WPF using MVVM: DataBinding with RelativeSource

Question

I have a control and within that control I have a resource with a data tempalte:

  <DataTemplate DataType="{x:Type local:FlowModel}">
    <Image Source="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type vm:MainViewModel}}, Path=MainViewModel.ImagePath}"/>
  </DataTemplate>

 xmlns:vm="clr-namespace:CortexMonitoringTool.ViewModel"

I have vm set to my ViewModel folder, I am implementing mvvm. I cannot get my binding to work and I am unsure why not.

Can some tell me if my relative binding is correct, if it can actually see my property 'ImagePath' in my MainViewModel class?

public String ImagePath
    {
        get
        {
            return _imagePath;
        }
        set
        {
            if (_imagePath == value)
            {
                return;
            }
            _imagePath = value;
            RaisePropertyChanged("ImagePath");
        }
    }

Thank you.

Answer 1

Hi I managed to get it to work.

  <DataTemplate DataType="{x:Type local:FlowModel}">
    <Image Source="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}, Path=DataContext.ImagePath}"/>
  </DataTemplate>

I changed my AncestorTypeto be'Window' which was all ready bound to my MainViewModel and then used 'DataContext.' in my Path to be able to see my property.

Hope this helps someone else!!

Answer 2

you View model is not part of your Visual tree. so the find ancestor type will not work there. and if you find the root parent which is having the datacontext then you can use its property to bind with like.

<Image Source={...... Path=DataContext.MyProperty}"/>