Should I bind to Properties of my control, or should I update them in OnPropertyChanged?-CodePudding

Let's say I have ControlA, where in code-behind I have some property PropertyA, that are instance properties for bindable properties. I want to channel their values to PropertyB in control ControlB that is declared in XAML.

Now I can bind to property like so:

<ContentView
  ...
  x:Name="Self">

  <ContentView.Content>
    <ControlB
      x:Name="ConB"
      PropertyB="{Binding Source={x:Reference Self}, Path=PropertyA}/>
  </ContentView.Content>
</ContentView>

Or in the code behind like so:

protected override void OnPropertyChanged(string propertyName = null)
{
  if(propertyName == nameof(PropertyA)
  {
    ConB.PropertyB = PropertyA;
  }
}

Is one of the approaches better than the other?

CodePudding user response：

I prefer the first case.

REASON: Put code where it applies, not in a centralized place requiring

if ... elseif ...

That gets messy.

And if you are looking at XAML for ControlB, there is no indication that you also need to go look in cs file, OnPropertyChanged method, to understand what affects it.

The only time I would consider it, is if it was an expression that was difficult to write in XAML. For example, if it depended on some other condition:

if (someSpecialFlag && ... nameof(PropertyA)) ...

In such a case, I would put a prominent comment at the top of the cs code-behind file, alerting anyone who has to maintain the code that something special was done in OnPropertyChanged.

Its also worth looking into Triggers, as a way to represent conditions in XAML.