CODEWITHSUNDEEP
c#wpf
jefsmi
jefsmi

Reputation: 731

Issue with setting a custom property in WPF

Let's say I got 2 ViewModels and 1 View

in ViewModel_A I got a costum property class PersonClass PersonClass has some fields

In View_A i'm binding some textboxes to the PersonClass property which is binded two way with datacontext ViewModel_A
In ViewModel_B in want to update the PersonClass property from code.

Whats the best way to do this cause like I'm working at the moment I'm making a new instance of ViewModel_A in ViewModel_B and than set the property PersonClass.

ViewModel_A viewModel_A = new ViewModel_A();

viewModel_A.PersonClass.Name = someString;
viewModel_A.PersonClass.Age = someString;

...

Like I'm doing it now I got 2 different instances of ViewModel_A, so my property PersonClass will never notice any changes...
Whats the best solution to solve this?

Upvotes: 0

Views: 63

Answers (1)

dowhilefor
dowhilefor

Reputation: 11051

Your PersonClass must implement INotifyPropertyChanged and your View must get a viewmodel instance set as the DataContext. One nice way to handle with nested ViewModels, is to use ContentControls This is not necessary of course, but adds a nice way of customization, just switching the sub viewmodel allows changing parts of the UI.

class ViewModel_B
{
    public ViewModel_A MySubViewModel{get;set;}
}

<DataTemplate x:Key="vmaTemplate" DataType="{x:Type ViewModel_A}">
    <TextBlock Text="{Binding PersonClass.Name}"/>
</DataTemplate>

<Grid>
    <ContentControl Content="{Binding MySubViewModel}" 
           ContentTemplate="{StaticTemplate vmaTemplate}"/>
</Grid>

This example assumes, that the Grid has as the DataContext an instance of ViewModel_B.

Upvotes: 1

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