I try to rewrite my Application using the MVVM pattern.
I have a window to show related documents for different objects with static methods like this:
public partial class ShowRelatedDocuments : Window
{
private ShowRelatedDocuments()
{
InitializeComponent();
}
public static void ShowRelatedDocument(A objA)
{
ShowRelatedDocuments srd = new ShowRelatedDocuments();
srd.HandleA(objA);
srd.ShowDialog();
}
public static void ShowRelatedDocument(B objB)
{
ShowRelatedDocuments srd = new ShowRelatedDocuments();
srd.HandleB(objB);
srd.ShowDialog();
}}
Is there a way to keep these methods static like this?
ShowRelatedDocumentsVM.ShowRelatedDocument(A objA);
ShowRelatedDocumentsVM.ShowRelatedDocument(B objB);
I didn't find anything about ViewModels and static methods. Can a VM create a instance of itself and show his View (here a window)?
Or is the better way to pass the objects as parameter to the constructor of the VM like this?
public ShowRelatedDocumentsVM(A objA)
{
HandleA(obj A)
ShowRelatedDocuments srd = new ShowRelatedDocuments();
srd.DataContext = this;
srd.ShowDialog();
}
public ShowRelatedDocumentsVM(B objB)
{
HandleB(objB);
ShowRelatedDocuments srd = new ShowRelatedDocuments();
srd.DataContext = this;
srd.ShowDialog();
}
Or are both ways wrong, cause i breach the MVVM pattern due creating the view in the viewmodel?
Thx in advance.
How to display dialogs is one of the areas of MVVM that is not immediately clear, and there are a number of ways the behaviour can be achieved.
I would suggest using either a mediator (as described here) or by injecting a dependency on the view model that controls dialogs:
interface IDialogService
{
void ShowRelatedDocumentsA(A a);
}
...
class MyViewModel
{
private IDialogService _dialogService
public MyViewModel(IDialogService dialogService) { _dialogService = dialogService; }
public void DoSomething()
{
_dialogService.ShowDialog(...);
}
}
Either of these can will permit you to control the creation of the view outside of the view model, and will remove any explicit references from VM -> V.
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