MVVM binding cutom property to view model - xaml

Question

I am new in MVVVM so please forgive me if it is stupid question. I am using this example http://www.codeproject.com/Articles/36848/WPF-Image-Pixel-Color-Picker-Element and included there library to get color of indicated by user pixel of image. it looks nice and dipsalys in rectangle selected color but i neeed to bind the selecteed value to viewmodel.
here is my xaml code:
<Window x:Class="MovieEditor.View.PixelSelector"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:ctrls="clr-namespace:ColorPickerControls;assembly=ColorPickerControls"
xmlns:local="clr-namespace:MovieEditor.MVVMCommon"
Title="FilterDesigner" Height="550" Width="550"
Icon="..\Resources\Images\icon.ico"
xmlns:VM="clr-namespace:MovieEditor.ViewModel">
<Window.DataContext>
<VM:PixelSelectorVM/>
</Window.DataContext>
<Window.Resources>
<local:ColorToBrushConverter x:Key="ColorToBrushConverter"/>
</Window.Resources>
<Grid Background="#FF191919" >
<DockPanel>
<Grid Margin="10,10,10,1">
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition Height="Auto" MinHeight="38"/>
</Grid.RowDefinitions>
<Border BorderBrush="White" BorderThickness="5" Margin="0,39,0,11">
<ctrls:ImageColorPicker Binding.XmlNamespaceManager="{Binding p PixelSelectorVM.MyImageColorPicker, UpdateSourceTrigger=PropertyChanged}"
x:Name="image" Source ="{Binding Frame}" Margin="0,36,0,0"
/>
</Border>
<Border Width="77"
HorizontalAlignment="Center"
BorderBrush="White" BorderThickness="1" Margin="263,2,182,435">
<Rectangle Fill="{Binding ElementName=image, Path=SelectedColor,
Converter={StaticResource ColorToBrushConverter}}" RenderTransformOrigin="0.549,0.429" Margin="1"/>
</Border>
<Button Content="Save" Command="{Binding Save}" Margin="165,0,0,4" Grid.Row="1" HorizontalAlignment="Left" Width="60"/>
<Label Content="Selected pixel color:" HorizontalAlignment="Left" Height="18" Margin="140,11,0,0" VerticalAlignment="Top" Width="110"/>
<Button Content="Cancel" Command="{Binding Cancel}" Margin="0,1,165,4" HorizontalAlignment="Right" Width="60" RenderTransformOrigin="0.5,0.5" Grid.Row="1">
</Button>
</Grid>
</DockPanel>
</Grid>
</Window>
</code>
And here is my view model:
public class PixelSelectorVM : ViewModelBase
{
private BitmapImage frame;
public MainWindowVM parentMainWindowVM;
private ImageColorPicker imageColorPicker;
public ImageColorPicker MyImageColorPicker
{
get
{
return this.imageColorPicker;
}
set
{
this.imageColorPicker = value;
OnPropertyChanged("MyImageColorPicker");
}
}
public BitmapImage Frame
{
get
{
return this.frame;
}
set
{
this.frame = value;
OnPropertyChanged("Frame");
}
}
public PixelSelectorVM(BitmapImage image, MainWindowVM mainWindowVM)
{
this.frame = image;
this.parentMainWindowVM = mainWindowVM;
this.imageColorPicker = new ImageColorPicker();
this.imageColorPicker.Source = image;
}
public PixelSelectorVM() { }
public ICommand Save
{
get
{
return new RelayCommand(SaveExecute);
}
}
public ICommand Cancel
{
get
{
return new RelayCommand(CancelExecute);
}
}
private void SaveExecute()
{
}
private void CancelExecute()
{
}
}
Please suggest me solution how can i pass the selected color to view model

Answer 1

You should be able to bind ImageColorPicker's SelectedColor to ViewModel's Property.
So in XAML add the binding:
SelectedColor="{Binding MySelectedColor, Mode=TwoWay}"
And in VM add the MySelectedColor property:
private Color selectedColor;
public Color MySelectedColor
{
get
{
return this.selectedColor;
}
set
{
this.selectedColor = value;
OnPropertyChanged("MySelectedColor");
}
}
When control's SelectedColor changes, it should automatically update the MySelectedColor in your VM.