hi all experts
My trouble likes this:
...
<Canvas.Left>
<MultiBinding Converter="{StaticResource relationToConnectionPointConverter}" Mode="OneWay">
<Binding />
<Binding Path="Left"/>
</MultiBinding>
</Canvas.Left>
<Button.Content>
<MultiBinding Converter="{StaticResource relationToConnectionPointConverter}" Mode="OneWay">
<Binding />
<Binding Path="Left"/>
</MultiBinding>
</Button.Content>
...

The Button's Content shows exactly what i need (The left of a rectangle)
But the Canvas.Left value is always0 (zero) (as the button always anchor the left edge of canvas)
Although two Multibindings are identical.
Furthermore when I set break point in relationToConnectionPointConverter.Convert,
the returned Values are, in all cases, exactly expected

Is it a bug?
Any work around solution?

Please help me!
Thanks in advance.

Nghia Nguyen - FCGV