Open new Window in an MVVM WPF App

Question

I have a WPF MVVM app that using PRISM. I have a toolbar UserControl which is bind to the ViewModel so it can invoke the commands on the ViewModels as shown below:

 <ToolBar Height="auto">
        <Button Content="New"/>
        <Button Content="Edit" Command="{Binding Path=EditCommand}" CommandParameter="{Binding SelectedItem}"  />
        <Button Content="Refresh"/>
        <Button Content="Delete"/>
        <Button Content="Close"/>
    </ToolBar>

The EditCommand invoke the following method in the ViewModel:

 private void Edit(UserViewModel userViewModel)
        {
            // load the edit page 



        }

In the Edit method I need to replace the current window with the edit window. How can I do that? I do not want to create or use UI elements in the Edit method because it goes against the MVVM model architecture.

Since you are already using PRISM, are you familiar with Interaction Requests? In MVVM you raise the request whenever you want a new dialog(usercontrol,window) — Krishna
You can read more about InteractionRequests over here msdn.microsoft.com/en-us/library/… — Krishna

123 456 789 0 123 456 789 0 · Accepted Answer · 2014-07-14T14:29:06

Create a DataTemplate for the current window that you have and create triggers to change the Template of the window to the Edit template.

Sample trigger

<Style TargetType="Window">
  <Style.Triggers>
      <DataTrigger Binding="{Binding IsInEditMode}" Value="True">
       <Setter Property="Template" Value="{StaticResource EditModeTemplate}">
      </DataTrigger>
  </Style.Triggers>
</Style>

Sample data template, assuming you just want a TextBox

<DataTemplate x:Key="EditModeTemplate">
  <TextBox/>
</DataTemplate>

In your Edit method, you can just set the a boolean property to true or false whether to show an edit window or not.

public void Edit(UserViewModel viewModel)
{
  IsInEditMode = true;
}

Open new Window in an MVVM WPF App

1 Answers