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.

It would help if we know what you code looks like. You could use the same ViewModel for one TreeView entry and one DataGrid e.g. — Mighty Badaboom
Hello Mighty, All I'm currently have my model and viewmodel classes with INotifyPropertyChanged. I'm trying to implement what Peter suggested, but still not much success. — Vadim

Peter Peter · Accepted Answer · 2017-03-08T14:58:56

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.

switch between viewmodels on the same view using wpf mvvm

1 Answers