switch between viewmodels on the same view using wpf mvvm

Question

I'm new to WPF MVVM, and a bit stuck. I need to switch between about 100 different tables on the same view using MVVM with wpf. I have Treeview with the list of table names and on item selection the correct DataGrid has to be displayed beside the Treeview. I created Model and ViewModel classes for each table. However, how do I select the right Viewmodel to bind depend on the selection.

Answer 1

If I understand your problem right - then you have a design problem.

First get the SelectedItem of your TreeView

To use the SelectedItem-Binding on a TreeView see this. But you could do also the bad way in the code behind.

Second bind your SelectedItem

So what you want to do is: bind the SelectedItem on something like a ContentControl or ContentPresenter. Or do it the bad way in the code behind.

For example like this:

<Grid>

<Grid.ColumnDefinitions>
    <ColumnDefinition />
    <ColumnDefinition />
</Grid.ColumnDefinitions>


<TreeView ItemsSource="{Binding MyItemSource}">
    <!-- Get the selected item here (watch how to in the linked answer) -->
</TreeView>


<ContentPresenter Grid.Column="1" 
                  Content="{Binding Path=SelectedItem}"
                  >
    <ContentPresenter.ContentTemplate>
        <DataTemplate>
            <DataGrid>
                <!-- Your DatGrids or what ever -->
            </DataGrid>
        </DataTemplate>
    </ContentPresenter.ContentTemplate>
</ContentPresenter>

</Grid>

Third (optional) If you have different DataGrids

You could also use a DataTemplateSelector to change your Views depending on your SelectedItem too. You would use it on the ContentPresenter in this example.