C# certainly isn't my strong suit so I appreciate all the generous folk sharing their knowledge. I'm working with a Windows Form and I've read up on events and have found some excellent help on how to modify a TabControl so I can have an OnDraw event that will add some coloring to the tabs.
The color of each tab is based upon the state of a connection variable:
Current (green)
Lost (red)
Stale (yellow)
The OnDraw event works excellent for updating the color of each tab, but that only occurs when the user selects a different tab to view.
What I would like to happen is for the color of each tab to be updated whenever the connection state changes. For example, let's say Tab#1 is colored green, but then the connection state changes to stale so now the tab needs to be colored yellow but it won't get colored like that until the user clicks on a different tab and the OnDraw event is triggered.
So I'm trying to figure out how to do that. When the OnDraw event is triggered normally (by the user clicking on a different tab) a "DrawItemEventArgs" parameter is passed into the even handler. That variable is already populated with the pertinent data needed to figure out which tab was clicked on, the boundaries of that tab and etc. So I am unsure where it came from or how I can programmatically re-create such a call to re-color the tabs whenever the connection variable changes.
Please let me know if I need to clarify anything!
Thank you.
You can call Invalidate() on the control to force a repaint.
If you have an event fired when your connection state changes you could do an
InvalidateVisual()
on all of your tabs from within that event.
If you want to have a constant refresh going, then you probably need to create System.Timers.Timer object.
Once you create a Timer and set the timer tick value to whatever interval you need (in milliseconds) it will fire the OnTimerTick event at regular intervals. From this event you can trigger a call to your OnDraw method through the Invalidate() method. Invalidate tells the system that your screen needs to be refreshed and it will call OnDraw and OnPaint at the next available opportunity.
Related
I want to be able to hold down a button (i.e. MouseLeftButtonDown) and have it's event repeat fire.
I code Mouse.Capture(button) in the MouseLeftButtonDown event and Mouse.Capture(null) in MouseLeftButtonUp event.
If I hold the mouse button down, the MouseLeftButtonDown only fires once. I can see this not by setting a breakpoint but by using Console.Writeline().
I had this very code working at some point. Then I refactored and put the mouse events in an Interface. Everything still works except this repeat action now!
Update - More information:
Here is the before call which was in a specific class:
Mouse.Capture(sender as MenuGelButton)
MenuGelButton is a xaml creation of ellipses and text to make a cool button.
Since adding the interface (which is common code for several xaml creations all of which inherit the interface), here is the current call from within the interface:
Mouse.Capture(sender as UIElement)
Update of Update:
A mouse click event is not designed to auto repeat fire. A keyboard event is. I had this working (and it continues to work) on a keyboard event not the mouse event. Sorry for the confusion...
I believe you are looking for Microsoft's RepeatButton. You can use it in XAML just like you would use a Button, and it fires a click event multiple times.
From their documentation:
A RepeatButton is a button that raises Click events repeatedly from the time it is pressed until it is released. Set the Delay property to specify the time that the RepeatButton waits after it is pressed before it starts repeating the click action. Set the Interval property to specify the time between repetitions of the click action. Times for both properties are specified in milliseconds.
Try doing something like this:
mouse button --> fires event
in the event, set a timer of your liking (how many times per second would you like the action to happen?)
in a loop, every time timer fires, check to see if mouse button is still "down". If yes, fire. If not, don't fire.
you'll probably want to add another event of mouse button up, that will stop the timer, so it won't fire anymore (or bind to a bool that will let you know if you want to fire ... up to you ..)
Hope it helps.
I'm implementing a module which needs to handle both MouseClick and MouseDoubleClick on a ChartControl of DevExpress. The version that I'm using is v12.2.
When I double click on that chart, both events are fired. I'd like (and I think that it must be) it just fires one event, in this case, MouseDoubleClick.
So, anyone know how to fix that problem?
What's I've tried:
Handle MouseClick or Click event and see MouseEventArgs#Clicks property. But it's always 1.
What's I'm using:
Declare a boolean variable to tell if MouseDoubleClick is fired. On MouseClick handling, just waiting for a moment, then do the codes if that variable does not turn on. I think this is a bad implementation.
You need a time machine to see the difference between the two. Inevitably a double-click starts with a single click, you always see the first click first.
You can get a time machine that sees the future by using a timer that delays the past. Set its interval to SystemInformation.DoubleClickTime + 16 and start it in the Click event, stop it in the DoubleClick event. If the Tick event fires then it was a single click.
That works, but do note that the delayed response to a single click is fairly annoying. Best not to annoy your user with a user interface like that.
I would like to remove the original event behavior of controls within a form (similar to design mode).
So, when the user clicks on the button, i only want to capture that event. I do not want the original button event to be fired. Is this somehow possible?
I am looking for a generic solution. So it should work with any form and any control within the form.
