在WPF中，从单独的类访问XAML文件中实例化的控件？

Question

We have a class in our WPF project that we want to access a control that is put into a XAML file. I have put my code below and file structure to help with my question.

Folder Structure: Navigation Directors\\ FullKioskDirector.cs

MasterTemplates \\ SellAllKioskMaster.xaml

Views \\ Pages \\ PageTemplates \\ PageAttractScreen.xaml

We want 'FullKioskDirector.cs' to access the visibility of 'PageAttractScreen.xaml'. The 'SellAllKioskMaster.xaml' is referencing the 'PageAttractScreen.xaml' in its XAML.

Here is our code below.

SellAllKioskMaster.xaml

<UserControl
         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:UserControls="clr-namespace:Kiosk.Views.Pages.UserControls" xmlns:PageTemplates="clr-namespace:Kiosk.Views.Pages.PageTemplates" x:Class="Kiosk.MasterTemplates.MyContainer" 
         mc:Ignorable="d" 
         d:DesignHeight="1049" d:DesignWidth="1912" Background="White">
  <Grid>
    <!--I need to access the visibility of these elements from the 'FullKioskDirector.cs'-->
     <PageTemplates:PageAttractScreen x:Name="pageAttract" Margin="0,100"/>
     <PageTemplates:PageWelcomeScreen x:Name="pageWelcome" Margin="0,100"/>
    <PageTemplates:PageProductsScreen x:Name="pageProducts" Margin="0,100"/>
   </Grid>
 </UserControl>

FullKioskDirector.cs

 using System;
 using System.Windows;
 using System.Windows.Controls;
 using Kiosk.Common.Common.Contracts;
 using Kiosk.Views.Pages.UserControls;

 namespace Kiosk.Directors
 {
     public class FullKioskDirector : IPageNavigation
     {
         public FullKioskDirector()
         {
         /*
        Want to control visibility of my controls that are placed and 
       x:Named in the SellAllKioskMaster.xaml
         */
         }

How can I accomplish this?

Answer 1

It's better if you do it in an MVVM approach, rather than doing everything from code behind.

Nevertheless, wherever you are creating FullKioskDirector , just pass in pageAttract to the constructor.

Assuming you create the FullKioskDirector at UserControl 's constructor

public UserControl()
{
  var fullKioskDirector = new FullKioskDirector(pageAttract);
}

Then you can use it like this

public FullKioskDirector(PageAttractScreen pageAttract)
{
   pageAttract.Visibility = Visibility.Collapsed;
}

Answer 2

I would use a Publish / Subscribe pattern.

Example: MessageBus / EventAggregator

This is my tool of choice when dealing with dependency challenges.

Essentially, you just post a message for subscribers to react to. In this case your subscriber will then post a response in the form of a control.

You can leverage Bizmonger.Patterns to get the MessageBus.

https://msdn.microsoft.com/en-us/library/ff921122.aspx