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Visual Studio Intellisense doesn't suggest source-generated properties when binding in WPF

I'm not getting intellisense suggestions for properties that were source generated by the MVVM community toolkit. Is there a way to fix this? If I can't get the suggestions to work, then using [ObservableProperty] isn't even worth it IMO. Example below.
ViewModel has one source generated property and one handmade property:
public partial class SimplisticViewModel : ObservableObject
{
[ObservableProperty]
private int sourceGeneratedProperty;
private float handmadeProperty;
public float HandmadeProperty
{
get => handmadeProperty;
set => SetProperty(ref handmadeProperty, value);
}
}
XAML:
<Window x:Class="WPFEFTest.TestWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:WPFEFTest"
mc:Ignorable="d"
Title="TestWindow" Height="450" Width="800">
<Window.DataContext>
<local:SimplisticViewModel/>
</Window.DataContext>
<StackPanel>
<TextBox Text=""/>
</StackPanel>
</Window>
When setting up binding for the handmade property, the suggestions work:
When setting up binding for the source generated property, there are no suggestions:
However, if I write the entire property name (avoiding typos and such...) and hover my cursor over it (cursor not visible in screenshot), intellisense will correctly show the type of the property. So the problem probably isn't that intellisense doesn't "see" the property at all.
EDIT: To make it clear I'm not trying to bind to a field, below is code that MVVM community toolkit generates because of the ObservableProperty attribute:
public partial class SimplisticViewModel
{
[global::System.CodeDom.Compiler.GeneratedCode("Microsoft.Toolkit.Mvvm.SourceGenerators.ObservablePropertyGenerator", "7.1.0.0")]
[global::System.Diagnostics.DebuggerNonUserCode]
[global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
public int SourceGeneratedProperty
{
get => sourceGeneratedProperty;
set
{
if (!global::System.Collections.Generic.EqualityComparer<int>.Default.Equals(sourceGeneratedProperty, value))
{
OnPropertyChanging(global::Microsoft.Toolkit.Mvvm.ComponentModel.__Internals.__KnownINotifyPropertyChangedOrChangingArgs.SourceGeneratedPropertyPropertyChangingEventArgs);
sourceGeneratedProperty = value;
OnPropertyChanged(global::Microsoft.Toolkit.Mvvm.ComponentModel.__Internals.__KnownINotifyPropertyChangedOrChangingArgs.SourceGeneratedPropertyPropertyChangedEventArgs);
}
}
}
}

Maybe you could try setting DataContext for window... Same thing/issue you describe happens when I remove d:DataContext which points to ViewModel class and when DataContext is set, Intellisense picks up properties from ViewModel.
<Window x:Class="WPFEFTest.TestWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:WPFEFTest"
xmlns:viewmodels="clr-namespace:WPFEFTest.ViewModels"
mc:Ignorable="d"
Title="TestWindow" Height="450" Width="800" d:DataContext="{d:DesignInstance Type=viewmodels:SimplisticViewModel>

UWP inherit from a class inherited from UserControl

I am porting a Silverlight application to UWP Windows 10 app.
Large part of it has controls, inherited from a class, which inherits from UserControl.
base:
public abstract class PartBase : UserControl, IPart, IDisposable
concrete:
public sealed partial class MyPart : PartBase
its XAML:
<local:PartBase
I get compilation error : The name "PartBase" does not exist in the namespace ..
Is inheritance permitted in UWP ?

Your code should work. I've created your abstract base class and a new control based on that class.
<local:PartBase
x:Class="UWPTest.Controls.MyUserControl1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:UWPTest.Controls"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
d:DesignHeight="300"
d:DesignWidth="400">
<Grid>
<Button>Test</Button>
</Grid>
</local:PartBase>
Double check that the xmlns:local="using:UWPTest.Controls" is correct with the namespace PartBase is declared in. Then rebuild your solution and the error should go away (you will see the error if you don't rebuild).
On a page (e.g. MainPage) I can simply use the control:
<Page
x:Class="UWPTest.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:controls="using:UWPTest.Controls"
mc:Ignorable="d">
<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<controls:MyUserControl1 />
</Grid>
</Page>
Note the xmlns:controls pointing to the correct namespace. The designer will also give an error until you rebuild the app.
Everything builds here and the application runs, so if you still have the error after double checking all namepace declarations you'll have to put a repro online so we can check what else goes wrong.

