Button with MVVM model in WPF and C#

Question

I am trying to create a button in WPF with MVVM model using C# that takes a picture when pressed and saves it to the specified path. What I'm basically doing is creating a button that when pressed, it orders a camera to take a picture and receives the image back (through an api Rest), which is later saved as a.jpg image to a specified path (specified in code below). I have done this without the MVVM model and it works perfectly, but I need to do it using MVVM model and I seem to be doing something wrong, because it is not working.

Here is my code:

XAML code (View): `

<Window x:Class="WpfApp1.MainWindow"
        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:WpfApp1"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <StackPanel>
            <TextBlock x:Name="instrucciones" Text="Press button" FontSize="30" Margin="50" TextAlignment="Center"/>
            <Button Content="Tomar Foto" Command="{Binding TakePhotoCommand}" Margin="5 0 5 5"  Width="200" FontSize="25" Padding="15 3"/>
        </StackPanel>
    </Grid>
</Window>

`

C# Code (ViewModel): `

public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            TakePhotoCommand = new RelayCommand(TakePhoto);
        }


        public void TakePhoto()
        {
 
            var request =(HttpWebRequest)WebRequest.Create("http://myIp+port/TakePicture");
            request.Method = "GET";
            request.ContentType = "application/x-www-form-urlencoded";

            try
            {
                using (WebResponse response = request.GetResponse())
                {

                    using (Stream strReader = response.GetResponseStream())
                    {
                        StreamReader reader = new StreamReader(strReader);
                        Bitmap bitmap = new Bitmap(strReader);
                        bitmap.RotateFlip(RotateFlipType.Rotate90FlipNone);
                        bitmap.Save("C:\\path+name.jpg", ImageFormat.Jpeg);
                    }

                }
            }
            catch (WebException ex)
            {
                MessageBox.Show(ex.ToString());
            }
        }

        public ICommand TakePhotoCommand { get; set; }
    }

`

Already described in question

Answer 1

First you are not using a MVVM pattern, you use MainWindow code-behind directly.

In your code you have to set the DataContext to this in the class constructor.

public MainWindow()
{
    InitializeComponent();
    TakePhotoCommand = new RelayCommand(TakePhoto);
    DataContext = this;
}