WPF Window positioning / re-sizing with it's DPI independent scaling had always been an issue for me(especially when you want to animate the movement / size changes smoothly respecting monitor DPI and multi-monitor setups)
I did write a custom helper class to help animate Window dimensions which might help you as well.
The main class(NativeWindowSizeManager):
using System;
using System.Diagnostics.CodeAnalysis;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Interop;
using System.Windows.Media;
/// <summary>
/// C Enumerator to Represent Special Window Handles
/// </summary>
public enum SpecialWindowHandles {
kHwndTop = 0,
kHwndBottom = 1,
kHwndTopmost = -1,
kHwndNotopmost = -2
}
/// <summary>
/// C Enumerator to Set Window Position Flags
/// </summary>
public enum SetNativeWindowPosition {
kNoSize = 0x0001,
kNoMove = 0x0002,
kNoZOrder = 0x0004,
kNoRedraw = 0x0008,
kNoActivate = 0x0010,
kDrawFrame = 0x0020,
kFrameChanged = 0x0020,
kShowWindow = 0x0040,
kHideWindow = 0x0080,
kNoCopyBits = 0x0100,
kNoOwnerZOrder = 0x0200,
kNoReposition = 0x0200,
kNoSendChanging = 0x0400,
kDeferErase = 0x2000,
kAsyncWindowPos = 0x4000
}
/// <summary>
/// Class to perform Window Resize Animations
/// </summary>
public class NativeWindowSizeManager {
#region Member Variables
/// <summary>
/// Attached Dependency Property for Native Window Height
/// </summary>
public static readonly
DependencyProperty NativeWindowHeightProperty = DependencyProperty.RegisterAttached(
"NativeWindowHeight",
typeof(double),
typeof(Window),
new PropertyMetadata(OnNativeDimensionChanged));
/// <summary>
/// Attached Dependency Property for Native Window Width
/// </summary>
public static readonly
DependencyProperty NativeWindowWidthProperty = DependencyProperty.RegisterAttached(
"NativeWindowWidth",
typeof(double),
typeof(Window),
new PropertyMetadata(OnNativeDimensionChanged));
/// <summary>
/// Attached Dependency Property for Native Window Left
/// </summary>
public static readonly
DependencyProperty NativeWindowLeftProperty = DependencyProperty.RegisterAttached(
"NativeWindowLeft",
typeof(double),
typeof(Window),
new PropertyMetadata(OnNativeDimensionChanged));
/// <summary>
/// Attached Dependency Property for Native Window Top
/// </summary>
public static readonly
DependencyProperty NativeWindowTopProperty = DependencyProperty.RegisterAttached(
"NativeWindowTop",
typeof(double),
typeof(Window),
new PropertyMetadata(OnNativeDimensionChanged));
/// <summary>
/// Private member holding Dpi Factor
/// </summary>
private static double? _dpiFactor;
#endregion
#region Constructors
#endregion
#region Commands & Properties
#endregion
#region Methods
/// <summary>
/// Sets the native height.
/// </summary>
/// <param name="element">The element.</param>
/// <param name="value">The value.</param>
public static void SetNativeWindowHeight(UIElement element, double value) {
element.SetValue(NativeWindowHeightProperty, value);
}
/// <summary>
/// Gets the native height.
/// </summary>
/// <param name="element">The element.</param>
/// <returns>Native Height in pixels</returns>
public static double GetNativeWindowHeight(UIElement element) {
return (double)element.GetValue(NativeWindowHeightProperty);
}
/// <summary>
/// Sets the native width.
/// </summary>
/// <param name="element">The element.</param>
/// <param name="value">The value.</param>
public static void SetNativeWindowWidth(UIElement element, double value) {
element.SetValue(NativeWindowWidthProperty, value);
}
/// <summary>
/// Gets the native width.
/// </summary>
/// <param name="element">The element.</param>
/// <returns>Native Width in pixels</returns>
public static double GetNativeWindowWidth(UIElement element) {
return (double)element.GetValue(NativeWindowWidthProperty);
}
/// <summary>
/// Sets the native left.
/// </summary>
/// <param name="element">The element.</param>
/// <param name="value">The value.</param>
public static void SetNativeWindowLeft(UIElement element, double value) {
element.SetValue(NativeWindowLeftProperty, value);
}
/// <summary>
/// Gets the native left.
/// </summary>
/// <param name="element">The element.</param>
/// <returns>Native Left in pixels</returns>
public static double GetNativeWindowLeft(UIElement element) {
return (double)element.GetValue(NativeWindowLeftProperty);
}
/// <summary>
/// Sets the native top.
/// </summary>
/// <param name="element">The element.</param>
/// <param name="value">The value.</param>
public static void SetNativeWindowTop(UIElement element, double value) {
element.SetValue(NativeWindowTopProperty, value);
}
/// <summary>
/// Gets the native top.
