Row="1" Grid.ColumnSpan="2" Text="Tap 'Dictate', and speak" FontSize="12" />
            <TextBlock Margin="0 10 0 0" Grid.Row="2" Grid.ColumnSpan="2" Text="Message Dication" HorizontalAlignment="Center" FontSize="24"  />
        <ScrollViewer Grid.Row="3" Grid.ColumnSpan="2" Height="300">
            <TextBox Margin="5 5 5 10"  AcceptsReturn="True"  />
        </ScrollViewer>
    </Grid>
</ContentDialog>

通过按按钮在我的主页中打开/调用它的正确方法是什么(因为我需要将视图和视图模型的逻辑分开)?

What is the proper way to open/invoke it in my Main Page by pressing button (as I need to keep logic separated for view and viewmodel)?

我现在如何做:

我从主页调用DictateCommand，后者又创建了ContentDialog的实例并显示它:

From Main Page I invoke DictateCommand, which in turn creates an instance of ContentDialog and shows it:

 <AppBarButton Grid.Column="1" Icon="Microphone" IsCompact="True" HorizontalAlignment="Right" Command="{Binding DictateCommand}"/>

        public ICommand DictateCommand { get; set; }

        public async void Dictate(object obj)
        {
            var contentDialog = new Speech();
            await contentDialog.ShowAsync();
        }

对我来说，这似乎是MVVM模式违规.您能帮我按正确的方式做吗?

It looks like a MVVM pattern breach for me. Could you please help me to do it in a right way?

我已经实现了对话框服务并将其注入到主视图模型中. 但是，我遇到了另一个障碍.对于此对话框，我创建了单独的视图模型和属性，该模型和属性封装了对话框文本框的值.当我在对话框上按接受"按钮时-我需要此值反映在我的主视图中.因此，我需要将对话框的文本框值从对话框的视图模型传递到主视图模型.我是否应该执行另一个依赖项注入来处理它?<​​/p>

I have implemented dialog service and injected it in the main view model. However, I got another obstacle. For this dialog I created separate view model and property which encapsulates dialog text box value. When I press 'accept' button on the dialog - I need this value to be reflected on my Main View. So I need to pass dialog's text box value from dialog's view model to main view model. Should I perform another dependency injection to deal with it?

推荐答案

您有四个选择.

一个第一个是服务，就像@ Ask-too-much的解释一样.实际上，如果您愿意，这是一个很好的解决方案.

ONE The first is a service, just like @Ask-too-much explains. In fact, this is a beautiful solution if you like it.

第一个解决方案的好处是可重用.老实说，如果您不重用此UI，那么专用服务可能会过头了.

The benefits of the first solution are that it is reusable. If you are not reusing this UI, a dedicated service might be overkill, to be honest.

两个第二个是视图模型事件.也就是说，您的Page可以订阅您的视图模型的事件(我们将其称为ShowContentDialog)，当视图模型引发该事件时，您的Page会处理其演示文稿.

TWO The second is a view-model event. That is to say, your Page can subscribe to your view-model's event (let's call it ShowContentDialog) and when it is raised by the view-model, your Page handle its presentation.

这种方法的好处在于，就像第一种方法一样，您将工作分担给另一个班级.在这种情况下，您将创建一种可能的一次性解决方案，而不需要服务，服务接口或以某种方式注入该服务.如果您不等事件的结果，那么对于您这样的99％的问题，我认为这是个好主意.

The benefits this approach is that, just like the first approach, you are offloading the effort to another class. In this case, you are creating what is likely a one-off solution without needing a service, a service interface, or injection of that service somehow. If you are not waiting for the result of the event, then I think this is idea for 99% of issues like yours.

三第三种方法是使用可以绑定到属性的其他控件.例如，由于您已经在使用模板10，因此可以使用具有IsModal属性的ModalDialog控件.视图模型中的属性(我们称其为IsModalVisible)可用于控制对话框而无需与之耦合.

THREE The third approach is to use a different control that can be bound to a property. For example, since you are already using Template 10, you can use the ModalDialog control which has an IsModal property. A property in your view-model (let's call it IsModalVisible) can be used to control the dialog without coupling to it.

好的一面是，您可以从视图模型的逻辑中调用对话框，就像前两种方法一样.但是与第一个不同，您不需要服务.与第二种方法不同，您不需要处理程序.这是最数据绑定"的方式，也是我可能要做的.

The good part of this is that you get to invoke the dialog from the logic of your view-model, just like the first two approaches. But unlike the first, you do not need a service. Unlike the second, you do not need a handler. It's the most "data binding" way to do it, and likely what I would do.

四个第四种方法是使用消息传递.消息传递是一种视图模型用于与另一视图模型进行通信的机制.在这种情况下，您可以使用来自视图模型的消息传递(带有一条消息，我们可能将其称为ShowDialog)，该消息传递不是在另一个视图模型中而是在您的Page中侦听的.这也可以.

FOUR The fourth way to do it is to use messaging. Messaging is the mechanism one view-model uses to communicate with another. IN this case you could use messaging from your view-model (with a message we might call ShowDialog) that is listened for, not in another view-model, but in your Page. This would work fine, too.

不利的一面是您需要一个消息传递解决方案，但是您可能已经拥有了.有利的一面是，随着消息传递被多播给正在收听的任何人，可以随时重新定位用于处理视觉效果的逻辑.

The down side to this is that you need a messaging solution, but you might already have that. The up-side is that the logic for handling the visual could be relocated at any time as Messaging is multicasted to anyone listening.

如果我是你，也许我会考虑第三个.如果不多了解您的应用场景，就不能确定.但是，您是一名开发人员.所有这四个选项都是好的.只要确保不要试图将UIElement传递到您的视图模型中.那是不必要的烦恼:)

If I were you, I would consider number 3 first, perhaps. Without a little more understanding of your app scenario, I can't be sure. You are a developer, though. All four of those options are good. Just be sure not to be tempted into passing the UIElement into your view-model. That's needless nastiness :)

祝你好运！

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