WPF Points databinding issue

Question

I am developing interactive chart library...and application, which use it.

In application, I have a ListView with Points of the CurrentItem.

public Point CurrentPoint
  {
   get { return myCurrentPoint; }
   set
   {
    myCurrentPoint = value;
    base.OnPropertyChanged("CurrentPoint");
   }
  }

At the same panel, I have two textboxes for editing point's coordinates:

<TextBox Text="{Binding CurrentPoint.X, Mode=TwoWay}" 
       Grid.Column="1" Grid.Row="0" Width="80" Margin="5"/>

My big problem is, that Point is a structure...so it's passing by value.

If I change X coordinate in textbox...it doesn't change databind Point.

How can I solve this problem?
Should I write my own Point class, and Line class too, because of her Points are PointCollection of Point?

If it's needed, I can post more code :)

Thanks.

Answer 1

Why not create a combined control that changes the Point instead of the x-and y-component of the Point. Then you can bind to your Point-property and binding will work as expected. Furthermore, you have probably a nicer UI.

You can create a UserControl, add two text-boxes and add a DependencyProperty-Point to this control. Everytime the contents of one of the textboxes changes, set the Point-property to its new value.

public class PointInputBox : UserControl{

  public static readonly DependencyProperty PointProperty =
    DependencyProperty.Register("Point", typeof(Point), typeof(PointInputBox), new FrameworkPropertyMetadata(new Point(0,0),FrameworkPropertyMetadataOptions.BindsTwoWayByDefault));


  public Point Point {
    get { return (Point)GetValue(PointProperty); }
    set { SetValue(PointProperty, value); }
  }

  // Add here event handlers for changes of your input boxes and set 
  //  the Point-value accordingly