as a part of my WinForms application, I want to move a picturebox (blue box) onto the grid as seen below.
I'm moving the picturebox according to the mouse positions (while the left mouse button is pressed down).
Now my problem is, that when dragging the picturebox over the grid, the MouseEnter event is supposed to be called (each box in the grid is a picturebox in itself, with the event attached to it). The event gets called when simply moving with the mouse over it, but as soon as I'm dragging the blue box over it, it doesn't.
So my question is, is it possible that the picturebox on top (blue box) blocks the MouseEnter event of the picturebox on the bottom from firing? And if so, is there a way to work around it? I've thought about using Drag&Drop, but this seemed as the easier solution.
Thanks in advance.
Related
I have a PictureBox control on my form for which I have written two events for MouseEnter and MouseLeave. On MouseEnter anther PictureBox enters the form and stands beside the original and with MouseLeave the second PictureBox goes way.
All works fine. Except when the cursor is on the original PictureBox’s border area the MouseEnter and MouseLeave events are repeatedly run. So the second image enters and leaves the form until the cursor is taken away. This makes a strange sight.
How can I avoid this situation?
The border area can be tricky, especially when you want to trigger something the might influence it even if it is only by a few pixels..
One classic situation is when you want to resize or move a control by clicking an dragging it at its border. Unless you use the internal calls and simply code mouseenter, -leave, -move, -down and -up you may well end up with e.g. moving the control away from the mouse and thereby triggering another leave event.
This often occurs only at one set of borders, like left&top or right&bottom.
You need to check you code for any such influences, like the new PictureBox pushing the old one away by a few pixels or a resize that makes it smaller; even one pixel can lead to the effect you see..
If the MouseEnter event is triggering a border to be drawn, or the size of the first PictureBox to change in any way, that can cause the effect you describe.
You could add a check against the mouse coordinates in MouseEnter to ensure that the mouse pointer gets far enough into the control's interior before the event fires. That would prevent an instant firing of the Leave event.
I am having an issue with MouseLeftButtonUp not firing when I press my left mouse button down on one UIElement (i.e. a Rectangle) then move my mouse to another Rectangle and release the left mouse button.
According to this page http://msdn.microsoft.com/en-us/library/system.windows.uielement.mouseleftbuttonup.aspx it is because the event only fires when on the same element that the left mouse button was pressed down on,
Occurs when the left mouse button is released while the mouse pointer is over this element.
How can this problem be solved?
I tried adding a Grid element beneath both Rectangles to handle the MouseLeftButtonUp event and that didn't seem to solve the problem. When moving from Rect to Rect it doesn't fire, but when moving from Rect to Grid it fires. When moving from Grid to Rect it doesn't fire either. Different bubbling strategy?
Here is what I'm working with. Examine the second column where each Rectangle is YELLOW. They have been 'highlighted' by pressing on the top rectangle and dragging down to the bottom Rectangle. Once reaching the bottom rectangle I would like to be able to have the mouse button up event occur (by any means) to perform some action.. doesn't work!
If this seems like a weird solution to this type of 'highlight' mechanic or flat-out misuse of Rectangle in this situation don't be shy to say so, I'm new to WP8.
Consider adding a Grid over all the rectangles, that way you would get MouseButtonUp (as long as the mouse was released on the grid), but you would have to calculate which rectangle was moved over based on the MouseEventArgs.GetPosition.
You might also want to look into UIElement.CaptureMouse(), .ReleaseMouseCapture(). Capturing mouse means that the MouseButtonUp will be fired even when the mouse moves away from the MouseButtonDown-Rectangle, but the MouseMove and MouseButtonUp will be raised for the Capturing Rectangle (so you would still have to calculate the rectangles to highlight), until it calls ReleaseMouseCapture().
I've created a form that's maximized over the entire screen.
Within that form, and sized to fill the entire form, I've placed a panel with background color set to Red. The form's TransparencyKey is set to Red.
