I have the following which works really well. (While it is somewhat against the principles of MVVM ... I still like to dynamically handle my user controls in a single frame area of the main window)
My MainWindow.xaml:
<!-- Main Frame -->
<Grid Grid.Column="1" Margin="10" Name="MainWindowFrameContent">
<ItemsControl ItemsSource="{Binding Path=MainWindowFrameContent}" >
<!-- This controls the height automatically of the user control -->
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<UniformGrid Columns="1" IsItemsHost="True"/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
</ItemsControl>
</Grid>
My MainViewModel.cs:
using System;
using System.Collections.ObjectModel;
using System.Windows;
using System.Windows.Input;
using myProject.View;
using myProject.Models;
namespace myProject.ViewModel
{
public class MainViewModel : ObservableObject
{
public MainViewModel() { }
// This handles adding framework (UI) elements to the main window frame
ObservableCollection<FrameworkElement> _MainWindowFrameContent = new ObservableCollection<FrameworkElement>();
public ObservableCollection<FrameworkElement> MainWindowFrameContent
{
get { return _MainWindowFrameContent; }
set { _MainWindowFrameContent = value; RaisePropertyChangedEvent("MainWindowFrameContent"); }
}
}
}
MainViewModel.cs is a "public class MainViewModel : ObservableObject". This allows me to implement "RaisePropertyChangedEvent" so that the binding will successfully update when I change the value of "MainWindowFrameContent".
My ObservableObject.cs:
using System.ComponentModel;
namespace myProject.ViewModel
{
public class ObservableObject : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected void RaisePropertyChangedEvent(string propertyName)
{
var handler = PropertyChanged;
if (handler != null)
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}
Then when I want to add an item to the MainWindowFrameContent, I simply do the following within my MainViewModel.cs:
void _AddNewUserControl()
{
myUserControl hControl = new myUserControl();
MainWindowFrameContent.Clear(); // Clear the frame before displaying new content
MainWindowFrameContent.Add(hControl);
}
Then you can create as many user controls as you would like. Each command you want to display can have its own void _AddNewUserControl type method in the VM and it will display to the main window. Again, its a bit contrary to the MVVM framework, but it keeps this pretty clean from a code base.
