I've attached some MouseMove and MouseClick events to my program and next up is one of these:
Get "global" mouse movement, so that I can read the mouse location even outside the form.
Prevent my mouse from leaving the form in the first place.
My project is a game so it'd be awesome to prevent the mouse leaving my form like most other games do (ofc. you can move it out if you switch focus with alt+tab fe.) and taking a look at answers to other questions asking for global mosue movement, they seem pretty messy for my needs.
Is there an easy way to prevent my mouse from going outside my form's borders? Or actually to prevent it from going OVER the borders in the first place, I want the mouse to stay inside the client area.
Additional info about the game:
The game is a short, 5-30 seconds long survival game (it gets too hard after 30 seconds for you to stay alive) where you have to dodge bullets with your mouse. It's really annoying when you move your mouse out of the form and then the player (System.Windows.Forms.Panel attached to mouse) stops moving and instantly gets hit by a bullet. This is why preventing mouse from leaving the area would be good.
Late answer but might come in handy. You could subscribe the form to MouseLeave and MouseMove events and handle them like this :
private int X = 0;
private int Y = 0;
private void Form1_MouseLeave(object sender, EventArgs e)
{
Cursor.Position = new Point(X, Y);
}
private void Form1_MouseMove(object sender, MouseEventArgs e)
{
if (Cursor.Position.X < this.Bounds.X + 50 )
X = Cursor.Position.X + 20;
else
X = Cursor.Position.X - 20;
if (Cursor.Position.Y < this.Bounds.Y + 50)
Y = Cursor.Position.Y + 20;
else
Y = Cursor.Position.Y - 20;
}
The above will make sure the mouse cursor never leaves the bounds of the form. Make sure you unsubscribe the events when the game is finished.
Edit :
Hans Passants's answer makes more sense than my answer. Use Cursor.Clip on MouseEnter :
private void Form1_MouseEnter(object sender, EventArgs e)
{
Cursor.Clip = this.Bounds;
}
You could free the cursor in case of any error/crash (I'm sure you could catch'em) :
Cursor.Clip = Rectangle.Empty;
You cannot trap the mouse, that would prevent the user from, say, operating the Start menu. Closest you can get is assigning the Cursor.Clip property. But it is easily defeated by the user pressing Ctrl+Esc for example, there is no notification for this.
Best thing to do is to subscribe the form's Deactivated event, it reliably tells you that the user switched to another program. The Activated event tells you when the user moved back. Of course the user will have few reasons to actually do this when the game score depends on keeping a game object moving. So don't forget to give the user an easy way to pause the game with, say, the Escape key.
I don't know a solution for your exact problem, but I have a completely different idea for you. I don't know how your game works, but based on what you told me, why not make it a step harder: Add borders to the game-area, for example 4 pixels wide rectangles, which you are not allowed to touch. If you touch them, you die and the mouse gets released.
You can use the Cursor class. For example:
int X = Cursor.Position.X;
int Y = Cursor.Position.Y;
As for preventing the user to move the mouse outside the form, the best approach would probably be if you had someway to know what is the coordinates of your form on the screen and attach a MouseMove event, and check if the mouse is inside the form rectangle.
To know the form position on the screen take a look at this question.
I wouldn't recommend the global mouse movement control for two reasons.
It's bad design, you should respect the bounds of the operating system. Make the application full screen if you want this kind of behaviour. The only applications that should perform these kind of operations are "kiosk" mode applications which lock down the entire OS (to prevent operator abuse).
Global key hooks are messy, aren't guaranteed to work and are dangerous because they affect a key part of the operating system (all controls). A bug in your code could result in requiring a reboot on the machine.
That said, last time I checked (a while ago, on Vista) SetWindowsHookEx still works (but its not officially supported IIRC), it's an unmanaged call so you'll have to pinvoke but with it you can refuse to pass on messages that would move the mouse outside of the bounds of your application. I'm not 100% sure if the OS will let you beat it to the cursor control (I've only blocked keyboards before on desktop boxes) but its probably your best shot.
Related
Moving Label inside parent's MouseMove-events causes trailing redraw.
I am (mis)using System.Windows.Forms.Label objects to realize
A more flexible tooltip,
Displaying a cross hair "cursor" extending to the borders of a parent control.
