Detecting if ASCII Control Characters are pressed (C#)

[Recursive]

I am seeking a method to detect if ASCII Control Characters are pressed. My code currently shown here is not working too well i suspect.

 
private void Transmitted_KeyDown(object sender, KeyEventArgs e)
{
          if (e.Modifiers==Keys.Control)
           {
               test = (char)e.KeyCode;              
           }
}
 

[tlhintoq]

"ASCII control characters" such as an ASCII 05 "Enquiry", or an ASCII 23 "End of transmission block" ??

How would someone type one of these?

[Recursive]

ASCII 05 is Ctrl+E and ASCII 23 is Ctrl+W as seen from http://nemesis.lonestar.org/referenc...des/ascii.html.

I would like to find a more elegant way to do this rather than manually defining each block like this :

if (e.KeyData == (Keys.Control | Keys.A))
            {
                test = (char)01;
 
 
            }
 
            if (e.KeyData == (Keys.Control | Keys.B))
            {
                test = (char)02;
 
 
            }
 
 
            if (e.KeyData == (Keys.Control | Keys.C))
            {
                test = (char)03;
 
 
            }
 

[tlhintoq]

How do you feel about this logic? (suedo code, you can flush out)

On keypress

if control key pressed
{
switch e.KeyData
{
Case E
...
Case W
...
Case R
...
}
else
{
// No control key so we don't care
}
}

[GaryTexmo]

Out of curiosity, do you need this globally (from outside the application), or just inside the particular control?

[Recursive]

Not exactly what I was looking for. I would prefer grabbing the KeyCode of the keypress and then putting it in a char.

[Recursive]

@GaryTexmo
Just inside the particular control (textbox).

[GaryTexmo]

I tried a google search and came up with this...
http://www.java2s.com/Code/CSharp/Ev...Keypressed.htm

You don't need to worry about the ASync method in there. The particular lines of code that should interest you are...

        lbl.Text = "Key Down: " + e.KeyValue.ToString();
        lbl.Text += "\nKey Code: " + e.KeyCode.ToString();
        lbl.Text += "\nKey Data: " + e.KeyData.ToString();

... which would be in your KeyDown event.

Does that help any?

[Recursive]

@GaryTexmo
Not exactly, I already know about key modifiers, codes , values and such. The challenge is simplifying my existing code and enhancing it to include all keyboard modifiers.

[GaryTexmo]

Like what? I tried that little demo program on the site and it was trapping ctrl-e, which is one of the things you wanted.

Oooh, you mean you want the actual ascii value of it? I see... well that changes everything :D Sorry for the confusion.

I'm at a loss here. I tried a few console programs in C# and QBasic and I was able to get the functionality you want by reading the input stream, but I can't figure out how to do it on a form. I even tried some code I had that would read a global input stream that used all sorts of dllimports thinking maybe there was something in there, but it returns the same as the event arguments.

At this point, I think I agree with Thlintoq's method. While it's not exactly what you wanted, it will give you what you're looking for.

[guimel]

It looks like the KeyValue of the event is the Ascii value of the key (in uppercase), thus the following works:

if (e.Modifiers == Keys.Control && e.KeyValue >='A' && e.KeyValue <='Z')
    int test = e.KeyValue - 'A' + 1;
 

Be aware that this relies on undefined behaviour as it's never specified what the KeyValue of a specific key is.

Edit:
To make it a bit safer, you could have:

    int test = e.KeyValue - (int)Keys.A + 1;
 

That's guaranted to work as long as the values of Keys.A to Keys.Z are all consecutive and in the right order in the Keys enum.