So I want to make a Key_Down and Key_Up event in C#, so that they execute no matter what is selected/tabbed to. Basically I want to make a global key event. Is there a way I can do this? Am I supposed to put it on a form? Because if so, then my comp has a problem.
You need to make the form KeyPreview property set to true. It Gets or sets a value indicating whether the form will receive key events before the event is passed to the control that has focus.
When KeyPreview property is set to true, the form will receive all KeyPress, KeyDown, and KeyUp events. After the form's event handlers have completed processing the keystroke, the keystroke is then assigned to the control with focus.
You can read more about Form.KeyPreview Property
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I've got a winform application. In the application I have a Panel with multiple Buttons.
Now when the Buttons don't have the Focus I can capture the keypressed Events in the form itself. But when the Buttons have the Focus the form (even if the Buttons don't catch the Event explecitely) only they get the keypressed Event and not the form.
Now my question is: Is there any way to centralize the keypressed behaviour (without creating a keypressed Event for each and every button and call a central method with that Event)?
In essence only 1 method needs to be defined with the appropriate Parameters:
Example:
private void Event_Key_Press_Check(object sender, KeyPressEventArgs e)
This method then only Needs to be put in as the Name of the method used in the Event (form designer), or added as the Event.
That way only 1 method is used.
Thus there is no shorter way and the Event Needs to be defined for every single button (instead of 1 central Event that is always triggered).
Set form property KeyPreview to true and set KeyPress handler. Then form will handle this event before buttons.
See KeyPreview MSDN documentation.
I've had the same issue, and it was pretty easy to resolve :)
Check here : KeyPress at form level with controls
Just set the KeyPreview property (of your form) to True. This way your form will handle KeyPress event before any other control, even if one of them has the focus
A key is pressed while starting up a winform program. I'd like to read this keyboard input during program startup process. How can I do that?
Set KeyPreview of your Form to True and add your code in form's KeyPress or KeyDown event.
I have a bug in my application that I don't know how to how to attack. Basically, key events "go missing" after some time. I have added event handlers to KeyDown, KeyPressed and KeyUp that write to the console (both for the Form and one of its TextBoxes). Here's the correct order of things:
control_PreviewKeyDown
ShellForm_KeyDown
control_KeyDown
ShellForm_KeyPress
control_KeyPress
ShellForm_KeyUp
control_KeyUp
In the failed state (which I can't reproduce consistently), I get these events when pressing a key (TextBox has focus):
ShellForm_KeyUp
control_KeyUp
Form.KeyPreview is true.
It's the same for all TextBoxes in the Form; they are not disabled and not set to readonly, but it's no longer possible to write text.
Problem is, I don't really know where to begin.
Begin with Application.AddMessageFilter(...) just to intercept the flow of events.
You can find some ideas here.
I am working with a TextBox, and need to fire some logic when the textbox has lost focus.
My problem is twofold:
The Leave event is firing on every keypress for some reason, meaning the logic is run with every keypress when it should not.
When using the Focused property of the Textbox as a double-check, simply exiting out if the property is still set, it now works when the user uses the mouse to leave, but not when the user tabs out.
The Focused property of the TextBox in question is False as of when its Leave event fires when the mouse is used to change focus, but it is still True when the Leave event fires due to a Tab keypress. Seriously?
I need a workaround, because the logic firing on every keystroke is causing a problem for users right now that needs to be fixed post-haste.
I created a form with a textbox on it and attached event handler to the leave event of that text box. I then typed a bunch of stuff into said textbox. The event was not raised. I hit tab, the event was raised. I then clicked back in the textbox, typed some more, and then clicked another control and the event was raised.
I'm just saying that something else is interfering with the textbox. I would look into that a little more, or post some code demonstrating the problem.
How can I capture the Keydown event of a form that is not active?
I found references to ProcessKeyDown but I couldn't find any help on that.
Please set KeyPreview of the form to true. First select form and press f4 key, it will open property window and their is KeyPreview and set it to true.
Right cilck on the form and cilck properties, then there will be flash button , it is for events for that object. Find thier Keypress event. just doulbe click on the column corresponding to that event. It will create event for keypress.
For the documentation and help, check this link.
Keypress events are only sent to Controls that have input focus. You can use the Control.HasFocus property to determine whether your Control has focus or not. Use the Control.Focus() method to give your control focus.
You can set a low level keyboard hook using SetWindowsHookEx() to listen for key press events.
If what you want to do is trigger some code in your program upon keys being pressed in the operating system regarding of whether the form is active or not then you can use the method described in this article:
Processing Global Mouse and Keyboard Hooks in C#
Here is a simple example of a program using that library to simulate a virtual mouse by pressing the numeric keys on the numpad.
'1'-'4' and '6'-'9' are directional keys, '5' is left click, '0' is double click.
Program.cs
Form1.cs
Observe that i didn't call the Application.Run(); with a new Form1() parameter so that the application would run but will not be visible on screen. To end the program you have to press CTRL+SHIFT+ESC, go to Processes page and end the process manually.