Reason: I wrote a form validation rules designer. It uses reflection to enumerate all form-types in the entry assembly. The user can then select a form type, the designer creates that form, enumerates the controls, and embedds the form in the designer panel.
clicking on a control, opens a formular designer panel, and the user can now create a formular for that control and saves the formular to a DB.
When the form is then opened in the normal "runtime" mode, it loads its validation formulars.
Events are not in fact disabled in the Winforms designer. The designer executes the constructor of the form through Reflection, everything in the InitializeComponent() method executes, including the event subscriptions. Wherever this might cause a problem, the controls check the DesignMode property (prevents a Timer from starting for example) or by custom designers. The form is displayed underneath a transparent layered window on top of which the selection rectangle and drag handles are painted. Which prevents issues with mouse clicks and keyboard focus.
You probably ought to look at this magazine article to get this working for you.
From what I understand from your question, I guess, you can still use the "DesignMode" property for this as well. In your event handling routine, you may want to bypass execution by checking on this property:
if (this.DesignMode) return;
as the first statement in your event handling block of code.
Let's say I have a created a Form class and a CustomControl class.
On my Form I have two instances of the CustomControl, and a Panel.
Panel has 4 event handlers: MouseEnter (to give a different cursor), MouseLeave (to reset the cursor), MouseDown (to start the dragging thread), and MouseUp (to kill the dragging thread and do post-drag logic).
I can drag the Panel onto the CustomControl. When I do this, the code in Form detects what I have done and deletes Panel from Form.Controls, passes some meta-information to CustomControl, which then creates a Panel on itself.
Basically, it is a hand-over. The Panel object now belongs to the CustomControl.
(This is necessary. It's complicated to explain why, but imagine the custom control has something like scrollbars, and it's necessary for the Panel to belong to the CustomControl so that it will scroll with the CustomControl.)
Now, when I click down on the Panel in the CustomControl, the Panel's MouseDown is triggered, it gets deleted from CustomControl.Controls and sends some meta-information back to the Parent (the Form), which then re-creates the Panel as it was at the start - however already in a dragging state so that the user can re-position the Panel onto the second CustomControl, or perhaps put it back onto the Form. The function which creates the Panel when the Form is first initialised is exactly the same function which creates it now.
However, the Panel's MouseDown has not been triggered. The mouse is down, but the event is not firing because the mouse was already down when it was created. So, I manually call the MouseDown handler in the function in Form which accepts the meta-information from CustomControl.
Unfortunately, this only half-works. The MouseUp handler isn't firing. I can pick up the Panel off the CustomControl and drag it around on the Form as expected, but when I release the mouse, the Panel is stuck to the cursor.
I'm not really sure how to get around this?
An ideal solution would be for, when the meta-information is passed back to Form and the new Panel is created, the MouseDown event to somehow fire naturally as though the user had just clicked down on the Panel.
It sounds like you are creating a new instance of Panel when you move it from CustomControl to Form and back and loosing it's state.
You should either try to pass the actual instance owned by Form to CustomControl without creating a new one or you could capture the state of the Panel in another object which you can pass to the constructor when you create a new Panel so that it is in the same state as the one you were dragging?
It seems as though you are trying to manually fire mouse events to compensate for problems in your design.
Always better to give some example code if you can than lengthy textual explanations.
Look at this
Instant of custom control is disappear when click outside it
I have problem like you.
you shouldn't use a local variable for handling mouseEvent.
Try to use "Capture" function. It's work for me.
I am writing an app where the user should be able to alter the action of a button.
The user should right-click a button, and choose an option from a pop-up context menu. Once the choice has been made the button will perform a different action when the user uses a normal click.
I've already gotten the "Click" event working for a normal button click, however the "MouseClick" event handler isn't working correctly.
The "MouseClick" event gets activated on regular left-clicks, but never get's called for right-click.
Is there some default event handling being performed that is ignoring that right-click?
I'm sorry to say that this would be a serious UI blooper. Perhaps it would make more sense to add a small combobox next to the button.
Perhaps something like this?
http://www.codeproject.com/KB/buttons/SplitButton.aspx
If you want to display a context menu with actions to choose from it should be enough to assign a ContextMenuStrip to the ContextMenuStrip property. There is usually no need to manually handle the mouse events for that.
surely it would be better to implement it on the MouseDown event rather than the MouseUp event. i dont understand how this is much different from MouseClick event
edit: Just tried this and it works a treat :)
In Button (and certain other controls), the MouseClick event is only fired for the left button. Refer to MSDN.
If you want to know about the right button, respond to the MouseUp event--though as other posters have pointed out, this isn't a great UI idiom.
Use the Mouse UP event... test that Button.X and Button.Y are within the size of the button otherwise you have moved the mouse away from the button.
Terry G