如何在运行时创建新区域

Question

I am developing a feature that allows users to select some data sources. Each data source can have different criteria. For example, say the data source is describing house hold items, if the user selects bread, I would give them a combo box to select brand, another to select type ie white, whole grain etc, if they select paint, I would have combo boxes to select color and amount. In other words, each data source type has a dedicated view and view model. In my case there are 10 different types of data sources and I have created view models for each type of data source and a corresponding view.

In my example I have a DataGrid which contains multiple rows. Each row has a cell dedicated to a data source and a combo box to allow user to change data sources. When the data source is changed, a new view model corresponding to the selected type of data source is created. I am using the Unity container to create an instance of the view then setting the data context. The data source is defined in the data grid. Each row of the data grid is a view model IRowViewModel which contains a property called PrimaryRegionName. I generate a random 16 character string for each row to be used as the region name. I bind RegionManager.RegionName to my property. (see below)

xaml

<DataGridTemplateColumn Header="Primary" >
    <DataGridTemplateColumn.CellTemplate>
        <DataTemplate>
            <ContentControl Grid.Row="1" 
                            prism:RegionManager.RegionName="{Binding PrimaryRegionName}" />
        </DataTemplate>
    </DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>

I create my view and register it with the region using the code below

> register the view with the container as a type. This is the active instance for a view model for the region
> "region" here is the region name e.g "000011112222ffff"
container.RegisterType(viewType, region);
> Resolve an instance of the view 
view = _container.Resolve(viewType, region);
_regionManager.RegisterViewWithRegion(region, view.GetType());
_regionManager.Regions[region].Add(view);
(view as System.Windows.FrameworkElement).DataContext = viewModel;

What I'm guessing is that when the view is created, since the data context is set later, there will be no region registered with the region manager for each new row. What I'm looking to know is, how do I create regions with names that are defined at run time?

Answer 1

After posting this I realised that all I had to do was create a new Region, set the name and add it to my region manager

_container.RegisterType(viewType, region);
view = _container.Resolve(viewType, region);
(view as System.Windows.FrameworkElement).DataContext = viewModel;
IRegion r = new Region();
r.Name = region;
_regionManager.Regions.Add(r);
_regionManager.RegisterViewWithRegion(region, view.GetType());
_regionManager.Regions[region].Add(view);