BPASmartClient/BPASmartClient.CustomResource/UserControls/Control/Thermometer.xaml

<UserControl
    x:Class="BPASmartClient.CustomResource.UserControls.Thermometer"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:local="clr-namespace:BPASmartClient.CustomResource.UserControls"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    d:DesignHeight="450"
    d:DesignWidth="800"
    mc:Ignorable="d">
    <Viewbox>
        <Canvas
            Name="canvas1"
            Width="{Binding Width, RelativeSource={RelativeSource AncestorType=UserControl, Mode=FindAncestor}}"
            Height="{Binding Height, RelativeSource={RelativeSource AncestorType=UserControl, Mode=FindAncestor}}" />
    </Viewbox>
</UserControl>