Develop Reference

How to automatically snap a WPF window to an edge of the screen while retaining its size?

As the application starts, I'd like my WPF window to automatically snap to the right edge of the screen. Is there a way to do that? I also want to be able to retain its dimensions. So, unlike the snapping behavior that happens when you drag a window to the edge of the screen, causing the window to resize to either a portion of the screen or full screen, I want my window to simply snap to the edge at a certain location by default or if dragged by the user to a specific location afterwards, without resizing. I still want to retain the ability of the user to drag the window away from the edge.
Is there anything like that already implemented or would I have to create my own behavior schema? I tried numerous search keyword combinations, but couldn't find anything similar to what I'm doing. Some of the searches included disabling snapping behavior or providing snapping behavior, but nothing in the way I described above.
EDIT:
I haven't been able to find a ready solution, so I wrote my own. This solution is based on BenVlodgi's suggestions, so I thank him for helping me out. This is a very rough implementation and still requires a lot of polishing and better code techniques, but it works and it's a good base for anyone wanting to try this. It's incredibly simple and works very well with WPF. The only limitation of this implementation is that I haven't tried getting it to work with two screens yet, but it's incredibly simple (I'm just not going to have time for it and I don't need that functionality at this point). So, here's the code and I hope that it helps someone out there:
public partial class MainWindow : Window
{
// Get the working area of the screen. It excludes any dockings or toolbars, which
// is exactly what we want.
private System.Drawing.Rectangle screen =
System.Windows.Forms.Screen.PrimaryScreen.WorkingArea;
// This will be the flag for the automatic positioning.
private bool dragging = false;
// The usual initialization routine
public MainWindow()
{
InitializeComponent();
}
// Wait until window is lodaded, but prior to being rendered to set position. This
// is done because prior to being loaded you'll get NaN for this.Height and 0 for
// this.ActualHeight.
private void Window_Loaded(object sender, RoutedEventArgs e)
{
// Sets the initial position.
SetInitialWindowPosition();
// Sets the monitoring timer loop.
InitializeWindowPositionMonitoring();
}
// Allows the window to be dragged where the are no other controls present.
// PreviewMouseButton could be used, but then you have to do more work to ensure that if
// you're pressing down on a button, it executes its routine if dragging was not performed.
private void Window_MouseDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
// Set the dragging flag to true, so that position would not be reset automatically.
if (e.ChangedButton == System.Windows.Input.MouseButton.Left)
{
dragging = true;
this.DragMove();
}
}
// Similar to MouseDown. We're setting dragging flag to false to allow automatic
// positioning.
private void Window_MouseUp(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
if (e.ChangedButton == System.Windows.Input.MouseButton.Left)
{
dragging = false;
}
}
// Sets the initial position of the window. I made mine static for now, but later it can
// be modified to be whatever the user chooses in the settings.
private void SetInitialWindowPosition()
{
this.Left = screen.Width - this.Width;
this.Top = screen.Height / 2 - this.Height / 2;
}
// Setup the monitoring routine that automatically positions the window based on its location
// relative to the working area.
private void InitializeWindowPositionMonitoring()
{
var timer = new System.Windows.Threading.DispatcherTimer();
timer.Tick += delegate
{
// Check if window is being dragged (assuming that mouse down on any portion of the
// window is connected to dragging). This is a fairly safe assumption and held
// true thus far. Even if you're not performing any dragging, then the position
// doesn't change and nothing gets reset. You can add an extra check to see if
// position has changed, but there is no significant performance gain.
// Correct me if I'm wrong, but this is just O(n) execution, where n is the number of
// ticks the mouse has been held down on that window.
if (!dragging)
{
// Checking the left side of the window.
if (this.Left > screen.Width - this.Width)
{
this.Left = screen.Width - this.Width;
}
else if (this.Left < 0)
{
this.Left = 0;
}
// Checking the top of the window.
if (this.Top > screen.Height - this.Height)
{
this.Top = screen.Height - this.Height;
}
else if (this.Top < 0)
{
this.Top = 0;
}
}
};
// Adjust this based on performance and preference. I set mine to 10 milliseconds.
timer.Interval = new TimeSpan(0, 0, 0, 0, 10);
timer.Start();
}
}
Make sure that your window has the following:
MouseDown="Window_MouseDown"
MouseUp="Window_MouseUp"
WindowStartupLocation="Manual"
Loaded="Window_Loaded"
Also, this doesn't work well with Windows native components of the window, such as the top bar, so I disable the style and create my own (which is actually good for me, since I don't want the windows style for this):
WindowStyle="None"

