I have a WPF Window, and in that window I have a grid.
I use M-V-VM model and I want to add a TextBox to the grid dynamically in code(in viewmodel)
How can I get access to the grid?
Use Supervising Controller pattern.
Reading:
Example implementation for CaliburnMicro MVVM framework is shown here (will work same for all other frameworks - or you can do it by hand if you are doing MVVM by yourself):
http://drc.ideablade.com/devforce-2012/bin/view/Documentation/cocktail-tutorial-talk-to-view
Example:
1) Define interface IView
in which ViewModel
(VM
) will talk to View
with the required method(s)
public interface IView
{
void AddTextBoxToGrid();
}
2) Inherit code behind View
from your IView
and implement IView.AddTextboxToGrid()
method
public partial class View: IView
{
public void AddTextBoxToGrid()
{
// implement here your custom view logic using standard code behind;
}
}
3) Add a property of type IView
to your VM
public class ViewModel
{
public IView View { get; set; }
}
4) Set View
property on VM
to an instance of View
as IView
e.g. in code behind:
DataContext.View = this as IView;
or in Caliburn you can use IScreen.OnViewAttached override method)
public partial class View: IView
{
public View()
{
// access you VM by the strategy of your framework or choice - this example is when you store your VM in View's DataContext
(DataContext as ViewModel).View = this as IView;
}
public void AddTextBoxToGrid()
{
// implement here your custom view logic using standard code behind;
}
}
5) In your VM
call IView.AddTextboxToGrid()
public class ViewModel
{
public IView View { get; set; }
public void AddTextBoxToGrid()
{
if (View == null) return;
View.AddTextBoxToGrid()
}
}