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I read somewhere that the Alt Gr key found on some layouts is a substitute for Ctrl + Alt.
However, what can this combination be used for? Are there any documented shortcuts using Ctrl + Alt?
Sparx
Posted 2010-12-09T09:57:45.673
Reputation: 1 667
27
IBM named this key "alternate graphic" and it's not a substitute for CTRL + ALT, though CTRL + ALT was implemented as a substitute for ALT GR in Windows. It is a key modifier (like CTRL or SHIFT) that enables a different input than is normally expected of a key.
Depending on your keyboard and location setup, it can be used to produce characters with diacritical marks when used in conjunction with alphabetic keys (most often vowels), and the third symbol that is printed on some keys, for example, € (ALT GR + 4) or ¦ (ALT GR + `) that appear on my UK keyboard. Continental European keyboards generally have many more keys with extra symbols printed on them which correspond letters with the various types of diacritical marks used in those languages.
See AltGr key for more information.
James
Posted 2010-12-09T09:57:45.673
Reputation: 1 171
@JürgenA.Erhard: I thought the same too. – Alex Essilfie – 2015-01-28T20:56:23.177
3Nice pointing out that Alt Gr is implemented as Ctrl+Alt but Ctrl+Alt does not map to Alt Gr. – Alex Essilfie – 2015-01-28T21:09:12.993
In India, in some designated keyboards, the key Alt Gr + 4 gives the Indian currency symbol (₹) – Code Poet – 2016-07-29T16:34:09.220
I always thought it stood for Alt Green, as I remember the key was printed with green letters on the IBM PC/AT keyboard, but just saying Alt. It's strange that the Wikipedia article does not even mention that. – paradroid – 2010-12-09T14:20:21.273
1I, for a long time, thought it meant "Alt German"... – Jürgen A. Erhard – 2010-12-09T15:23:08.373
9
For some keyboards, it allows some alternate combinations. In some keyboards it allows the cent symbol or the euro symbol - Wikipedia has a pretty comprehensive list of combinations using Alt Gr.
However using a US/Windows keymap, it doesn't do anything in most cases.
Journeyman Geek
Posted 2010-12-09T09:57:45.673
Reputation: 119 122
Even some US layouts have a <€> somewhere on them (on <5> in my case). – Ignacio Vazquez-Abrams – 2010-12-09T11:48:42.923
mine is a british keyboard set to american ;p. it has the euro symbol on the 4 if it were on british keysets – Journeyman Geek – 2010-12-09T16:12:09.047
4
Also, handy for people with accessibility needs who have to do a Ctrl+alt+del. You try it one-handed.
Bonus
Posted 2010-12-09T09:57:45.673
Reputation: 1 192
I doubt that works? – Arjan – 2010-12-09T15:12:14.190
@Arjan It doesn't work. – AndrejaKo – 2010-12-09T15:19:41.507
1Does on every keyboard I've used. Maybe it's a UK-keymap thing. – Bonus – 2010-12-09T15:22:38.530
@Bonus Never worked for me on any keyboard I used, even on UK keymap. Maybe there's some not so obvious setting that controls that? – AndrejaKo – 2010-12-09T15:24:18.463
Wouldn't that defeat the purpose of the secure attention key if this was enabled without any specific setting, like @Andreja wonders about?
– Arjan – 2010-12-09T16:17:15.8471@Arjan Maybe some keyboards produce different scancode for AltGr? Could it be that of some keyboards AltGr is actually configured to behave as ctrl+alt? – AndrejaKo – 2010-12-09T16:48:01.387
2The C+A+D sequence is handled at a much lower level than the AltGr to Ctrl+Alt conversion (at least on Windows and Linux), so they are not going to work exactly the same. (Except perhaps in the case of a keyboard sending Ctrl+Alt scancodes.) – user1686 – 2010-12-09T19:20:01.777
4
Alt gr is necessary for some languages like Polish:
Alt Gr + a = ą
Alt Gr + s = ś
Alt Gr + shift + n = Ń
Antyradek
Posted 2010-12-09T09:57:45.673
Reputation: 41
Such keyboard layout can lead to interesting bugs and issues. Read The curious case of the disappearing Polish S.
– Kamil Maciorowski – 2017-07-03T09:19:38.6401
I am pretty sure it is implemented like this.
You can test the vkCode from the KBDLLHOOKSTRUCT to see what you get.
Mapped enum list from here, here, and www.pinvoke.net/default.aspx/Constants/WM.html
It should be equivalent to this:
using System.Windows.Forms;
isAltGr ? (Keys) (1 << 19) : Keys.None
private static Keys BuildKeyData(Keys virtualKeyCode) => virtualKeyCode | (IsDownControl ? Keys.Control : Keys.None) | (IsDownShift ? Keys.Shift : Keys.None) | (IsDownAlt ? Keys.Alt : Keys.None) | (IsAltGr ? (Keys) (1 << 19) : Keys.None);
private static bool IsDownControl => IsKeyPressed((ushort)VirtualKeys.LeftControl) || IsKeyPressed((ushort)VirtualKeys.RightControl);
private static bool IsDownShift => IsKeyPressed((ushort)VirtualKeys.LeftShift) || IsKeyPressed((ushort)VirtualKeys.RightShift);
private static bool IsDownAlt => IsKeyPressed((ushort)VirtualKeys.LeftMenu) || IsKeyPressed((ushort)VirtualKeys.RightMenu) || IsKeyPressed((ushort)VirtualKeys.Menu);
private static bool IsAltGr => IsDownControl && IsDownAlt;
Latency
Posted 2010-12-09T09:57:45.673
Reputation: 11
0
Important Alt+Gr key combinations on a default German keyboard are:
Mike L.
Posted 2010-12-09T09:57:45.673
Reputation: 4 539
3Ctrl + Alt + Delete – Joe Taylor – 2010-12-09T12:41:14.847