I don't like the polling approach, but it's been excessively difficult to find a better solution that is still simple in WPF, so I'm gonna post my own.
The solution that I found is actually quite simple, in that it reimplements the behaviour of the DragMove() method of the window, which gives you the option to change the window position while it's being dragged. The following code reimplements DragMove() by storing the distance between the top left corner of the window and the mouse cursor.
public partial class MainWindow : Window
{
// this is the offset of the mouse cursor from the top left corner of the window
private Point offset = new Point();
public MainWindow()
{
InitializeComponent();
}
private void OnMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
Point cursorPos = PointToScreen(Mouse.GetPosition(this));
Point windowPos = new Point(this.Left, this.Top);
offset = (Point)(cursorPos - windowPos);
// capturing the mouse here will redirect all events to this window, even if
// the mouse cursor should leave the window area
Mouse.Capture(this, CaptureMode.Element);
}
private void OnMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
Mouse.Capture(null);
}
private void OnMouseMove(object sender, MouseEventArgs e)
{
if (Mouse.Captured == this && Mouse.LeftButton == MouseButtonState.Pressed)
{
Point cursorPos = PointToScreen(Mouse.GetPosition(this));
double newLeft = cursorPos.X - offset.X;
double newTop = cursorPos.Y - offset.Y;
// here you can change the window position and implement
// the snapping behaviour that you need
this.Left = newLeft;
this.Top = newTop;
}
}
}
Now you could implement the snapping / sticky window behaviour like this: The window will stick to the edge of the screen if it's within a range of 25 pixels (plus or minus).
int snappingMargin = 25;
if (Math.Abs(SystemParameters.WorkArea.Left - newLeft) < snappingMargin)
newLeft = SystemParameters.WorkArea.Left;
else if (Math.Abs(newLeft + this.ActualWidth - SystemParameters.WorkArea.Left - SystemParameters.WorkArea.Width) < snappingMargin)
newLeft = SystemParameters.WorkArea.Left + SystemParameters.WorkArea.Width - this.ActualWidth;
if (Math.Abs(SystemParameters.WorkArea.Top - newTop) < snappingMargin)
newTop = SystemParameters.WorkArea.Top;
else if (Math.Abs(newTop + this.ActualHeight - SystemParameters.WorkArea.Top - SystemParameters.WorkArea.Height) < snappingMargin)
newTop = SystemParameters.WorkArea.Top + SystemParameters.WorkArea.Height - this.ActualHeight;
The downside of this approach is that the snapping will not work, if the window is being dragged on the title bar, because that doesn't fire the OnMouseLeftButtonDown event (which I don't need, because my window is borderless). Maybe it will still help someone.

There is no API calls you can make (as far as I've seen) to use the Windows snapping features, however you could just get the System.Windows.Forms.Screen.PrimaryScreen.WorkingArea of the screen and set your Top, Left, Height and Width Properties of your Window accordingly.
Edit: The above suggestion does require Forms, which you probably don't want. I believe the WPF equivalent is System.Windows.SystemParameters.WorkArea

How do I move a game piece(control) during runtime?