To that end I create the labels as members of the parent control (btw. it's a custom graphics control with mouse wheel zoom, panning etc.), add them to the parent's Controls-list, and move them inside the MouseMove-event of the parent. In order to ensure crisp movement behavior, I even call Label.Refresh when assigning the Location property of the Labels.
void GraphViewMouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
{
if (lastLocation != e.Location)
{
HasMoved = true;
if (IsPanning && e.Button == MouseButtons.Left)
{
if (isSelecting) PerformSelection(e.Location);
else PerformMove(e.Location,lastLocation);
}
lastLocation = e.Location;
if (Width > 0 && Height > 0)
{
PointD pos = CursorPosition;
// nothing interesting, basically like what is done with the crossHair's below
coordinateToolTip.Locate(lastLocation, pos.X, pos.Y);
crossHairX.Location = new Point(lastLocation.X, 0);
crossHairY.Location = new Point(0, lastLocation.Y);
crossHairX.Refresh();
crossHairY.Refresh();
}
}
}
Everything works almost fine (the labels move parallel to the mouse cursor) except that when I move the mouse a little faster, several copies of the Label(s) remain in the client area of the parent for some time like a visual echo.
That is, whereas the redraw of the labels at their new location appears to occur immediately, it seems to take some fraction of a second until the background of the parent (some complicated graphics, the complete redraw of which takes several seconds, but is definitely not redrawn during said simple mouse move) is restored to what has been behind the moving Label(s) originally. This is of course functionally irrelevant, but it simply looks ugly because it raises the impression that the code is inefficient.
Is there a way to enforce (faster) redraw of the cached background graphics? What determines the delay before the screen content behind a control is restored?
Edit: as to the suggestion of setting DoubleBuffered=true: according to MSDN this should already be true by default. Indeed it doesn't make a difference if I set it true for the Label. On the other hand, setting it false introduces additional flickering as expected. In either case the restoration of the background remains delayed, like described above.
#Hans Passant: Thanks for telling us "When you move a control, its parent's OnPaintBackground() method needs to run to over-draw the pixels that were left behind by the control in its previous position."
For me the cp.ExStyle |= 0x02000000; // Turn on WS_EX_COMPOSITED did not work.
I am creating movable, Resizable Panel and when I moved it fast from left to right it was not displayed right "the half of the panel was often gone". I did this and now it works exactly like when I move a Windows Window.
This is in the MyPanel Class which I made and Inherits from Panel
protected override void OnMove(EventArgs e)
{
this.Parent.Invalidate();
base.OnMove(e);
}
So when I move the Movable panel with the mouse it wil Invalidate the "Parrent" in my case the Form and now it moves fine.
I'm trying to move the form instead of resizing it while I'm resizing if the right button is down.
Resize event:
if (rightMouseDown)
{
this.SetDesktopLocation(MousePosition.X - this.Width, MousePosition.Y - this.Height);
this.MaximumSize = new System.Drawing.Size(this.Width, this.Height);
this.MinimumSize = new System.Drawing.Size(this.Width, this.Height);
}
Global mouse event:
bool rightMouseDown;
private void HoldMouse(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Right && e.Clicks != 1)
{
rightMouseDown = true;
}
else if (e.Button == MouseButtons.Right)
{
rightMouseDown = false;
this.MaximumSize = new System.Drawing.Size(0, 0);
this.MinimumSize = new System.Drawing.Size(100, 100);
}
}
At the moment when I click the right button it freezes because the MaximumSize is constant, therefore I can't resize the form.
e.cancel would be awesome if it would work but I can't use that.
I'm able to capture the mouse events with a global one, the form events doesn't work weirdly.
I Got it working but only when the window's width is minimum and it goes to it's original width after the right mouse button goes up.
This is due to setting it to the default size. How can I keep the window in the changed size without setting it to MaximumSize 0,0?
First of all, I would suggest that you do not move the form while the right button is down, because this is highly non-standard and therefore likely to be perceived as highly peculiar by anyone trying to use your app. To be more specific, nobody is ever going to try either moving or resizing your form with the right mouse button, so:
if that's the only way you offer for moving your form, then nobody will ever be able to move your form.
if you also offer other ways of moving your form, then why bother with offering this way too?
Secondly, I would like to propose that this is most probably an X-Y problem meaning that you probably have some other issue, which you have told us nothing about, you think that you might address it by moving-by-right-click, then you discover that moving-by-right-click does not work for you, and you come here asking how to get moving-by-right-click to work. Why don't you begin by describing the real issue?
Thirdly, if you really want to proceed with moving your form by right-click, that's not how to do it.
First, you need to detect when the right mouse button is pressed. There are events for this. They work. If they don't work for you, that's not a reason to be doing other weird things instead. The statement "I'm not able to capture the mouse click with the Mouse events" is utterly bizarre, because a) it is a wrong use of the term "capture"; mouse capture is a very specific thing, (more about it later,) so please refrain from using it in other contexts, and b) if you cannot accomplish something, then that should be the subject of a stackoverflow question on its own. You cannot be trying utterly bizarre things because your attempts to do the right things failed.
