title: Different size form WPF - Design mode vs Runtime mode
body: <p>I'm sorry for the beginner's question but 'im quite newbie in creating WPF forms. 
  I've some problems to set and viewing correct size of forms in Visual Studio.
  In <em>design mode</em> the size is <strong>larger</strong> than in <em>runtime mode</em>.
  Here the XAML. Any ideas???</p>
  
  <pre><code>&lt;Window
      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:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
      xmlns:local="clr-namespace:EnginedrawWPF"
      xmlns:h="http://helix-toolkit.org/wpf" x:Class="MainWindow"
      mc:Ignorable="d"
      Title="Motore di disegno" Height="400.0" Width="970.0" ResizeMode="NoResize"&gt;
  &lt;Grid Margin="0,0,0,0"&gt;
  
      &lt;h:HelixViewport3D x:Name="helixviewport3dobj"  Height="301" Margin="207,10,10.2,0" h:VerticalAlignment="Top" Foreground="Black" Background="#FFC0E2B5" &gt;
  
          &lt;h:HelixViewport3D.DefaultCamera&gt;
              &lt;PerspectiveCamera Position="0,-3.5,3.5" LookDirection="0,3.5,-3.5" UpDirection="0,0,1" FieldOfView="61" NearPlaneDistance="0.001"/&gt;
          &lt;/h:HelixViewport3D.DefaultCamera&gt;
          &lt;h:SunLight /&gt;
          &lt;h:GridLinesVisual3D Fill="#FFB9B9B9" Thickness="0.01" MinorDistance="0.2" MajorDistance="1"/&gt;
      &lt;/h:HelixViewport3D&gt;
      &lt;Button x:Name="CBlineare" Content="Nuovo tratto lineare" HorizontalAlignment="Left" Height="30" Margin="10,10,0,0" VerticalAlignment="Top" Width="181"/&gt;
      &lt;Button x:Name="CBcurva90" Content="Aggiungi curva 90°" HorizontalAlignment="Left" Height="30" Margin="10,57,0,0" VerticalAlignment="Top" Width="181"/&gt;
      &lt;Button x:Name="CBcurva45" Content="Aggiungi curva 45°" HorizontalAlignment="Left" Height="30" Margin="10,105,0,0" VerticalAlignment="Top" Width="181"/&gt;
  &lt;/Grid&gt; 
  &lt;/Window&gt;
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/3Ee2u.png" rel="noreferrer"><img src="https://i.stack.imgur.com/3Ee2u.png" alt="screenshot"></a> </p>