I am doing a simple C# program of the game Knights Tour in C# the hard way to learn all I can of C#. I have a board and a knight piece and the knight is a custom panel with the picture of the knight.
What I am attempting to do is allow the user to click and drag the knight piece control during run time (exactly the way you can move the control in design time to place it), but for whatever reason I have getting some very undesired results.
private void KTmain_Load(object sender, EventArgs e)
{
boolKnightmoves = false;
}
private void kpcKnight_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{
switch (e.Button)
{
case MouseButtons.Left:
boolKnightmoves = true;
intCurMouseX = e.X;
intCurMouseY = e.Y;
break;
case MouseButtons.Right:
case MouseButtons.Middle:
case MouseButtons.XButton1:
case MouseButtons.XButton2:
case MouseButtons.None:
default:
boolKnightmoves = false;
break;
}
}
private void kpcKnight_MouseUp(object sender, MouseEventArgs e)
{
switch (e.Button)
{
case MouseButtons.Left:
boolKnightmoves = false;
break;
case MouseButtons.Right:
case MouseButtons.Middle:
case MouseButtons.XButton1:
case MouseButtons.XButton2:
case MouseButtons.None:
default:
boolKnightmoves = false;
break;
}
}
private void kpcKnight_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
{
if (boolKnightmoves)
{
txtTest.Text = e.X + ", " + e.Y;
txtTest.Text += Environment.NewLine + kpcKnight.Location;
int i = e.X == intCurMouseX ? 0 : e.X > intCurMouseX ? 1 : -1;
int j = e.Y == intCurMouseY ? 0 : e.Y > intCurMouseY ? 1 : -1;
txtTest.Text += Environment.NewLine + i.ToString() + ", " + j.ToString();
kpcKnight.Location = new Point(
kpcKnight.Location.X + i,
kpcKnight.Location.Y + j);//e.Y == intCurMouseY ? 0 : e.Y > intCurMouseY ? 1 : -1);
//e.X == intCurMouseX ? 0 : e.X > intCurMouseX ? 1 : -1,
intCurMouseX = e.X;
intCurMouseY = e.Y;
}
}
private void kpcKnight_MouseLeave(object sender, EventArgs e)
{
boolKnightmoves = false;
}
private void kpcKnight_LocationChanged(object sender, EventArgs e)
{
kpcKnight.Refresh();
}
I see no real reason why this code would not do the same thing, but I am obviously missing something. When I click on the knight and move it, it does not move at the same speed as the mouse, it moves much slower. It also fades while moving it where you cant see it.
How do i make the knight piece move the same way it does in the form designer in a way that makes sense moving a chess piece across a chess board?
Any assistance will be appreciated.
I updated the code a bit and it does seem to help, but the animation aspect of it is still quite choppy and the panel picks up a bit of the background as it moves and placed.
how does it do it in the form designer so smoothly?
private void kpcKnight_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
{
if (boolKnightmoves)
{
txtTest.Text = e.X + ", " + e.Y;
txtTest.Text += Environment.NewLine + kpcKnight.Location;
int x = kpcKnight.Location.X + e.X - intCurMouseX;
int y = kpcKnight.Location.Y + e.Y - intCurMouseY;
kpcKnight.Location = new Point(x, y);
kpcKnight.Refresh();
/*
int i = e.X == intCurMouseX ? 0 : e.X > intCurMouseX ? 1 : -1;
int j = e.Y == intCurMouseY ? 0 : e.Y > intCurMouseY ? 1 : -1;
txtTest.Text += Environment.NewLine + i.ToString() + ", " + j.ToString();
kpcKnight.Location = new Point(
kpcKnight.Location.X + i,
kpcKnight.Location.Y + j);//e.Y == intCurMouseY ? 0 : e.Y > intCurMouseY ? 1 : -1);
//e.X == intCurMouseX ? 0 : e.X > intCurMouseX ? 1 : -1,
intCurMouseX = e.X;
intCurMouseY = e.Y;*/
}
}

Why don't you just set the Knights position the same as the mouse position in the Mouse_Move method?
Something like:
kpcKnight.Location = new Point(e.X, e.Y)
Obviously you can make it move nicer by knowing where the Knight got initially clicked and move smoothly according to that delta without having the initial jitter.