/// </summary>
/// <param name="element">The element.</param>
/// <returns>Native Top in pixels</returns>
public static double GetNativeWindowTop(UIElement element) {
return (double)element.GetValue(NativeWindowTopProperty);
}
/// <summary>
/// Method to Get Dpi Factor
/// </summary>
/// <param name="window">Window Object</param>
/// <returns>Dpi Factor</returns>
public static double GetDpiFactor(Visual window) {
HwndSource windowHandleSource = PresentationSource.FromVisual(window) as HwndSource;
if (windowHandleSource != null && windowHandleSource.CompositionTarget != null) {
Matrix screenmatrix = windowHandleSource.CompositionTarget.TransformToDevice;
return screenmatrix.M11;
}
return 1;
}
/// <summary>
/// Method to Retrieve Dpi Factor for Window
/// </summary>
/// <param name="window">Requesting Window</param>
/// <param name="originalValue">Dpi Independent Unit</param>
/// <returns>Pixel Value</returns>
private static int ConvertToDpiDependentPixels(Visual window, double originalValue) {
if (_dpiFactor == null) {
_dpiFactor = GetDpiFactor(window);
}
return (int)(originalValue * _dpiFactor);
}
/// <summary>
/// Handler For all Attached Native Dimension property Changes
/// </summary>
/// <param name="obj">Dependency Object</param>
/// <param name="e">Property Arguments</param>
private static void OnNativeDimensionChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e) {
var window = obj as Window;
if (window == null)
return;
IntPtr handle = new WindowInteropHelper(window).Handle;
var rect = new Rect();
if (!GetWindowRect(handle, ref rect))
return;
rect.X = ConvertToDpiDependentPixels(window, window.Left);
rect.Y = ConvertToDpiDependentPixels(window, window.Top);
rect.Width = ConvertToDpiDependentPixels(window, window.ActualWidth);
rect.Height = ConvertToDpiDependentPixels(window, window.ActualHeight);
if (e.Property == NativeWindowHeightProperty) {
rect.Height = ConvertToDpiDependentPixels(window, (double)e.NewValue);
} else if (e.Property == NativeWindowWidthProperty) {
rect.Width = ConvertToDpiDependentPixels(window, (double)e.NewValue);
} else if (e.Property == NativeWindowLeftProperty) {
rect.X = ConvertToDpiDependentPixels(window, (double)e.NewValue);
} else if (e.Property == NativeWindowTopProperty) {
rect.Y = ConvertToDpiDependentPixels(window, (double)e.NewValue);
}
SetWindowPos(
handle,
new IntPtr((int)SpecialWindowHandles.kHwndTop),
rect.X,
rect.Y,
rect.Width,
rect.Height,
(uint)SetNativeWindowPosition.kShowWindow);
}
#endregion
#region Native Helpers
[DllImport("user32.dll", SetLastError = true)]
private static extern bool GetWindowRect(IntPtr windowHandle, ref Rect rect);
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool SetWindowPos(
IntPtr windowHandle, IntPtr windowHandleInsertAfter, int x, int y, int cx, int cy, uint windowPositionFlag);
/// <summary>
/// C Structure To Represent Window Rectangle
/// </summary>
[SuppressMessage("Microsoft.StyleCop.CSharp.DocumentationRules", "SA1600:ElementsMustBeDocumented",
Justification = "This is an Implementation for C Struct")]
[StructLayout(LayoutKind.Sequential)]
public struct Rect {
public int X;
public int Y;
public int Width;
public int Height;
}
#endregion
}
Now for your requirement in your Button.Click handler you could have something like:
private void ButtonBase_OnClick(object sender, RoutedEventArgs e) {
var storyBoard = new Storyboard { Duration = new Duration(new TimeSpan(0, 0, 0, 0, 250)) };
// Top
var aniTop = new DoubleAnimationUsingKeyFrames { Duration = new Duration(new TimeSpan(0, 0, 0, 0, 250)) };
aniTop.KeyFrames.Add(new EasingDoubleKeyFrame(Top, KeyTime.FromTimeSpan(new TimeSpan(0, 0, 0, 0, 00))));
aniTop.KeyFrames.Add(new EasingDoubleKeyFrame(10, KeyTime.FromTimeSpan(new TimeSpan(0, 0, 0, 0, 250))));
Storyboard.SetTarget(aniTop, this);
Storyboard.SetTargetProperty(aniTop, new PropertyPath(NativeWindowSizeManager.NativeWindowTopProperty));
storyBoard.Children.Add(aniTop);
// Left
var aniLeft = new DoubleAnimationUsingKeyFrames { Duration = new Duration(new TimeSpan(0, 0, 0, 0, 250)) };
aniLeft.KeyFrames.Add(new EasingDoubleKeyFrame(Left, KeyTime.FromTimeSpan(new TimeSpan(0, 0, 0, 0, 00))));
aniLeft.KeyFrames.Add(new EasingDoubleKeyFrame(10, KeyTime.FromTimeSpan(new TimeSpan(0, 0, 0, 0, 250))));
Storyboard.SetTarget(aniLeft, this);
Storyboard.SetTargetProperty(aniLeft, new PropertyPath(NativeWindowSizeManager.NativeWindowLeftProperty));
storyBoard.Children.Add(aniLeft);
storyBoard.Begin();
}
and it should work fine every-time under all the above mentioned cases.
NativeWindowSizeManager also has a NativeWindowWidth and NativeWindowHeight allowing re-sizing to be animated or like my case to animate a Window re-size while centering to the current window screen.
You can get a demo of this project for your use case: Here
