Question

I use MVVM pattern so my own control contains View and ViewModel.
ViewModel is connected with View by DataContext property. This makes problems with binding. Why?

Assume this situation:
I created new user control – for example – “SuperTextBox”. It have a property “SuperValue”.
And now I do something like that:

<Window>
    <Window.DataContext>
        <vm:WindowViewModel/>
    </Window.DataContext>

    <local:SuperTextBox SuperValue="{Binding Test}"/>
</Window>

I thought that “binding process” joins SuperTextBox.SuperValue with Window.DataContext.Test, but no, ‘binding process” joins SuperTextBox.SuperValue with SuperTextBox.DataContext.Test what is for me unnatural and misleading.

Other controls like “TextBox” I can use in above way because they do not have their DataContext.

How can I use MVVM pattern to creating UserControls keeping natural binding (to DataContext of parent control) ?

Edit:

I got many answers how binding to parent, but I know this earlier. The problem is – how can I create UserControl via MVVM patern (having ViewModel) and stay natural binding – default to parent DataContext.

I want to have ViewMoldel and still can binding like this:

<local:SuperTextBox SuperValue="{Binding Test}"/>

Is it possible?

Answer 1

I feel oddly answering on my question but…
In my own control i did something like that:

<UserControl>
    <Grid>
        <Grid.DataContext>
             <vm:UserControlViewModel />
        </Grid.DataContext>
        // here realy code of control
    </Grid>
</UserControl>

Now I can use “natural” binding outside of control and in control. 🙂