Is it possible to disable the automatic window-docking feature of Windows 7 in a WPF application?
I recently needed to do this to a custom, resizable ResizeMode = CanResizeWithGrip
WPF window with no window decorations (no title bar and buttons). I used DragMove()
to move the window, and when It is maximized by AeroSnap, the window becomes unmovable and hence locked in place.
I tried Barn Monkey's solution, which partially worked, but it would still show the AeroSnap graphic and resize the app to fullscreen size. I modified it below and now it works as expect: still resizable, but no AeroSnap at all.
void Window1_MouseDown(object sender, MouseButtonEventArgs e)
{
if( e.LeftButton == MouseButtonState.Pressed )
{
// this prevents win7 aerosnap
if( this.ResizeMode != System.Windows.ResizeMode.NoResize )
{
this.ResizeMode = System.Windows.ResizeMode.NoResize;
this.UpdateLayout();
}
DragMove();
}
}
void Window1_MouseUp( object sender, MouseButtonEventArgs e )
{
if( this.ResizeMode == System.Windows.ResizeMode.NoResize )
{
// restore resize grips
this.ResizeMode = System.Windows.ResizeMode.CanResizeWithGrip;
this.UpdateLayout();
}
}
EDIT:
It's been a while since I wrote this, but since people still look at this I'll update it with what I use now. I still use basically the same method for preventing edge snapping and moving my windows, but I now have them packed into custom Behavior<>
classes that I can attach to a Window
or UserControl
. This makes them very easy to use with MVVM (I use Caliburn Micro).
The behavior classes are:
/// <summary>
/// behavior that makes a window/dialog draggable by clicking anywhere
/// on it that is not a control (ie, button)
/// </summary>
public class DragMoveBehavior<T> : Behavior<T> where T : FrameworkElement
{
protected override void OnAttached()
{
AssociatedObject.MouseLeftButtonDown += MouseDown;
base.OnAttached();
}
protected override void OnDetaching()
{
AssociatedObject.MouseLeftButtonDown -= MouseDown;
base.OnDetaching();
}
void MouseDown( object sender, EventArgs ea ) => Window.GetWindow( sender as T )?.DragMove();
}
public class WinDragMoveBehavior : DragMoveBehavior<Window> { }
public class UCDragMoveBehavior : DragMoveBehavior<UserControl> { }
/// <summary>
/// behavior that makes a window/dialog not resizable while clicked. this prevents
/// the window from being snapped to the edge of the screen (AeroSnap). if DragMoveBehavior
/// is also used, this must be attached first.
/// </summary>
/// <typeparam name="T"></typeparam>
public class NoSnapBehavior<T> : Behavior<T> where T : FrameworkElement
{
ResizeMode lastMode = ResizeMode.NoResize;
protected override void OnAttached()
{
AssociatedObject.MouseLeftButtonDown += MouseDown;
AssociatedObject.MouseLeftButtonUp += MouseUp;
base.OnAttached();
}
protected override void OnDetaching()
{
AssociatedObject.MouseLeftButtonDown -= MouseDown;
AssociatedObject.MouseLeftButtonUp -= MouseUp;
base.OnDetaching();
}
/// <summary>
/// make it so the window can be moved by dragging
/// </summary>
void MouseDown( object sender, EventArgs ea )
{
var win = Window.GetWindow( sender as T );
if( win != null && win.ResizeMode != ResizeMode.NoResize )
{
lastMode = win.ResizeMode;
win.ResizeMode = ResizeMode.NoResize;
win.UpdateLayout();
}
}
void MouseUp( object sender, EventArgs ea )
{
var win = Window.GetWindow( sender as T );
if( win != null && win.ResizeMode != lastMode )
{
win.ResizeMode = lastMode;
win.UpdateLayout();
}
}
}
public class WinNoSnapBehavior : NoSnapBehavior<Window> { }
public class UCNoSnapBehavior : NoSnapBehavior<UserControl> { }
I then attach them to my dialog box Views with:
<UserControl ...
xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
xmlns:util:="...">
<i:Interaction.Behaviors>
<util:UCNoSnapBehavior/>
<util:UCDragMoveBehavior/>
</i:Interaction.Behaviors>
...
</UserControl>
And it just works!