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Is there a way to pass an object parameter as a reference to a WPF Usercontrol

I am struggling to get a user control to accept a property from my Data Context object. I don't want to pass just the value; but the instance of the property because I would like to have converters operate on the attributes of the property.
I am very new to the WPF space, I've read many articles and none of them don't address this issue. The reason I'm trying to do this is because I have a calculations class that has many properties that need to be displayed and I don't really want to create a user control for each property or have 2,000 lines of repetitious XAML.
Any insight would be greatly appreciated.
Example Class
public class MyClass
{
[MyAttribute("someValue")]
public string Foo { get; set; }
}
View Model
public class MyViewModel : INotifyPropertyChanged
{
private _myClass;
public MyClass MyClass1
{
get => _myClass;
set
{
if(_myClass != value)
{
_myClass = value;
OnPropertyChanged();
}
}
}
}
Parent XAML
<UserControl DataContext="MyViewModel">
<Grid>
<!-- this is where I'm struggling, I think -->
<uc:MyConsumerControl ObjectProp="{Binding Path=MyClass1.Foo}"/>
</Grid>
</UserControl>
User Control
XAML
<UserControl DataContext={Binding RelativeSource={RelativeSource Mode=Self}}>
<Grid>
<TextBox Text="{Binding ObjectProp}"/>
<TextBlock Text="{Binding Path=ObjectProp, Converter={StaticResource MyAttrConverter}}"/>
</Grid>
</UserControl>
C#
public class MyConsumer : UserControl
{
public MyConsumer { InitializeComponent(); }
public object ObjectProp
{
get => (object)GetValue(ObjDepProp);
set => SetValue(ObjDepProp, value);
}
public static readonly DependencyProperty ObjDepProp =
DependencyProperty.Register(nameof(ObjectProp),
typeof(object), typeof(MyConsumer));
}

First of all, there is a naming convention for identifier fields of dependency properties:
public static readonly DependencyProperty ObjectPropProperty =
DependencyProperty.Register(nameof(ObjectProp), typeof(object), typeof(MyConsumer));
public object ObjectProp
{
get => GetValue(ObjectPropProperty);
set => SetValue(ObjectPropProperty, value);
}
Second, a UserControl that exposes bindable properties must never set its own DataContext, so this is wrong:
<UserControl DataContext={Binding RelativeSource={RelativeSource Mode=Self}}>
The XAML should look like this:
<UserControl ...>
<Grid>
<TextBox Text="{Binding ObjectProp,
RelativeSource={RelativeSource AncestorType=UserControl}}" />
<TextBlock Text="{Binding Path=ObjectProp,
RelativeSource={RelativeSource AncestorType=UserControl}, />
Converter={StaticResource MyAttrConverter}}"
</Grid>
</UserControl>
Finally, this is also wrong, because it only assigns a string to the DataContext:
<UserControl DataContext="MyViewModel">
It could probably look like shown below - although that would again explicitly set the DataContext of a UserControl, but perhaps one that could be considered a top-level view element like a Window or Page.
<UserControl ...>
<UserControl.DataContext>
<local:MyViewModel/>
</UserControl.DataContext>
<Grid>
<uc:MyConsumerControl ObjectProp={Binding Path=MyClass1.Foo}
</Grid>
</UserControl>