So, once you have gotten detection of the right mouse click to work, then you need to set up mouse capture. (Look it up, search for "SetCapture".) That's what guarantees that you can keep receiving mouse move events, and finally a mouse-up event, even though the mouse has moved outside of your form while you were dragging it.
I'm currently working on a quite simple Windows Form program and I currently have a small issue regarding trackbars.
It's kind of a stats distributor for characters so I have 6 trackbars which should allow the user to distribute a set amount of point to each stats of the said character. They have a common maximum of points they can distribute so I check and confirm when they reach the max ammmount of points they could distribute but here's the problem, I don't know how to prevent the cursor to ONLY go up. I know I can disable the trackbars completely but then the user can't adjust the amounts of points even if he only wanted to lower a value to adjust it. How can I stop them from adding point without disabling the trackbars completely?
You can handle the ValueChanged event handler and do something like this:
int lastValue;
//ValueChanged event handler for your trackBar1
private void trackBar1_ValueChanged(object sender, EventArgs e){
if (trackBar1.Value < lastValue) trackBar1.Value = lastValue;
lastValue = trackBar1.Value;
}
I am trying to make it so that the user can scroll a richtextbox by clicking the window the richtexbox is on and dragging the mouse. Unfortunately I haven't gotten very far:
private void Main_PreviewMouseMove(object sender, MouseEventArgs e)
{
if (e.LeftButton == MouseButtonState.Pressed)
{
}
}
I've seen some suggestions on the web to track the last several x,y coordinates of the mouse and compare them to the x,y coordinates each time the mouse move event is triggered. Is there any less messy way to do this?
None that I know of. Unless you're using an API that handles it for you, you have to keep track of the information manually. And even if you did use an API just for mouse drags, it'd do the storing itself and likely just pass back the current X and Y, and the difference in X and Y, since the API wouldn't know what you want done with the information.
You'd be handling a little bit less information, but saving only about 5 lines or so of code to get the same result.
happy holidays!
i have a tablelayoutpanel (10x10). within each cell i have a picturebox which are disabled (enabled = false).
i am trapping mouse move over the table to catch mouse movement. here is the code:
private void tableLayoutPanelTest_MouseMove(object sender, MouseEventArgs e)
{
if (!placeShip)
{
c = tableLayoutPanelTest.GetControlFromPosition(homeLastPosition.Column, homeLastPosition.Row);
if (c.GetType() == typeof(PictureBox))
{
PictureBox hover = new PictureBox();
hover = (PictureBox)(c);
hover.Image = Properties.Resources.water;
}
Point p = tableLayoutPanelTest.PointToClient(Control.MousePosition);
Control picControl = tableLayoutPanelTest.GetChildAtPoint(p);
if (picControl != null)
{
TableLayoutPanelCellPosition me = tableLayoutPanelTest.GetCellPosition(picControl);
if (picControl.GetType() == typeof(PictureBox))
{
PictureBox thisLocation = new PictureBox();
thisLocation = (PictureBox)(picControl);
thisLocation.Image = Properties.Resources.scan;
homeLastPosition = me;
}
}
}
toolTipApp.SetToolTip(tableLayoutPanelTest, tableLayoutPanelTest.GetCellPosition(c).ToString());
}
when i run this the tooTipApp starts consuming upto 56% of the CPU. so there is something wrong.
also the picturebox image changing code stops working for some reason.
any help is very welcome!
thank you.
A few thoughts:
You're creating another PictureBox called hover - why? This code doesn't seem to do anything and it's almost certainly going to slow the loop down. I think you meant to just declare hover and cast it from c, but you're actually creating a new PictureBox instance and just throwing it away.
You're also never disposing of hover, as far as I can tell - so you end up allocating tons of memory and window handles. In general you should avoid creating new objects at all inside a MouseMove handler (small ones like hit tests are sometimes OK). As with the previous point - you probably didn't mean to write the new PictureBox().
You use PointToClient(Control.MousePosition) when the MouseMove event already gives you the control-specific mouse position (e.X and e.Y). This is costing you more time than it should.
Probably the most important, you're invoking SetToolTip on every MouseMove. You should only be invoking this when the tooltip has actually changed. You need to set a flag on which cell or control the tooltip was last displayed for, check for changes, then call SetToolTip.
You will get a lot of performance back if you avoid setting the tooltip text when it hasn't changed.
Other than that I want to echo the comment. This is a lot of processing for a mouse handler.
You should be trying to do an early test to see if the mouse is still over the same thing it was on the last move, and skipping most of the code in that case.