It's drawing so slowly because you're moving a panel with every mouse motion. That means the form needs to redraw itself several times, and a complete form redraw is expensive.
The basic solution is - don't change the panel's position that often.
I see two ways of doing it.
The first way is simple, but may look jerky. Don't draw every mouse movement. Draw every 5th one, or some arbitrary number you set. Basically keep a counter that you set to 0 on mouse down, and every time you get a mouse move, check if ++counter % n == 0. If so, do the actual drawing. Just make sure to draw on mouse up, as well. Or, just as effectively, only draw when one mouse movement is a certain number of points in x or y away from the previous position.
The second idea is more complicated, but should be the fastest, least jerky thing you can do. Don't move the panel at all while the mouse is moving. Instead, make the panel disappear, and set the cursor to a custom cursor showing the knight. On mouse up, reset the cursor, move the panel and make it visible. This should be about as fast as you can get.
Edit
I'm going to go into the realm of metaphor here, just to get a few things across. Animation is an aspect of C#, but it's not one of the features of it. (i.e., you can accomplish it, but it doesn't have much to make these things easy on you, and it's not a simple key feature.) So... metaphor.
Think of the controls you've placed on your screen to make your board and knight as a bunch of cars packed tight into a parking lot. All you're doing is looking at the parking lot from a helicopter high up. What you're telling the runtime to do, every time you move a component, is completely bulldoze the cars off the parking lot, then place them with a crane in new positions. That's the scope that I'm talking about when I say "a complete form redraw is expensive."
Instead, what you want to do from your helicopter is percieve that the cars are magically changing position. Rather than have a bulldozer and a crane, just blank out your helicopter view, take a snapshot of what you want to see, and change the snapshot little by little, until it looks the way you want. That's what the second suggestion is - don't consantly force the form to recalculate each component's look. Instead, put the animation above the form, and only change the form when you're done.
The keywords you want to search for are "gdi+" (the .NET graphics package), and animation. MouseMove wouldn't hurt, and Paint is the event where you may need to do the animations. There are plenty of places you can find, though How to draw rectangle on MouseDown/Move c# could be a good start.
Edit #2
One last suggestion I have. You can use this in addition to any animation you make. Functionally, it satisfies your requirements on its own, but it's probably not what you're looking for. Track the mouse, and modify the background image of whatever panel the mouse is hovering over. In that case, you'll want to be looking at ImageList, and simple properties like your control BackgroundImage. This could be nice even if you do have a better animation working. You can easily use this to show "the knight can't move here" or "the knight has already moved here." Since it's changing your component instead of moving your component, it's really inexpensive to do, and can easily keep up with your mouse movement. It may be sufficient to imply the movement you want, and it will teach you aspects of winforms that are more important and frequently used than animation and GDI+ rendering.

All you need is:
private int intCurMouseX, intCurMouseY;
private void kpcKnight_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{
if (e.Button == System.Windows.Forms.MouseButtons.Left)
{
intCurMouseX = e.X;
intCurMouseY = e.Y;
}
}
private void kpcKnight_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
{
if (e.Button == System.Windows.Forms.MouseButtons.Left)
{
kpcKnight.Location = new Point(
kpcKnight.Location.X + (e.X - intCurMouseX),
kpcKnight.Location.Y + (e.Y - intCurMouseY));
}
}

