Question

All –

I am trying to set public property in VM based on the current item in Observable collection (which is also in VM). So essentially – I want to set shadecolor as Blue or Pink based on the row I am (see sample code below). Also see image of what the end result will look like.

Can somebody please suggest – how I can achieve this – am really stuck with this problem

See sample code below:

Model.cs

public class Model
{
    public Employee empdetails { get; set; }
}

public class Employee
{
    public string fname { get; set; }
    public string lname { get; set; }
    public Enum gender { get; set; }
}

public enum gender
{
    Male,
    Female
}

ViewModel.cs

public class ViewModel
{
    public ObservableCollection<Model> employees {get; set;}
    public myCommand NextCommand { get; set; }
    private Color _shadecolor;

    public Color shadecolor
    {
        get
        {
            return _shadecolor;
        }
        set
        {
            _shadecolor = value;
        }
    }

    public ViewModel()
    {
        employees = new ObservableCollection<Model>()
        {
            #region Populating Emp 1
            new Model()
            {
                empdetails = new Employee()
                {
                    fname = "John",
                    lname = "Smith",
                    gender = gender.Male
                }
            },
            #endregion

            #region Populating Emp 2
            new Model()
            {
                empdetails = new Employee()
                {
                    fname = "Robert",
                    lname = "Ally",
                    gender = gender.Female
                }
            },
            #endregion
        };

        NextCommand = new myCommand(myNextCommandExecute, myCanNextCommandExecute);
    }

    private void myNextCommandExecute(object parameter)
    {

    }

    private bool myCanNextCommandExecute(object parameter)
    {
        return true;
    }
}

View.xaml

<Window x:Class="WpfApplication1.View"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="View" Height="500" Width="500"  WindowStyle="None" AllowsTransparency="True" Background="Transparent">
<Border VerticalAlignment="Top" HorizontalAlignment="Left" BorderBrush="Silver" BorderThickness="2" CornerRadius="15">
    <Border.Background>
        <LinearGradientBrush StartPoint="0.5,0" EndPoint="0.511,0.957">
            <GradientStop Color="LightGray" Offset="0.55" />
            <GradientStop Color="{Binding shadecolor}" Offset="1.3" />
        </LinearGradientBrush>
    </Border.Background>
    <Grid Width="300" Height="300" Margin="3">
        <StackPanel VerticalAlignment="Top" >
            <TextBlock Text="{Binding Path=employees/empdetails.fname}" />
            <Button Command="{Binding NextCommand}" Content="Next" Width="100"></Button>
        </StackPanel>
    </Grid>
</Border>
</Window>

Answer 1

I believe what you want is to bind SelectedItem={Binding SelectedItem} where Selected item is on the view model as well, exposed as an observable property.

public Model SelectedItem
{
   ...
}

I’m not totally sure what you are trying to achieve here though as you don’t have anything in your XAML deriving from Selector, therefore there is no concept of a selected item here.