Working with local ViewModel in MVVM WPF application

Question

I am having trouble accessing my ViewModel when working with my view.

I have a project named BankManagerApplication. Within that I have the various files associated with a new WPF application. I have created three seperate folders Model, ViewModel and View.

At the moment there is a UserModel class in the Model folder with the following fields;

namespace BankManagerApplication.Model
{
    public class UserModel
    {
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public double AccountBallance { get; set; }
    }
}

a blank view in the View folder with just a grid inside;

<Window x:Class="BankManagerApplication.View.MainWindowView"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindowView" Height="300" Width="300">
    <Grid>
    </Grid>
</Window>

and also a blank ViewModel in the ViewModel folder;

namespace BankManagerApplication.ViewModel
{
    public class MainWindowViewModel
    {
    }
}

when i try to reference the ViewModel in my XAML like so;

<Window x:Class="BankManagerApplication.View.MainWindowView"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindowView" Height="300" Width="300"
        xmlns:viewmodel="clr-namespace:BankManagerApplication.ViewModel">
    <Grid>
        <viewmodel:MainWindowViewModel></viewmodel:MainWindowViewModel>
    </Grid>
</Window>

i get the error

The name 'MainWindowViewModel does not exist in the namespace "clr-namespace:BankManagerApplication.ViewModel'

I have only just started learning WPF and this error is throwing me off before I have really begun

Answer 1

You cannot add it to a Grid control because it is not a UIElement. Your viewmodel will be the DataContext of your view:

<Window x:Class="BankManagerApplication.View.MainWindowView"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindowView" Height="300" Width="300"
    xmlns:viewmodel="clr-namespace:BankManagerApplication.ViewModel">
    <Window.DataContext>
       <viewmodel:MainWindowViewModel></viewmodel:MainWindowViewModel>
    </Window.DataContext>
    <Grid>

    </Grid>