Design Pattern advice

Question

Hello,
I'm working on a big project(big for me), where I've one main window that host 3 usercontrols using a library like avalondock to have an IDE-like apparance like visualstudio.
The app should work like this: the main window is loaded and ask with a openfiledialog to open a binary log file, then this log it's displayed in the 3 usercontrols in differtent way (pie chart,line chart and text), if the user change some value in the text view the other have to reflect it. Then if the user want, he can save the changed log with a savefiledialog.
So, I have more than 4k line of code for each usercontrol now; and things start to be a little messy..
So I'm planing to refactor it. For UI reasons I opted to wpf instead of winform; Now the thing that I would avoid is that:
I defined a shared array in the main window, and then to manipulate it from the usercontrol (placed into the mainwindow), I have to refer it as instance, that is not very readable.
I searched and tryed to implement MVVM pattern using a framwork (test done with caliburnmicro and stylet), but I'm struggling to understand how to share data between VMs. Considering that, test after test I had already rewrite the all project 6 time, I'm looking for some advice to made the code more readable and how structure the app, like use or not user design pattterns like mvvm, etc..
So anyone have any advice?

Answer 1

Hi Ajeje,
try following demo with 2 UserControls and 3 ViewModels; ViewModel0 - main ViewModel, ViewModel1 - for UserControl1, ViewModel2 - for UserControl2.

XAML Main Window:

<UserControl x:Class="Window096UC2"  
             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:WpfControlLibrary1.WpfApp096"  
             mc:Ignorable="d"   
             d:DesignHeight="450" d:DesignWidth="800">  
  <UserControl.Resources>  
    <local:ViewModel2 x:Key="vm2"/>  
  </UserControl.Resources>  
  <Border BorderBrush="Green" BorderThickness="2">  
    <StackPanel>  
      <Label Content="UserControl 2"/>  
      <TextBox Text="{Binding Text0, UpdateSourceTrigger=PropertyChanged}"  
               Margin="5"/>  
      <TextBox Text="{Binding Text2, Source={StaticResource vm2}, UpdateSourceTrigger=PropertyChanged}"  
               Margin="5"/>  
      <TextBox Text="{Binding Text2, Source={StaticResource vm2}, UpdateSourceTrigger=PropertyChanged}"  
               Margin="5"/>  
    </StackPanel>  
  </Border>  
</UserControl>  

XAML UserControl1:

<UserControl x:Class="Window096UC1"  
             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:WpfControlLibrary1.WpfApp096"  
             mc:Ignorable="d"   
             d:DesignHeight="450" d:DesignWidth="800">  
  <UserControl.Resources>  
    <local:ViewModel1 x:Key="vm1"/>  
  </UserControl.Resources>  
  <Border BorderBrush="Red" BorderThickness="2">  
    <StackPanel>  
      <Label Content="UserControl 1"/>  
      <TextBox Text="{Binding Text0, UpdateSourceTrigger=PropertyChanged}"  
               Margin="5"/>  
      <TextBox Text="{Binding Text1, Source={StaticResource vm1}, UpdateSourceTrigger=PropertyChanged}"  
               Margin="5"/>  
      <TextBox Text="{Binding Text1, Source={StaticResource vm1}, UpdateSourceTrigger=PropertyChanged}"  
               Margin="5"/>  
    </StackPanel>  
  </Border>  
</UserControl>  

XAML UserControl2:

<UserControl x:Class="Window096UC2"  
             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:WpfControlLibrary1.WpfApp096"  
             mc:Ignorable="d"   
             d:DesignHeight="450" d:DesignWidth="800">  
  <UserControl.Resources>  
    <local:ViewModel2 x:Key="vm2"/>  
  </UserControl.Resources>  
  <Border BorderBrush="Green" BorderThickness="2">  
    <StackPanel>  
      <Label Content="UserControl 2"/>  
      <TextBox Text="{Binding Text0, UpdateSourceTrigger=PropertyChanged}"  
               Margin="5"/>  
      <TextBox Text="{Binding Text2, Source={StaticResource vm2}, UpdateSourceTrigger=PropertyChanged}"  
               Margin="5"/>  
      <TextBox Text="{Binding Text2, Source={StaticResource vm2}, UpdateSourceTrigger=PropertyChanged}"  
               Margin="5"/>  
    </StackPanel>  
  </Border>  
</UserControl>  

ViewModels:

Imports System.ComponentModel  
Imports System.Runtime.CompilerServices  
  
Namespace WpfApp096  
  
  Public Class ViewModel0  
    Inherits ViewModelBase  
    Private _text0 As String  
    Public Property Text0 As String  
      Get  
        Return Me._text0  
      End Get  
      Set(value As String)  
        Me._text0 = value  
        OnPropertyChanged()  
      End Set  
    End Property  
  End Class  
  
  Public Class ViewModel1  
    Inherits ViewModelBase  
    Private _text1 As String  
    Public Property Text1 As String  
      Get  
        Return Me._text1  
      End Get  
      Set(value As String)  
        Me._text1 = value  
        OnPropertyChanged()  
      End Set  
    End Property  
  End Class  
  
  Public Class ViewModel2  
    Inherits ViewModelBase  
    Private _text2 As String  
    Public Property Text2 As String  
      Get  
        Return Me._text2  
      End Get  
      Set(value As String)  
        Me._text2 = value  
        OnPropertyChanged()  
      End Set  
    End Property  
  End Class  
  
  Public Class ViewModelBase  
      Implements INotifyPropertyChanged  
      Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged  
    Protected Sub OnPropertyChanged(<CallerMemberName> Optional propName As String = "")  
      RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(propName))  
    End Sub  
  End Class  
  
End Namespace  

Result: