Capturing Ctrl + Shift + P key stroke in a C# Windows Forms application

Question

Possible Duplicate:
Capture combination key event in a Windows Forms application

I need to perform a particular operation when (Ctrl + Shift + P) keys are pressed.

How can I capture this in my C# application?

Best way to do it: http://stackoverflow.com/questions/400113/best-way-to-implement-keyboard-shortcuts-in-winforms/400325#400325 — Hans Passant, Oct 04 '11 at 16:47
Do you want any Ctrl+Shift+P key combination to perform the operation regardless of which application has focus? Or do you simply want a "global shortcut" for this operation in your own application? That answer will determine which of the below answers is best; the P/Invoke answer is better if you want to "grab" the keys from another app using a taskbar app or service, while a KeyDown handler is preferred for in-app keyboard shortcuts. — KeithS, Oct 04 '11 at 17:50

score 25 · Accepted Answer · answered Oct 04 '11 at 16:26

25

Personally I think this is the simplest way.

    private void Form1_KeyDown(object sender, KeyEventArgs e)
    {
        if (e.Control && e.Shift && e.KeyCode == Keys.P)
        {
            MessageBox.Show("Hello");
        }
    }

answered Oct 04 '11 at 16:26

Matt

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Yes this will capture keydown from form n... if you place a usercontrol on form and try to do the same...handler won't get fired – Gaddigesh Oct 10 '11 at 13:46
3

It will ,if you set the form's KeyPreview property to true. – JCCyC Dec 12 '14 at 15:14
1

Its really worked for me. Please add this note for everyone that we have to set the Forms-> keypreview - > True. – Abhilash Thomas Nov 23 '16 at 12:22

score 4 · Answer 2 · edited Feb 07 '13 at 14:37

The following is not only a way to capture keystroke on your form, but it is in fact a way to add global Windows shortcuts.

1. Import needed libraries at the top of your class:

// DLL libraries used to manage hotkeys
[DllImport("user32.dll")] public static extern bool RegisterHotKey(IntPtr hWnd, int id, int fsModifiers, int vlc);
[DllImport("user32.dll")] public static extern bool UnregisterHotKey(IntPtr hWnd, int id);

2. Add a field in your Windows Forms class that will be a reference for the hotkey in your code:

const int MYACTION_HOTKEY_ID = 1;

3. Register the hotkey (in the constructor of your Windows Forms for instance):

// Modifier keys codes: Alt = 1, Ctrl = 2, Shift = 4, Win = 8
// Compute the addition of each combination of the keys you want to be pressed
// ALT+CTRL = 1 + 2 = 3 , CTRL+SHIFT = 2 + 4 = 6...
RegisterHotKey(this.Handle, MYACTION_HOTKEY_ID, 6, (int)'P');

4. Handle the typed keys by adding the following method in your Windows Forms class:

protected override void WndProc(ref Message m) {
    if (m.Msg == 0x0312 && m.WParam.ToInt32() == MYACTION_HOTKEY_ID) {
        // My hotkey has been typed

        // Do what you want here
        // ...
    }
    base.WndProc(ref m);
}

Still relevant and works today in 2020. Thanks. – vr_driver Aug 19 '20 at 12:51 — vr_driver, Aug 19 '20 at 12:51

score 2 · Answer 3 · edited Feb 07 '13 at 14:35

2

You can use the KeyDownEvent with a lambda event handler:

Here is some more information about KeyDown. Read the article and think about the scope in which you want to have this behavior.

this.KeyDown += (object sender, KeyEventArgs e) =>
{
    if (e.Control && e.Shift && e.KeyCode == Keys.P)
    {
        MessageBox.Show("pressed");
    }
};

edited Feb 07 '13 at 14:35

Peter Mortensen

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answered Oct 04 '11 at 16:24

fixagon

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score 0 · Answer 4 · edited Feb 07 '13 at 14:34

0

Use the GetKeyboardState API via P/Invoke. It returns an array representing the state of each virtual key recognised by Windows. If I'm not mistaken, you can cast the Keys enum to a byte and use it as an index as follows:

byte[] keys = new byte[256];
GetKeyboardState(keys);
bool isCtrlPressed = (keys[(byte)Keys.ControlKey] == 1);

-

Resources:

P/Invoke definition
MSDN documentation: GetKeyboardState function

edited Feb 07 '13 at 14:34

Peter Mortensen

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answered Oct 04 '11 at 16:22

Polynomial

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Oops, screwed up the code. It should be: bool isCtrlPressed = (keys[(byte)Keys.ControlKey] == 1); – Polynomial Oct 04 '11 at 16:23
is it that complicated? There should be simpler way in c# – Gaddigesh Oct 04 '11 at 16:38
@Poly: You can edit your post. – Otiel Oct 04 '11 at 16:42

Capturing Ctrl + Shift + P key stroke in a C# Windows Forms application

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