How to convert a character to key code?

Question

How can I convert backslash key ('\') to key code?

On my keyboard backslash code is 220, but the method below

(int)'\\'

returns me 92.

I need some generic conversion like

 int ConvertCharToKeyValue(char c)
 {
     // some code here...
 }

Any ideas?

Answer 1

You can P/Invoke VkKeyScan() to convert a typing key code back to a virtual key. Beware that the modifier key state is important, getting "|" requires holding down the shift key on my keyboard layout. Your function signature doesn't allow for this so I just made something up:

public static Keys ConvertCharToVirtualKey(char ch) {
    short vkey = VkKeyScan(ch);
    Keys retval = (Keys)(vkey & 0xff);
    int modifiers = vkey >> 8;

    if ((modifiers & 1) != 0) retval |= Keys.Shift;
    if ((modifiers & 2) != 0) retval |= Keys.Control;
    if ((modifiers & 4) != 0) retval |= Keys.Alt;

    return retval;
}

[System.Runtime.InteropServices.DllImport("user32.dll")]
private static extern short VkKeyScan(char ch);

Also beware of keyboard layouts that need to use dead keys (Alt+Gr) to generate typing keys. This kind of code is really best avoided.

Answer 2

If

var char = System.Windows.Forms.Keys.OemPipe; // 220
var code = (int)char;

then

public static int ToKeyValue(this char ch)
{
    return (int)(System.Windows.Forms.Keys)ch;
}