Therefore, the Panel is like a "keyhole" - you can see the desktop that's directly underneath it.
When the user clicks on the panel, OR, presses a key on the keyboard, I want to take action.
But, because the panel is completely transparent, when it is clicked or a key is pressed, nothing happens. If I make the panel non-transparent (setting it's background color to Blue, for example), it does respond to clicks.
What's the best way to get the panel to respond to clicks and keypresses?
Do I have to hook all mouse an keyboard events on the entire system or is there a simpler way?
The panel does not take in text input, you can set your main form to handle the keypress event.
this.KeyPress += new System.Windows.Forms.KeyPressEventHandler(this.form_KeyPress);
http://screensnapr.com/v/VovWAi.png
As for getting the mouse location on your panel, you can use the mouseclick event
this.panel1.MouseClick += new System.Windows.Forms.MouseEventHandler(this.panel1_MouseClick);
http://screensnapr.com/v/DB3kCQ.png
I have tested it, and it works on a fullsize transparent panel
I've discovered that I can use GetAsyncKeyState to respond to both keypresses and mouse clicks.
[DllImport("user32.dll")]
public static extern int GetAsyncKeyState(System.Windows.Forms.Keys vKey);
Then, I can call GetAsyncKeyState(Keys.LButton) and GetAsyncKeyState(Keys.Escape), for example. Much simpler than hooking all keyboard and mouse events.
Here is the problem:
I have a simple c# form
I have a simple c# user control containing a picturebox and other button.
My form contains one instance of the user control.
I want that when the user do a mouseEnter in the picture box, the mouse cursor change and when the user do a mouseLeave of the picturebox, the mouse go back to normal.
What is happening now is that the events are not fired at all. I put break point into MouseOver, MouseEnter, MouseMove, MouseLeave, etc and none of thems fired. It's the first time I have this problem in C#.
I think it has something to do with the "routed event" but I can't figure it out. If there is another way to achieve what I'm doing, this will also be considered a solution. What is important is that at the end, the user control will be the master of the mouse cursor over his "territory".
Thanks in advance!
What events are you using? The UserController.MouseEnter and UserController.MouseLeave events or the PictureBox.MouseEnter and PictureBox.MouseLeave events?
You should use the latter as the PictureBox will handle the event if the mouse enters the user controller directly through the PictureBox.
As InBetween wrote, PictureBox.MouseXXX should be firing. You can trap those in your UserControl.
If you want the event to be fired on behalf of UserControl, just disable the PictureBox. Be aware though that the event would fire for any mouse position over the UserContrl, not only the PictureBox.
It is not easy to explain the problem without an image and without code. For those interested, I have made a sample C#/WPF project that can be downloaded from http://rapidshare.com/files/461745095/02.WPFControlEvents.rar
It is a very small project (45KB). The problem is as follows (with my apologies for the contorted description):
A "fancy" (and rather ugly) button contains a stackpanel which in turn contains 1.) a label, 2.) a canvas, 3.) two (2) concentric ellipses, all laid out from left to right.
There is a MouseEnter and a MouseLeave event handler for the stackpanel which displays a message in the title bar indicating whether the mouse is over the stackpanel or outside of it.
The problem is: when the mouse is over the label (in turn contained in the stackpanel), the mouse is (correctly) reported as being over the stackpanel. When the mouse is moved over the canvas (which is also contained in the stackpanel), the mouse is (incorrectly?) reported as not being over the stackpanel, yet when the mouse is moved a little further to the right (over the two ellipses, which are on the canvas), the mouse is reported to be over the stackpanel again.
Why is it that when the mouse is over the canvas it is reported as not being over the stackpanel but when the mouse is over the ellipses (which are painted on the canvas) it is reported as being on the stackpanel ?.
thank you for shedding light into the problem,
John.
Chances are you need to set the Background of the Canvas to Transparent. This will allow it to be "hit testable" and report mouse over events.
More info can be found here, but Canvas has a null background by default.