Prism Parent TabControl Child Regions

Trying to create a TabControl Region inside another Region. The TabControl has a set number of Views that will be added to it, with their own respective ViewModels.
But either the View doesn't show up, the tabitem doesn't show up with only one View displayed instead, or I get the following error:
System.ArgumentException: 'This RegionManager does not contain a Region with the name 'ParentTabRegion'. (Parameter 'regionName')'
MainMenuView:
<Grid>
<ContentControl prism:RegionManager.RegionName="ContentRegion" />
</Grid>
MainMenuViewModel:
public class MainMenuViewModel : BindableBase
{
private readonly IRegionManager _regionManger;
public MainMenuViewModel(IRegionManager regionManager)
{
_regionManger = regionManager;
_regionManger.RequestNavigate("ContentRegion", "ParentView");
}
}
ParentView:
<Grid>
<TabControl prism:RegionManager.RegionName="ParentTabRegion" />
</Grid>
ParentViewModel:
public class ParentViewModel : BindableBase
{
private readonly IRegionManager _regionManger;
private Child1View _tab1 = new Child1View();
private Child1View Tab1
{
get { return _tab1; }
set { SetProperty(ref _tab1, value); }
}
private Child2View _tab2 = new Child2View();
private Child2View Tab2
{
get { return _tab2; }
set { SetProperty(ref _tab2, value); }
}
public ParentViewModel(IRegionManager regionManger)
{
_regionManger = regionManger;
// Gives 'This RegionManager does not contain a Region with the name 'GeneralDataTabRegion'. (Parameter 'regionName')' error
_regionManger.AddToRegion("ParentTabRegion", typeof(Child1View));
_regionManger.AddToRegion("ParentTabRegion", typeof(Child2View));
//I've also tried the following
// Same error as above
// _regionManger.Regions["ParentTabRegion"].Add(typeof(Tab1View));
// _regionManger.Regions["ParentTabRegion"].Add(typeof(Tab2View));
// Same error as above
// _regionManger.AddToRegion("ParentTabRegion", Tab1);
// _regionManger.AddToRegion("ParentTabRegion", Tab2);
// Only the last registered view is displayed
// _regionManger.RegisterViewWithRegion("ParentTabRegion", typeof(Tab1));
// _regionManger.RegisterViewWithRegion("ParentTabRegion", typeof(Tab2));
}
}
I also have the prism namespace in all the views:
xmlns:prism="http://prismlibrary.com/"
prism:ViewModelLocator.AutoWireViewModel="True"
Maybe I'm not registering the ParentTabRegion somehow? But I don't have to register the other regions and they seem to just work out of the box.
Let me know if you know what I'm doing wrong or if there is something I'm missing. Thank you.

I would just comment but can't due to low reputation. Anyway..
Check this post
Prism 7 throws and exception when working with nested views
As stated in the comments: "the problem is about how to inject scope region in ViewModel"
This video from Brian should help you with the issue.
https://app.pluralsight.com/library/courses/prism-mastering-tabcontrol

I tested some other things out. Since I don't need dynamic tabs, I found this to be the cleanest solution using Prism:
Parent ViewModel:
public ParentViewModel(IRegionManager regionManager)
{
_regionManager = regionManager;
_regionManager.RegisterViewWithRegion("ChildRegion", typeof(Child1View));
_regionManager.RegisterViewWithRegion("ChildRegion", typeof(Child2View));
}
Parent View:
<UserControl.Resources>
<Style TargetType="TabItem">
<Setter Property="Header"
Value="{Binding DataContext.Title}"/>
</Style>
</UserControl.Resources>
<Grid>
<TabControl prism:RegionManager.RegionName="ChildRegion" />
</Grid>

I ended up doing this a bit differently since I don't really need to dynamically add Tabs.
So what I ended up doing was just adding all the ViewModels to an ObservableCollection of BindableBase. Then I just added them to the view using a DataTemplate.
Parent ViewModel:
private ObservableCollection <BindableBase> _childTabs;
public ObservableCollection <BindableBase> ChildTabs
{
get { return _childTabs; }
set { _childTabs = value; }
}
public ParentViewModel()
{
ChildTabs = new ObservableCollection <BindableBase> {
new Child1ViewModel(),
new Child2ViewModel()
};
}
Parent View:
<TabControl ItemsSource="{Binding ChildTabs}"
SelectedIndex="0">
<TabControl.Resources>
<DataTemplate DataType="{x:Type vm:Child1ViewModel}">
<view:Child1 />
</DataTemplate>
<DataTemplate DataType="{x:Type vm:Child2ViewModel}">
<view:Child2 />
</DataTemplate>
</DataTemplate>
</TabControl.Resources>
<TabControl.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Title}" />
</DataTemplate>
</TabControl.ItemTemplate>
</TabControl>
I still feel like I'm doing something wrong though, this doesn't feel like MVVM to me...

