mvvmlight | main purpose of the toolkit is to accelerate the creation | Form library

I am using the Microsoft.Toolkit.Mvvm nuget package for building out a WPF application on .NET Core 3.1.

I'm having an issue with binding the CommandParameter of a button within a DataGridTemplateColumn of a Datagrid.

I have a RelayCommand defined on my viewmodel, using IRelayCommand, and have a CanExecute method defined that takes a parameter. I then have the CommandParameter of the button binding bound to the data of the datagrid row.

During runtime, I am seeing the CanExecute method called for every row of my datagrid, however the parameter value is always null. If I have 5 items in my ObservableCollection, I see CanExecute called 5 times, 3 items... 3 times. In all cases the value is null.

Below is the code for my viewmodel that creates an ObservableCollection of TestModel types. A RelayCommand is created, and the criteria of the CanExecute is dumbed down to just comparing the name property of the databound model.

What I'd expect here is that for all rows except the row with name "Test2", the bound button would be enabled. The button in Test2's row would be disabled.

Here is my viewmodel, and related model class.

I have class

I'm looking for the right approach to declare design-time ViewModel for an Avalonia window.

Some samples suggest

I'm building a simple application using WPF and GalaSoft MvvmLight (5.4.1.1).
Everything works fine, I have a grid, and when a row is selected I enable/disable buttons that have actions assigned.

Sample button looks like that:

I am currently working with WPF to create a simple minigame which requires pressing keys. I have done something similar with mouse clicking, yet I am struggling with keys. I have searched for a quite some time and I have found out that the most common way to work with keys is to define each key to its own event. But thats not my case and I want it to be able to fire it everytime any key is pressed. I have found out that this is possible to be done with MVVMLight and EventToCommand, but for some uknown reason to me, the KeyDown event will not fire (neighter KeyUp), but PreviewMouseLeftButtonDown will do.

xaml file:

I'm trying to update my DataGrid (name: dgLicenseholder, bound to an ObservableCollection. I am using MVVMLight) when I add new rows to the database. Why isn't this working?

In my ViewModel, I have a public DelegateCommand RefreshCommand {get; private set; } and a method:

I'm writing an app in WPF, trying to use the MVVM-design pattern (which is new to me). I have a DataGrid bound to an ObservableCollection.

Delete the currently selected DataGrid-row using a 'Delete'-button. I've tried a plethora of forum-posts and videos to find a solution. The solution has probably stared me right in the face several times, but at this point I'm more confused than I was when I first started.

Any assistance would be appreciated.

ViewModel (updated with working code, thanks to EldHasp):

I'm new on WPF and I want to create a program using MVVM pattern (without using external library like MvvmLight). The application let the user to draw rectangles (and other shapes in future) inside canvas using mouse (similar to Windows Paint, just to be clear). The user could move/resize created rectangles using mouse interaction as well.

At this moment I implemented a basic version in which the user can add a rectangle (with random size/position) by clicking a button. This is the code of the MainWindow view which implement this behaviour:

I'm troubleshooting a laundry list of exceptions that have recently begun to occur- We have a "single-use" service which we wrapped a bulk service around. The bulk service sets up all the variables required for each iteration, etc... The other variables are non-Entity/non-EF related. Roughly speaking: