Hello I have a application design problem and I home you can help me solve it.... This is my first application in silverlight and the first application using mvvm design pattern and I am not sure I am applying mvvm how I am supposed to..
The application is a dynamic application and at runtime I can add/remove usercontrols...
So I have a MainWindowView that has behind a MainWindowModel.
The MainWindowModel has a list of Workspaces witch are in fact WorkspaceModel classes...
I have multiple UserControls and everyone off them has his own view model witch inherits WorkspaceModel.
The Workspaces property is binded to a container in MainWindowView so adding to the Workspaces list a new UserControlModel will automatically add that control to the view. Now where is my problem... I want to make this dynamically added usercontrols to interact. Lets say one user control is a tree and one is a grid... I want a method to say that Itemsource property of Grid UserControl Model (WorkspaceModel) to be binded to SelectedNode.Nodes Property from the Tree Usercontrol Model (WorkspaceModel).
The MainWindowModel has a property name BindingEntries witch has a list of BindingEntry... BindingEntry stores the source property and the destination property of the binding like my workspacemodel_1.SelectedNode.Nodes -> workspacemodel_2.ItemSource...
Or as a variation the MainWindowView has a property ViewStateModel. This ViewStateModel class has dynamic created properties - "injected" with property type descriptors/reflections etc... So the user can define at run time the displayed usercontrols (by modifying the Workspaces list) and can define a view model (the ViewStameModel) and the binding is between workspacemodel properties and this ViewStateModel properties...
So I actually want to bind 2 view models one to another... How to do that? Create an observer pattern? Is the design until now totally wrong?
I hope it makes sense.....
I will try to add some sample code...the project is quite big I will try co put only the part I have mentioned in the problem desciption... I hope I will not miss any pice of code
First of all
public class MainWindowModel : ModelBase
{
private ObservableCollection<WorkspaceModel> _workspaces;
private ModelBase _userViewModel;
public MainWindowModel()
{
base.DisplayName = "MainWindowModel";
ShowTreeView(1);
ShowTreeView(2);
ShowGridView(3);
ShowGridView(4);
UserViewModel = new ViewModel(); //this is the ViewStateModel
}
void ShowTreeView(int id)
{
WorkspaceModel workspace = ControlFactory.CreateModel("TreeControlModel", id);
this.Workspaces.Add(workspace);
OnPropertyChanged("Workspaces");
SelectedWorkspace = workspace;
}
void ShowGridView(int id)
{
WorkspaceModel workspace = ControlFactory.CreateModel("GridControlModel", id);
this.Workspaces.Add(workspace);
OnPropertyChanged("Workspaces");
SelectedWorkspace = workspace;
}
public ObservableCollection<WorkspaceModel> Workspaces
{
get
{
if (_workspaces == null)
{
_workspaces = new ObservableCollection<WorkspaceModel>();
}
return _workspaces;
}
}
public ModelBase UserViewModel
{
get
{
return _userViewModel;
}
set
{
if (_userViewModel == value)
{
return;
}
_userViewModel = value;
OnPropertyChanged("UserViewModel");
}
}
}
snippets from MainappView
<DataTemplate x:Key="WorkspaceItemTemplate">
<Grid >
//workaround to use Type as in WPF
<Detail:DetailsViewSelector Content="{Binding}" TemplateType="{Binding}" >
<Detail:DetailsViewSelector.Resources>
<DataTemplate x:Key="TreeControlModel" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" >
<TreeControl:TreeControlView />
</DataTemplate>
<DataTemplate x:Key="GridControlModel" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" >
<GridControl:GridControlView />
</DataTemplate>
<DataTemplate x:Key="EmptyTemplate">
</DataTemplate>
</Detail:DetailsViewSelector.Resources>
</Detail:DetailsViewSelector>
</Grid>
</DataTemplate>
<DataTemplate x:Key="WorkspacesTemplate">
<ItemsControl IsTabStop="False" ItemsSource="{Binding}" ItemTemplate="{StaticResource WorkspaceItemTemplate}" Margin="6,2"/>
</DataTemplate>
</UserControl.Resources>
<toolkit:HeaderedContentControl Grid.Column="2" HorizontalAlignment="Stretch" Name="hccWorkspaces" VerticalAlignment="Top" Header="Workspaces" Content="{Binding Source={StaticResource vm}, Path=Workspaces}" ContentTemplate="{StaticResource WorkspacesTemplate}"/>
public class ControlFactory
{
public static WorkspaceModel CreateModel(string type, int id)
{
switch (type)
{
case "TreeControlModel": return new TreeControlModel() { Id=id}; break;
case "GridControlModel": return new GridControlModel() { Id = id }; break;
}
return null;
}
}
public class GridControlModel : WorkspaceModel
{
#region Fields
ObservableCollection<TreeItem> _items;
TreeItem _selectedItem;
#endregion // Fields
#region Constructor
public GridControlModel()
{
base.DisplayName = "GridControlModel";
}
#endregion // Constructor
#region Public Interface
public ObservableCollection<TreeItem> Items
{
get
{
return _items;
}
set
{
if (_items == value)
return;
_items = value;
OnPropertyChanged("Items");
}
}
public TreeItem SelectedItem
{
get
{
return _selectedItem;
}
set
{
if (_selectedItem.Equals(value))
{
return;
}
_selectedItem = value;
OnPropertyChanged("SelectedItem");
}
}
#endregion // Public Interface
#region Base Class Overrides
protected override void OnDispose()
{
this.OnDispose();
}
#endregion // Base Class Overrides
}
<Grid x:Name="LayoutRoot" Background="White">
<sdk:DataGrid Grid.Column="2" Grid.Row="1" HorizontalAlignment="Stretch" Name="dataGrid1" VerticalAlignment="Stretch" ItemsSource="{Binding Path=SelectedTreeNode.Children}" IsEnabled="{Binding}" AutoGenerateColumns="False">
<sdk:DataGrid.Columns>
<sdk:DataGridTextColumn CanUserReorder="True" CanUserResize="True" CanUserSort="True" Header="Id" Width="Auto" Binding="{Binding Id}" />
<sdk:DataGridTextColumn CanUserReorder="True" CanUserResize="True" CanUserSort="True" Header="Name" Width="Auto" Binding="{Binding Name}"/>
</sdk:DataGrid.Columns>
</sdk:DataGrid>
</Grid>
</UserControl>