Creating generalized user controls with MVVM Light

How to create a general user control using MVVM Light?
All the main views in the application seem to work fine. However, general controls doesn't seem to accept bindings. This is my FileDiplay control. An icon and a TextBlock displaying a filename next to it.
Utilization
In one of the main views, I try to bind a FileName inside an ItemsTemplate of an ItemsControl. Specifying a literal, like FileName="xxx" works fine, but binding doesn't.
<local:FileLink FileName="{Binding FileName}" />
I've been playing around with DependencyProperty and INotifyPropertyChanged a lot. And seemingly there's no way around a DependencyProperty, since it can't be bound otherwise. When using a simple TextBlock instead of this user control, binding is accepted.
I didn't include the locator or the utilizing control in order to avoid too much code. In fact, I think this is a very simple problem that I haven't found the solution for, yet. I do think that having the DataContext set to the ViewModel is correct, since no list binding or real UserControl separation is possible. I've also debugged into the setters and tried the different approaches.
FileLink.xaml
<local:UserControlBase
x:Class="....FileLink"
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:..."
mc:Ignorable="d" DataContext="{Binding FileLink, Source={StaticResource Locator}}">
<Grid>
<StackPanel Orientation="Horizontal">
<Image Source="{Binding Icon}" Margin="0,0,5,0" />
<TextBlock Text="{Binding FileName}" />
</StackPanel>
</Grid>
</local:UserControlBase>
FileLink.xaml.cs
using System.Windows;
using System.Windows.Media;
namespace ...
{
public partial class FileLink : UserControlBase
{
private FileLinkViewModel ViewModel => DataContext as FileLinkViewModel;
public static DependencyProperty FileNameProperty = DependencyProperty.Register(nameof(FileName), typeof(string), typeof(FileLink));
public ImageSource Icon
{
get
{
return App.GetResource("IconFileTypeCsv.png"); // TODO:...
}
}
public string FileName
{
get
{
return ViewModel.FileName;
}
set
{
ViewModel.FileName = value;
}
}
public FileLink()
{
InitializeComponent();
}
}
}
FileLinkViewModel.cs
using GalaSoft.MvvmLight;
namespace ...
{
public class FileLinkViewModel : ViewModelBase
{
private string _FileName;
public string FileName
{
get
{
return _FileName;
}
set
{
Set(() => FileName, ref _FileName, value);
}
}
}
}

Do not explicitly set the DataContext of your UserControl, because it effectively prevents that the control inherits the DataContext from its parent control, which is what you expect in a Binding like
<local:FileLink FileName="{Binding FileName}" />
Also, do not wrap the view model properties like you did with the FileName property. If the view model has a FileName property, the above binding works out of the box, without any wrapping of the view model.
If you really need a FileName property in the UserControl, it should be a regular dependency property
public partial class FileLink : UserControlBase
{
public FileLink()
{
InitializeComponent();
}
public static readonly DependencyProperty FileNameProperty =
DependencyProperty.Register(nameof(FileName), typeof(string), typeof(FileLink));
public string FileName
{
get { return (string)GetValue(FileNameProperty); }
set { SetValue(FileNameProperty, value); }
}
}
and you should bind to it by specifying the UserControl as RelativeSource:
<local:UserControlBase ...> <!-- no DataContext assignment -->
<StackPanel Orientation="Horizontal">
<Image Source="IconFileTypeCsv.png" Margin="0,0,5,0" />
<TextBlock Text="{Binding FileName,
RelativeSource={RelativeSource AncestorType=UserControl}}" />
</StackPanel>
</local:UserControlBase>