How to implement converter class in usercontrol

I want to make a converter class , I implemented it and i want to use it in another xaml class
So i write this code
<UserControl
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:PoliceApp"
xmlns:common="using:PoliceApp.Common"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">
<UserControl.Resources>
<local:TitleToImgConverter x:Key="BoolOrConverter"/>
</UserControl.Resources>
</UserControl>
It tells me that there is a missing attribute for user control
and my first code was
DataContext="{Binding DefaultViewModel, RelativeSource={RelativeSource Self}}"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:PoliceApp"
xmlns:common="using:PoliceApp.Common"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">
<UserControl.Resources>
<local:TitleToImgConverter x:Key="BoolOrConverter"/>
</UserControl.Resources>
And the error was "The name titletoimgconverter doesnt exist in the namespace using:policeApp"

This is normal (at least, I have never seen it otherwise) when you have just created a new converter and added it as a resource in your XAML code. XAML code often lags behind when something is added to the namespace.
The solution for this is to rebuild your entire project. The XAML should now be able to locate your converter, and the error should disappear.
Update
If your converter exists in some folder called Converter, you should use your first example, and replace xmlns:local="using:PoliceApp" with xmlns:local="clr-namespace:PoliceApp.Converter". If it just resides in your main folder, you can leave out the .Converter. Note that I've replaced the using: with clr-namespace:.

Adding UserControl from one window to the MainWindow

I have a Mainwindow and a groupbox inside it.
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
x:Class="WpfApplication1.MainWindow"
Title="MainWindow"
Height="600" Width="800">
<Grid x:Name="MainGrid">
<GroupBox Header="Diagram Design" Name="gbDiagDesign">
</GroupBox>
</Grid>
</Window>
A simple UserControl
<UserControl x:Class="WpfApplication1.Controls.EntityControl"
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"
mc:Ignorable="d"
d:DesignHeight="100" d:DesignWidth="100">
<Grid>
<Button x:Name="btn_show" Content="show me" />
</Grid>
</UserControl>
and another window with an OK button in it,
the question is how do I add the UserControl to the Groupbox in the MainWindow after I press the OK button.
public partial class NewEntity
{
public NewEntity()
{
InitializeComponent();
}
private void OK_Click(object sender, RoutedEventArgs e)
{
EntityControl entcon = new EntityControl();
**MainWindow.gbDiagDesign.Children.Add(**
}
the last row gives me an error, "an object reference is required for the nonstatic field.."

You can access MainWindow using Application.Current.MainWindow but it will return instance of Window class. Typecasting is required to convert it to actual class instance i.e. MainWindow.
This should work:
((MainWindow)Application.Current.MainWindow).gbDiagDesign.Add(entcon);

WPF is meant to be programmed using the MVVM pattern. If you do it another way, you will have to fight WPF all along instead of using it's great power. If you insist on doing it the other way, at least make the compiler happy:
MainWindow is a instance variable of your application class. You are not inside your application class, so you need an instance of your application class first to access MainWindow. You will also need to cast it to your Window type.

Adding .cs in a ResourceDictionary?

I have DataTemplate in a ressource dictionnary, and in some, I need button and i don't know how i can use code behind for manage events.
I tried to put a class in my resource dictionnary like that :
<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
x:Class="SLProject.Templates"
x:Class="TVTemplate">
And I definied the class in the cs file like that :
namespace SLProject.Templates
{
partial class TVTemplate
{
}
}
The build is OK but when the application started, I obtains XAML error following :
AG_E_PARSER_BAD_TYPE
I tried all I know like change the class kind to a ClassModifier, make the class to an inherited class of RessourceDictionnary ... no way.
Someone have an idee ...
Thanks.

Using the x:Class attribute allows you to define a codebehind for a ResourceDictionary.
You must specify the complete namespace of the class (i.e. x:Class="WpfApplication.MyClass"), and such class has to be defined as partial (at least VS 2010 complains and does not compile without such modifier).
I mocked-up a simple example:
1. Create a new WPF application project (WpfApplication)
2. Add a new class file (TestClass.cs) and paste the following code
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Input;
using System.Windows;
namespace WpfApplication
{
public partial class TestClass
{
private void OnDoubleClick(object obj, MouseButtonEventArgs args)
{
MessageBox.Show("Double clicked!");
}
}
}
3. Add a new ResourceDictionary (Resources.xaml), open the file and paste the following code
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
x:Class="WpfApplication.TestClass">
<Style TargetType="{x:Type Label}">
<EventSetter Event="Label.MouseDoubleClick" Handler="OnDoubleClick"/>
</Style>
</ResourceDictionary>
4. Finally, open the MainWindow.xaml and past the following code
<Window x:Class="WpfApplication.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Window.Resources>
<ResourceDictionary Source="Resources.xaml"/>
</Window.Resources>
<Grid>
<Label Content="Double click here..." HorizontalContentAlignment="Center" VerticalContentAlignment="Center" Background="Red"/>
</Grid>
</Window>
In the example I wire-up a double-click event from a Style, since it is a scenario requiring you to call some code from a ResourceDictionary.

You have the x:Class attribute defined twice, which is why you're getting the parser error. Change your declaration to this and it should work:
<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
x:Class="SLProject.Templates.TVTemplate">

I Checked, and it's just an error of copy-past. I have well the class definied one time.

Best thing would be to make your own usercontrol and add your events in it . and later put this entire usercontrol in resource dictionary.