Question

I would like to make my application on windowsphone remember that I have checked a checkbox the next time it starts. How can I do that by Databinding or MVVM ?

Answer 1

In your View/XAML you will have a CheckBox

When you check/uncheck value you are basically playing with IsChecked property of Checkbox

In the ViewModel create a property let’s say IsChecked and bind the value of checkbox’s checked property like this. This property will be bound to Checkbox in View or in other words CheckBox’s IsChecked property will be set using this property

<CheckBox IsChecked={Binding path=IsChecked}/>

Based On Comment

You will put code above in XAML which is View in MVVM terms and in the ViewModel you will create a Property like this

public bool IsChecked
{
    get
    {
        return yourBoolVariableContainingPropertyValue;
    }
    set
    {
         //load value from last checked/unchcked value
         yourBoolVariableContainingPropertyValue = value;
    }
}

I would suggest you to follow some basic tutorials like Creating your first MVVM silverlight application on windows phone 7.