Inject view into TabControl using prism library

That's how I defined TabControl:
<TabControl ItemsSource="{Binding OpenedProjects, UpdateSourceTrigger=PropertyChanged}"
SelectedItem="{Binding SelectedProject, Mode=OneWay}">
<!-- headers -->
<!-- header definition is unimportant for this question -->
<!-- content -->
<TabControl.ContentTemplate>
<DataTemplate>
<local:ProjectView />
</DataTemplate>
</TabControl.ContentTemplate>
</TabControl>
And these are the two methods I have defined in my Module class, that are used to register and use views:
protected override void _initializeViews() {
_container.RegisterType<MainMenuView>();
_container.RegisterType<ProjectsView>();
_container.RegisterType<ProjectView>();
_container.RegisterType<ContentView>();
}
protected override void _initializeRegions() {
IRegion menuRegion = _regionManager.Regions[RegionNames.MainMenuRegion];
IRegion projectsRegion = _regionManager.Regions[RegionNames.ProjectsRegion];
IRegion contentRegion = _regionManager.Regions[RegionNames.ContentRegion];
menuRegion.Add(_container.Resolve<MainMenuView>());
projectsRegion.Add(_container.Resolve<ProjectsView>());
contentRegion.Add(_container.Resolve<ContentView>());
}
And the View constructor:
public ProjectView(ProjectsViewModel vm) {
InitializeComponent();
DataContext = vm;
}
What I want to achieve is to inject ProjectView into TabControl's content area. Obviously, currently it doesn't work because of the ViewModel argument in the above constructor. How can I create this functionality, the PRISM way?
EDIT:
I found this: How to inject views into TabControl using Prism? however if I do the same as the author of that question, I'm getting:
System.InvalidOperationException: ItemsControl's ItemsSource property is not empty.

You TabControl didn't have a region so you can't inject something into your TabControl. Otherwise you only use simple MVVM to inject something into your view.
To use Prism to inject something in your TabControl. You only need this line:
<TabControl prism:RegionManager.RegionName="TabRegion"/>
And then you can inject something very easy into your View.
_regionManager.RequestNavigate("TabRegion", new Uri("ProjectView", UriKind.Relative));
Before that you have to add the View to your Containier with:
UnityContainer.RegisterType<object, ProjectView>("ProjectView");
To add the Headertext you can easy changed the Style of the TabItem and bind the Header to the ViewModel from the ProjectView:
<UserControl.Resources>
<Style TargetType="TabItem">
<Setter Property="Header" Value="{Binding DataContext.Name}" />
</Style>
</UserControl.Resources>
I hope that was the answer you looking for^^

The answer from #ascholz help me to implement this. Although the last step didn't work for me:
<UserControl.Resources>
<Style TargetType="TabItem">
<Setter Property="Header" Value="{Binding DataContext.Name}" />
</Style>
</UserControl.Resources>
What i did instead was:
1 - Create a Tab Control with a prism region (Inside MainWindows in my case).
<TabControl prism:RegionManager.RegionName="TabRegion"/>
2 - Create a "user control" of type TabItem (NewTabView) that holds the tab views. Note that i'm binding the Header here. The idea here would be to add a region here as well inside the grid (for the content of the tab), or to make every control that needs to be inside the tab a child of TabItem.
<TabItem
x:Class="Client.WPF.Views.NewTab"
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"
Header="{Binding Title}">
<Grid>
<Button Content="{Binding RandomNumber}"/>
</Grid>
</TabItem>
///The code behind should inherit from TabItem as well
public partial class NewTab : TabItem
///The viewmodel has a "Title" property
private string _title = "New Tab";
public string Title
{
get { return _title; }
set { SetProperty(ref _title, value); }
}
4 - Finally, i navigate to the NewTab like this (MainWindowViewModel code)
public DelegateCommand NewTab { get; }
public MainWindowViewModel(IRegionManager regionManager, IEventAggregator eventAggregato)
{
this.regionManager = regionManager;
this.eventAggregator = eventAggregator;
NewTab = new DelegateCommand(NewTabAction);
}
private void NewTabAction()
{
regionManager.RequestNavigate("TabRegion", "NewTab");
}
5 - As an added bonus, if you want to allow more than 1 instance of the tab, you can do something like this on the view model (NewTabViewModel).
///First add the IConfirmNavigationRequest interface
public class NewTabViewModel : BindableBase, IConfirmNavigationRequest
///...
///Then the implementation should look like this
public void ConfirmNavigationRequest(NavigationContext navigationContext, Action<bool> continuationCallback)
{
continuationCallback(true);///Will allow multiple instances (tabs) of this view
}
public void OnNavigatedTo(NavigationContext navigationContext)
{
}
public bool IsNavigationTarget(NavigationContext navigationContext)
{
return false;
}
public void OnNavigatedFrom(NavigationContext navigationContext)
{
}
Or you could also add views directly to the region. Although you would need to resolve views using the IContainerProvider. Something like this:
var view = containerProvider.Resolve<NewTab>();
regionManager.Regions["TabRegion"].Add(view);