Transparency in .Net is a bit of a misnomer. The background simply becomes the color of the parent container. When your controls overlap with each, as will likely be the case when the pieces are dragged across the board, then you'll see the "background" of the piece because controls are rectangular. One option would be to actually CLIP the PictureBox so it is an irregular shape. This can be accomplished by creating a Region() from a GraphicsPath() and then assigning that to the Region() property of the PictureBox. A simplistic approach is to use whatever color is in the top left of the Image and use that as the "mask" color. Next walk the entire image and only add locations where pixels are not the mask color to the GraphicsPath(). This only needs to be done once with the PictureBox after the Image() has been assigned. Again, this approach requires that the "background" of your image (the parts you do NOT want to keep) are all the same color, AND also that this color is not present anywhere as part of the image you want to keep. Here's an example:
private void Form1_Load(object sender, EventArgs e)
{
// perform this for all your PictureBox pieces:
this.ClipPictureBoxPiece(this.kpcKnight);
// ...
// ...
}
private void ClipPictureBoxPiece(PictureBox pb)
{
if (pb != null && pb.Image != null)
{
System.Drawing.Drawing2D.GraphicsPath gp = new System.Drawing.Drawing2D.GraphicsPath();
using (Bitmap bmp = new Bitmap(pb.Image))
{
Color mask = bmp.GetPixel(0, 0);
for (int x = 0; x < bmp.Width; x++)
{
for (int y = 0; y < bmp.Height; y++)
{
if (!bmp.GetPixel(x, y).Equals(mask))
{
gp.AddRectangle(new Rectangle(x, y, 1, 1));
}
}
}
}
pb.Region = new Region(gp);
}
}

Performance issue of DrawingVisual following cursor while using onMouseMove event

I'm busy with a small application in which I want to display information at the location of the cursor when it hoovers over a Canvas. The Canvas in question is a custom one (inherited from Canvas) which provides functionality to add DrawingVisuals (as shown in basically every tutorial on displaying large amounts of geometric shapes on a canvas).
I would like to display a vertical line and horizontal line as well as the local coordinates (p in the code below) which are directly derived from the canvas coordinates (v). At the moment I'm rendering these objects at position (0,0) and use offset during the OnMouseMove event to update their location.
The horizontal and vertical lines are rendered in the DrawingVisual _cursor and the location in local y,z-coordinates in _info.
private void oCanvas_MouseMove(object sender, MouseEventArgs e)
{
#region 1. Get location data
System.Windows.Vector v = (System.Windows.Vector)e.GetPosition(oCanvas);
// point in YZ coordinates
BSMath.DoubleXY p = new BSMath.DoubleXY();
p.X = (oCanvas.OriginY - v.Y) / oCanvas.ZoomFactor;
p.Y = (oCanvas.OriginX - v.X) / oCanvas.ZoomFactor;
#endregion
#region 2. Update cursor and info
if (oSettings.ShowInformation)
{
_info.Info = p.X.ToString("0.0") + " | " + p.Y.ToString("0.0");
_info.Render(0, 0);
_info.Visual.Offset = v;
}
// move cursor
_cursor.Visual.Offset = v;
}
Using the mousemove event seems to be creating a lot of overhead and I can see that there are issues tracking the mouse movements when I move the mouse quickly.
Can anyone recommend a better way of creating the same effect?
example http://www.iccg.be/test/images/canvas.jpg
Edit:
I investigated it a bit further and the problem seems to occur when the resolution of the canvas is bigger. If it is a 600x400 canvas then there is no delay, but when it is around 1000x800 I get the problem with delays when hoovering. The performance also improves if I use user drawn crosshairs instead of the lines that have the full width/ height of the canvas.

I recently have built something similar and haven't had any performance issues.
Did it the very simple way by adding the stuff directly on the canvas.
The drawn items are in a second canvas behind the mouse position canvas. Both reside in a Grid.
This is for sure not the most sophisticated way to solve this, but it works quite well for me.
Here's the code:
private Point _previous;
private Point _current;
private Line _xLine;
private Line _yLine;
private TextBlock _displayTextBlock;
private void Canvas_MouseMove(object sender, MouseEventArgs e)
{
_current = e.GetPosition(myCanvas);
if (_previous != _current)
{
if (_xLine == null)
{
_xLine = new Line() {X1 = 0, X2 = myCanvas.ActualWidth, Stroke = new SolidColorBrush(Colors.Black)};
_yLine = new Line() {Y1 = 0, Y2 = myCanvas.ActualHeight, Stroke = new SolidColorBrush(Colors.Black)};
_displayTextBlock = new TextBlock();
myCanvas.Children.Add(_xLine);
myCanvas.Children.Add(_yLine);
myCanvas.Children.Add(_displayTextBlock);
}
_displayTextBlock.SetValue(Canvas.TopProperty, _current.Y);
_displayTextBlock.SetValue(Canvas.LeftProperty, _current.X);
_displayTextBlock.Text = _current.X.ToString() + " | " + _current.Y.ToString();
_xLine.Y1 = _current.Y;
_xLine.Y2 = _current.Y;
_yLine.X1 = _current.X;
_yLine.X2 = _current.X;
_previous = _current;
}
}

