According to this question, the answer begins with "The MouseEnter/Leave events are too unreliable to do this." What exactly makes these events unreliable?
The mouse position is only polled every so often. It's very possible that one of those events - the mouse entering, or leaving, could occur between when the polls occur, and the events would not fire correctly.
This also makes a pretty concrete assumption that mouse movement will be continuous, rather than discrete - what if the user has a touch screen monitor? What if the mouse goes directly from inside the control to being way outside it, with no movement in between?
You missed the point entirely. These events are unreliable for the OP question, not in general.
The question was about seeing if the cursor is inside the forms client area. Having many controls the MouseEnter/Leave are unreliable because you will get these events even if you are inside the form's area.
Related
On System.Windows.UIElement there is a CaptureMouse() and a paired ReleaseMouseCapture() method. In this WPF DragDrop sample they call CaptureMouse on MouseDown and release it on MouseUp. The documentation in MSDN is about as useless as it comes - "CaptureMouse -> Captures the mouse."
In my head before trying it I assumed that it somehow locked the mouse inside the UIElement bounds, but that's clearly not the case when I try it. From experimenting, it seems to have something to do with responding to events when the mouse is outside of the UIElement, but not wanting to be a cargo cult programmer I don't want to just use it because the example does, I'd like an authoritative description of what it means.
From Capture and Uncapture the Mouse on MSDN:
When an object captures the mouse, all mouse related events are treated as if the object with mouse capture perform the event, even if the mouse pointer is over another object.
Only the capturing control receives the mouse events until released.
Capturing the mouse is useful for dragging because all the dragging code can exist in the one control, rather than being spread over multiple controls.
When it has captured the mouse, a control will receive mouse events even if the mouse pointer is no longer within its bounding area.
Typically, it's used for:
Drag and drop
Buttons (to handle Mouse Up when you put the mouse down on the button and move the mouse before you release the button)
The Silverlight 2 documentation for it has a more verbose description, I don't know why it isn't a part of the 3.5 documentation page too:
When an object has captured the mouse, that object receives mouse input whether or not the mouse pointer is within its bounding area. The mouse is typically only captured during simulated drag operations.
...
It works the same with WPF, and so the reason it is used with DragDrop, is that is how the
it knows to report back to the control being dragged from when the mouse may be outside of that control. If you comment out the MyCanvas.Capture() and the Capture(Null) (which clears it) then you can no longer drop.
I have the following event handler for a NotifyIcon within a WPF application using Forms integration:
void MyNotifyIcon_MouseDown(Object sender, System.Windows.Forms.MouseEventArgs e)
{
ShowSettingsWindow();
}
However, e.Location = {X=0,Y=0} always. Is there a way to make this work?
Update
Oddly enough, people have voted to close this question and have downvoted it. However, its clearly not working and simple enough to create a new NotifyIcon inside of a WPF application's App.xaml.cs file and try it out for yourselves.
Update
As Hans pointed out, this is by design. It still doesn't answer the question of what possible workarounds are. Furthermore, this is a bad design, because:
This event occurs on a MouseDown, which means it should have some context of the mouse position when it was clicked in order for it to have occurred. The WmMouseDown handler for NotifyIcon does have the ref Message m property which other controls use to establish the correct position, however it seems to disregard this property and not use it in the event handler. I'd call this a major bug.
Since its post-mortem, getting the Cursor.Position inside of MouseDown will not give you the exact last location in which the MouseDown was raised after the tray icon is clicked. There is a small delay between you clicking it, and it raising the event in which you can further move the mouse. You can test this out yourself with an application that gets the mouse coordinates by quickly moving the mouse after clicking the tray and getting its location within the MouseDown handler. A workaround (which answers my question) would be to save the last location on every MouseMove using Cursor.Position instead and using this last location on MouseDown as the location that clicked the icon. All of which spells out a clear need for the mouse location of when the event actually occurred.
Apparently, I am the only one who cares about these inconsistencies in .NET while a lot of people seem to tolerate them or not understand their implications properly.
Its not ideal because the framework is designed to not send proper mouse event arguments as Hans pointed out, but one workaround is to save the last location on every MouseMove using Cursor.Position and using this last location on MouseDown as the location that contextually clicked the icon.
Have you considered setting a global mouse hook? It would bypass the typical WPF event model, and you would have to manually determine coordinates. This may involve additional API calls.
Details can be found in this post Global mouse event handler
I have some straight WPF 3.5 controls handling left mouse clicks that I need to use within a Surface app (SDK 1.0). The problem I am facing is that do not work by default. I am thinking of wrapping each control in a SurfaceContentControl and translating ContactTouchDown or ContactTapGesture events to corresponding MouseDown events.
The problem boils down to - how to "inject" or simulate arbitrary routed mouse events? I have tried InputManager.Current.ProcessInput() but didn't get very far. Any help is appreciated.
Try to use AutomationPeer classes. For example ButtonAutomationPeer is for Button. The code below initiates a click.
ButtonAutomationPeer peer = new ButtonAutomationPeer(button);
IInvokeProvider provider = (IInvokeProvider)peer.GetPattern(PatternInterface.Invoke);
provider.Invoke();
evpo's idea is an interesting one (though if you're working with custom controls, they rarely come with AutomationPeer classes).
You can't simply 'inject' mouse input by sending WM_MOUSE* events to your app... WPF would indeed process the message but when it goes to figure out the position of mouse for that event, it will query the actual mouse API instead of trying what you stick in the WM.
So really all you can do is tell windows to move the actual mouse cursor and act as though the button is being clicked/released. Some code you can use for that is in http://www.codeproject.com/KB/system/globalmousekeyboardlib.aspx
That said, while you can technically do this, it sucks... you've got an expensive multitouch device but are 1) showing a mouse cursor on it 2) limiting arbitrary parts of it to being used 'single touch' (and only one of those arbitrary parts at a time and 3) coming up with an arbitrary method of determining which finger you will treat as the mouse-controlling one
Hallo,
I am trying to keep track of the mouse position and also its delta position. Is there any nicer way of doing this then implementing all the mouse events for all my forms in my window?
The problem with using the MouseMove event is that as soon as the mouse moves outside of the form it stops working properly. Implementing the mouseEnter, mouseLeave improves it somewhat, but it does still not feel perfect. Any ideas?
Regards,
You have to handle lower level windows events.
Check out this example: http://www.codeproject.com/KB/cs/globalhook.aspx
I have an application wich open a modal form with the ShowDialog method.
Once this form is displayed I want to capture the mouse movement even if the cursor is outside the form.
How can I capture the mouse movement? I saw something with the Capture property but I cannot manage to make it work.
[edit]
I want to be notified if the mouse move outside the form.
The Capture property is the correct way, but there are some limitations.
Only the foreground window can capture the mouse
Mouse capturing can be disabled by other parts of the system
The Win32 API function SetCapture gets reset everytime a "mouse up" event occours. I assume that also applies for .NET.
See the remarks section of Capture property.
When the mouse is captured, you'll receive the usual events but with a wider mouse coordinate range (for example a negative X position, if the mouse is left of the capturing control)
Mouse capturing is fragile, because of it's global nature. Check if there are other ways to handle certain events. Perhaps the MouseLeave or MouseEnter events are enough in your case.
You can just use the static property Control.MousePosition.
You can read the position of the cursor, using the Cursor.Position property, see Cursor.Position