CODEWITHSUNDEEP
c#.netwinapikeycode
Jeremy
Jeremy

Reputation: 46322

Convert character to virtual key code

I have a string of values, and I want to simulate key press events in a window for each character.

I plan on sending WM_KEYDOWN, WM_CHAR, and WM_KEYUP events to the window (as that is what seems to happen whan a key is manually pressed).

Those messages require an int be sent in the wParam based on a table of virtual key codes. I can loop through the string and get each character, but how do I take that character and convert it to a value that corresponds to the virtual key code? Convert.ToInt32() does not work.

Upvotes: 5

Views: 22382

Answers (7)

Andreas Magnusson
Andreas Magnusson

Reputation: 7434

VkKeyScanEx anyone? According to MSDN it:

"Translates a character to the corresponding virtual-key code and shift state."

(You could possibly also use VkKeyScan but beware that it has been superseded by VkKeyScanEx.)

Upvotes: 12

Hans Passant
Hans Passant

Reputation: 941237

Sending WM_KEYDOWN/UP is troublesome. The application itself already translates the WM_KEYDOWN message into WM_CHAR, using the state of the modifier keys (Shift, Alt, Ctrl) and the keyboard layout. Neither of which you can control, you'll get the wrong character, randomly.

Just send WM_CHAR messages, set the wparam to the character code. No need to worry about lparam, few apps ever use it.

Upvotes: 5

bobobobo
bobobobo

Reputation: 67224

The general solution is to use the SendMessage WinAPI function. This link describes SendMessage's signature and provides a sample import.

Oh and, to map VK codes you should use MapVirtualKey - its best to assume the mapping is arbitrary and not logical.

Upvotes: 0

Powerlord
Powerlord

Reputation: 88786

System.Windows.Forms.SendKeys is a WinForms class with static methods for simulating keyboard input on the active window.

The catch is that .NET has no way of focusing windows in another application (the SendKeys docs talk about how to get around that).

Upvotes: 0

Giorgi
Giorgi

Reputation: 30873

You can use Input Simulator library which provides a high level api for simulating key presses and handles all the low level stuff.

Upvotes: 0

Jerry Coffin
Jerry Coffin

Reputation: 490048

Generally speaking, instead of sending WM_KEYDOWN, WM_CHAR and WM_KEYUP messages directly, you should use SendInput (preferred) or possibly keybd_event (deprecated).

Upvotes: 0

Dominic K
Dominic K

Reputation: 7075

It looks like it takes the ASCII character and turns it into hex. For example, 'A' in hex is 41. According to your chart, A is 0x41, which is right (the 0x detonates hex).

Upvotes: 0

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