Make Buttons/Labels on windows form bigger/move position on maximise?

I am developing a clock Timer. It is working fine however I am having a issue when the form which is normally small to sit in the corner of the screen out of the way is maximised. Is there a way when it is maximised that I can move the location of the Activity (where all the info is enetered) - I can move that start pause and stop/reset button and I can also move the labels which countdown the time and make them a lot bigger on the maximised display. I have two images - background small and background large which are changing fine on the maximise - I used the code below too hook into the size change event - however the commented out is not working - it does not let be hard code the X,Y co-ordinates of where i would like the activity on maximise...is there something I am missing?
Many Thanks - Colly.
private void CountDownTimer_SizeChanged(object sender, EventArgs e)
{
Image Max = new Bitmap(#"C:\Users\colinmck\Desktop\Timer\CountDownTimer\IgnitionTeamLRG.bmp");
Image Min = new Bitmap(#"C:\Users\colinmck\Desktop\Timer\CountDownTimer\IgnitionTeamSML.bmp");
if (WindowState == FormWindowState.Maximized)
{
BackgroundImage = Max;
//Not Working!!!!!!!!!!!!!
//Activity.Location.X = 60;
//Activity.Location.Y = 65;
}
else
{
BackgroundImage = Min;
}
}

Location.X and Location.Y are read only properties. You should try...
Activity.Location = new Point(60, 65);
Perhaps also take a look into the Anchor property for auto resizing of controls: http://www.tutorialized.com/view/tutorial/C-Resizing-controls-with-form-Anchor-property/52689

How can I check that a window is fully visible on the user's screen?

Is there a way to check that a WinForm is fully visible on the screen (eg is not out of bounds of the screen?)
I've tried using SystemInformation.VirtualScreen for this, which works great as long as the virtual screen is a rectangle, but as soon as it's not (eg 3 screens in a L shape), SystemInformation.VirtualScreen returns the smallest rectangle containing all the visible pixels (so a window on the upper right corner of the L won't be visible although it's in the virtual screen)
The reason I'm trying to achieve this is that I'd like my program to open its child windows in the last location they were on, but I don't want those window to be out of view if the user changes is setup (eg unplugs the extra screen from his laptop)

Here's how I eventually did it :
bool isPointVisibleOnAScreen(Point p)
{
foreach (Screen s in Screen.AllScreens)
{
if (p.X < s.Bounds.Right && p.X > s.Bounds.Left && p.Y > s.Bounds.Top && p.Y < s.Bounds.Bottom)
return true;
}
return false;
}
bool isFormFullyVisible(Form f)
{
return isPointVisibleOnAScreen(new Point(f.Left, f.Top)) && isPointVisibleOnAScreen(new Point(f.Right, f.Top)) && isPointVisibleOnAScreen(new Point(f.Left, f.Bottom)) && isPointVisibleOnAScreen(new Point(f.Right, f.Bottom));
}
There might be some false positive if the user has a "hole" in his display setup (see example below) but I don't think any of my users will ever be in such a situation :)
[1]
[2][X][3]

