Problem Binding via command.Can you help - binding

Question

New to wpf and through a learning curve.
I have a userControl with a Toolbar Save Button and a TextBox.
What I am trying to achieve is as follows
When I press the save Button in the toolbar I should record in the textbox that I am about to save and that I have saved the customer (CustomerView UserControl)
I seem to have 2 problems
1) that the SaveCommand is not hooked I thought I had hooked it
2) is not writing the action to the textbox.
Could you tell me where I am going wrong?
Thanks a lot!!!
MainWindow.xaml
<Window x:Class="MyCompany.CustomerStore.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:view="clr-namespace:MyCompany.CustomerStore.Views"
Title="MainWindow" Height="350" Width="525">
<Grid>
<view:CustomerView></view:CustomerView>
</Grid>
CustomerView.xaml
<UserControl x:Class="MyCompany.CustomerStore.Views.CustomerView"
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="300" d:DesignWidth="300">
<Grid>
<DockPanel LastChildFill="True">
<ToolBar DockPanel.Dock="Top">
<Button Command="{Binding Path=SaveCommand}">Save</Button>
</ToolBar>
<TextBox Name="txtPrintAction" Text="{Binding CustomerLog, Mode=TwoWay}"></TextBox>
</DockPanel>
</Grid>
CustomerModel.cs
public class CustomerModel
{
public string FirstName { get; set; }
public string LastName { get; set; }
public string CustomerLog { get; set; }
}
CustomerViewModel.cs
public class CustomerViewModel:WorkspaceViewModel,ICustomerViewModel
{
readonly CustomerModel _customerModel;
RelayCommand _saveCommand;
public CustomerViewModel(CustomerModel customer)
{
_customerModel = customer;
}
public string FirstName
{
get { return _customerModel.FirstName; }
set
{
_customerModel.FirstName = value;
base.OnPropertyChanged("FirstName");
}
}
public string LastName
{
get { return _customerModel.LastName; }
set
{
_customerModel.LastName = value;
base.OnPropertyChanged("LastName");
}
}
public string CustomerLog
{
get { return _customerModel.CustomerLog; }
set
{
_customerModel.CustomerLog = value;
base.OnPropertyChanged("CustomerLog");
}
}
public ICommand SaveCommand
{
get
{
if (_saveCommand == null)
{
_saveCommand = new RelayCommand(param => Save(), param => CanSave);
}
return _saveCommand;
}
}
private void Save()
{
AppendToLog("I am about to save");
//Pretend we have saved the customer
AppendToLog("CustomerSaved");
}
internal void AppendToLog(string text)
{
_customerModel.CustomerLog += text + Environment.NewLine; ;
OnPropertyChanged("CustomerLog");
}
static bool CanSave
{
get
{
return true;
}
}

Answer 1

Where do you declare a relationship between the view
x:Class="MyCompany.CustomerStore.Views.CustomerView
and the model class CustomerViewModel?
I don't see that anywhere.
I think you need to set the DataContext of the View to the Model.