請問如何是否能解決這個程式要多個View去共享一個ViewModel的辦法？
目前這個程式的View架構如下：
MainWindow.xaml (window)
|__ReviewView.xaml (page)
　　|__DisplayControlView.xaml (page)
　　|__DisplayPanelView.xaml (page)
　　　　|__DisplayView.xaml (page)

ReviewView.xaml用frame容器包含DisplayControlView.xaml跟DisplayPanelView.xaml兩個Page
DisplayPanelView.xaml又往下包含了一個DisplayView.xaml
主要功能是-在DisplayControlView上有按鈕可以開啟圖檔，然後顯示在DisplayView上

目前找過文章說可以View設定DataContext綁定ViewModel，或是反過來，但是都沒很完整的範例示範，還請各位大大能幫幫忙！謝謝！

我試過用Singleton修改過，結果越改越糟糕........囧

以下是我原始的程式片段：
--DisplayControlView.xaml

<Page.DataContext>
    <vm:DisplayViewModel/>
</Page.DataContext>
...
<Button x:Name="btnDpOpen" Style="{DynamicResource ButtonStyle}" Width="120" Command="{Binding OpenFile}">
...

--DisplayView.xaml

<Page.DataContext>
    <vm:DisplayViewModel/>
</Page.DataContext>
...
<Image x:Name="imgDisplayView" Source="{Binding ImagePath}">
	<Image.RenderTransform>
		<TransformGroup>
			<TranslateTransform/>
			<RotateTransform/>
			<ScaleTransform/>
		</TransformGroup>
	</Image.RenderTransform>
</Image>
...

--DisplayViewModel.cs

class DisplayViewModel : ViewModelBase
{
	private DisplayImageModel image { get; set; }

	private ObservableCollection<DisplayImageModel> imagelist = new ObservableCollection<DisplayImageModel>();
	public ObservableCollection<DisplayImageModel> ImageList
	{
		get { return imagelist; }
		set
		{
			imagelist = value;
			OnPropertyChanged();
		}
	}

	public string ImagePath
	{
		get { return image.Path; }
		set
		{
			if (image.Path != value)
			{
				image.Path = value;
				OnPropertyChanged();
			}
		}
	}

	public DisplayViewModel()
	{
		image = new DisplayImageModel();
		ImagePath = @"C:\lenna.png";
	}

	public bool CanExecute()
	{
		return true;
	}

	public RelayCommand OpenFile
	{
		get { return new RelayCommand(openFile, CanExecute); }
	}

	private void openFile()
	{
		string[] picExtName = new string[] { ".PNG", ".JPG", "JEPG", "BMP" };

		OpenFileDialog dlgOpenFile = new OpenFileDialog() 
		{ Filter = "Picture|*.jpg;*.jpeg;*.bmp;*.png|All File|*.*" };
		if (dlgOpenFile.ShowDialog() != true)
		{
			return;
		}
		if (picExtName.Any(System.IO.Path.GetExtension(dlgOpenFile.FileName).ToUpper().Contains))
		{
			ImagePath = dlgOpenFile.FileName;
			OnPropertyChanged();

		}
	}
}

--ViewModelBase.cs

public abstract class ViewModelBase : INotifyPropertyChanged
{
	public event PropertyChangedEventHandler PropertyChanged;

	public void SetValue<T>(ref T property, T value, [CallerMemberName] string propertyName = null)
	{
		if (property != null)
		{
			if (property.Equals(value))
			{
				return;
			}
		}

		property = value;
		OnPropertyChanged(propertyName);
	}

	protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
	{
		if (PropertyChanged != null)
		{
			PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
		}
	}
}

--RelayCommond.cs

public class RelayCommand : ICommand
{
	readonly Func<bool> _canExecute;
	readonly Action _execute;

	public RelayCommand(Action execute) : this(execute, null)
	{
	}

	public RelayCommand(Action execute, Func<bool> canExecute)
	{
		_execute = execute ?? throw new ArgumentNullException("execute");
		_canExecute = canExecute;
	}
	
	public event EventHandler CanExecuteChanged
	{
		add
		{
			if (_canExecute != null) CommandManager.RequerySuggested += value;
		}
		remove
		{
			if (_canExecute != null) CommandManager.RequerySuggested += value;
		}
	}

	[DebuggerStepThrough]
	public bool CanExecute(object parameter)
	{
		return _canExecute == null ? true : _canExecute();
	}

	public void Execute(object parameter)
	{
		_execute();
	}
}