Here's how I would do it:
This will move the control (form) inside the Display bounds as close as it can to the original location.
private void EnsureVisible(Control ctrl)
{
Rectangle ctrlRect = ctrl.DisplayRectangle; //The dimensions of the ctrl
ctrlRect.Y = ctrl.Top; //Add in the real Top and Left Vals
ctrlRect.X = ctrl.Left;
Rectangle screenRect = Screen.GetWorkingArea(ctrl); //The Working Area fo the screen showing most of the Ctrl
//Now tweak the ctrl's Top and Left until it's fully visible.
ctrl.Left += Math.Min(0, screenRect.Left + screenRect.Width - ctrl.Left - ctrl.Width);
ctrl.Left -= Math.Min(0, ctrl.Left - screenRect.Left);
ctrl.Top += Math.Min(0, screenRect.Top + screenRect.Height - ctrl.Top - ctrl.Height);
ctrl.Top -= Math.Min(0, ctrl.Top - screenRect.Top);
}
Of course to answer your original question instead of moving the control you could just check if any of the 4 Math.Min's returned something other than 0.

This is my solution. It solves the "hole" problem.
/// <summary>
/// True if a window is completely visible
/// </summary>
static bool WindowAllVisible(Rectangle windowRectangle)
{
int areaOfWindow = windowRectangle.Width * windowRectangle.Height;
int areaVisible = 0;
foreach (Screen screen in Screen.AllScreens)
{
Rectangle windowPortionOnScreen = screen.WorkingArea;
windowPortionOnScreen.Intersect(windowRectangle);
areaVisible += windowPortionOnScreen.Width * windowPortionOnScreen.Height;
if (areaVisible >= areaOfWindow)
{
return true;
}
}
return false;
}

I was trying to do this exact same thing detect if the window opened off screen then accordingly reposition it to the nearest location where it was previously found at. I look all over the internet and nothing worked from all the solutions people offered.
So i took it upon myself to make my own class that does just exactly this and it works 100%.
Here is my code
public static class ScreenOperations
{
public static bool IsWindowOnAnyScreen(Window Window, short WindowSizeX, short WindowSizeY, bool AutoAdjustWindow)
{
var Screen = System.Windows.Forms.Screen.FromHandle(new WindowInteropHelper(Window).Handle);
bool LeftSideTest = false, TopSideTest = false, BottomSideTest = false, RightSideTest = false;
if (Window.Left >= Screen.WorkingArea.Left)
LeftSideTest = true;
if (Window.Top >= Screen.WorkingArea.Top)
TopSideTest = true;
if ((Window.Top + WindowSizeY) <= Screen.WorkingArea.Bottom)
BottomSideTest = true;
if ((Window.Left + WindowSizeX) <= Screen.WorkingArea.Right)
RightSideTest = true;
if (LeftSideTest && TopSideTest && BottomSideTest && RightSideTest)
return true;
else
{
if (AutoAdjustWindow)
{
if (!LeftSideTest)
Window.Left = Window.Left - (Window.Left - Screen.WorkingArea.Left);
if (!TopSideTest)
Window.Top = Window.Top - (Window.Top - Screen.WorkingArea.Top);
if (!BottomSideTest)
Window.Top = Window.Top - ((Window.Top + WindowSizeY) - Screen.WorkingArea.Bottom);
if (!RightSideTest)
Window.Left = Window.Left - ((Window.Left + WindowSizeX) - Screen.WorkingArea.Right);
}
}
return false;
}
}
Usage: ScreenOperations.IsWindowOnAnyScreen(WPFWindow, WPFWindowSizeX, WPFWindowSizeY, true);
this will check if the window is offscreen at all, that being 1 pixel under the taskbar or 1 pixel off the users current monitor.
It detects which monitor the window if on first so it should work with multi-monitors.
this method returns true if the window is on the screen and false if its not.
The last parameter is for auto adjusting the window to the nearest part on the screen for you. if you put false for that parameter it will not adjust the window for you.
So this is a complete WPF solution to this issue, and WinForm converting should be easy if you know how to do it, Change Window to Form and FromHandle(Form.Handle) should work.

Check whether Screen.AllScreens.Any(s => s.WorkingArea.Contains(rect))