Binding ViewModel to ContentControl as its DataContext

I want to change UserControls on button clicks (I'm not going to complicate here, so I'll only mention important parts). So idea was to bind ViewModels of those UserControls to ContentControl, and than associate them Views using DataTemplates.
Here's the code:
<Window x:Class="Project.MainWindow">
<Window.Resources>
<DataTemplate DataType="{x:Type UserControl:ViewUserControlViewModel}" >
<UserControl:ViewUserControl/>
</DataTemplate>
<DataTemplate DataType="{x:Type UserControl:EditUserControlViewModel}" >
<UserControl:EditUserControl/>
</DataTemplate>
</Window.Resources>
<Grid>
<ContentControl DataContext="{Binding UserControlViewModel}" />
<Button Content="View" Click="ChangeToView()"/>
<Button Content="Edit" Click="ChangeToEdit()"/>
</Grid>
</Window>
ViewModel:
public class MainWindowViewModel : DependencyObject
{
public DependencyObject UserControlViewModel
{
get { return (DependencyObject)GetValue(UserControlViewModelProperty); }
set { SetValue(UserControlViewModelProperty, value); }
}
public static readonly DependencyProperty UserControlViewModelProperty =
DependencyProperty.Register("UserControlViewModel", typeof(DependencyObject), typeof(MainWindowViewModel), new PropertyMetadata());
public MainWindowViewModel()
{
UserControlViewModel = new EditUserControlViewModel();
}
}
But theres a problem. When I start project, I only see buttons but not any UserControls. What did I do wrong?

If your Window.DataContext is properly set to MainWindowViewModel this should do the job
<ContentControl Content="{Binding UserControlViewModel}" />

When doing mvvm your viewmodel should implement INotifyPropertyChanged and not inherit from DependencyObject.
public class MainWindowViewModel : INotifyPropertyChanged
{
private object _currentWorkspace; //instead of object type you can use a base class or interface
public object CurrentWorkspace
{
get { return this._currentWorkspace; }
set { this._currentWorkspace = value; OnPropertyChanged("CurrentWorkspace"); }
}
public MainWindowViewModel()
{
CurrentWorkspace= new EditUserControlViewModel();
}
//todo: to switch the workspace, create DelegeCommand/RelayCommand and set the CurrentWorkspace
//if you don't know about these commands let me know and i post it
public ICommand SwitchToViewCommand {get{...}}
public ICommand SwitchToEditCommand {get{...}}
}
xaml: you should set the Content Property to your CurrentWorkspace.
<ContentPresenter Content="{Binding UserControlViewModel}" />
<Button Content="View" Comamnd="{Binding SwitchToViewCommand}"/>
<Button Content="Edit" Comamnd="{Binding SwitchToEditCommand}"/>
! Don't forget to set the DataContext for your window to your MainWindowViewModel instance.

First of all you should post the code of your UserControl since (in your code snippet above) it's responsible for displaying some data.
Second you are not binding anything in your code.
Third your implementation of the ViewModel is wrong. You don't need to subclass a DependencyObject but instead implement the INotifyPropertyChanged interface in order to establish a ViewModel that is capable of notifying your View.
Fourth I don't know what you are doing with
<ContentControl DataContext="{Binding UserControlViewModel}" />
maybe you can explain further ?
Fifth when implementing the MVVM patterm (what you currently not do) you should avoid using events like the click event and instead use Commands.
(I know that's not a real answer yet, but I don't wanted to write in comment syntax)