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Detecting multiple simultaneous key presses in C #

I want to mimic hyperterminal functionality for my serial communication in C # by detecting keystrokes of certain key combinations (escape sequences) that cannot be printed, such as Ctrl + C, Ctrl + Z, etc. I understand that these keys have their ASCII equivalents and can be passed as such. But I ran into problems with multiple keystrokes detection. Some of my codes are provided as a reference:

private void Transmitted_KeyDown(object sender, KeyEventArgs e)
{


   if (e.Modifiers == Keys.Control || e.Modifiers== Keys.Shift || e.Modifiers==Keys.Alt)
   {
       var test = (char)e.KeyValue; // Only able to detect a single keypress!


       ComPort.Write(test.ToString());

   }
}
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3 answers


If you are looking for regular keys, you can store them in a list: In KeyDown, add the key to the list. In Key Up, remove it from the list. In KeyDown, check what's on the list.

However, I'm not sure if there are keydown / keyup keys for modifier keys like ctrl, shift, alt. For them, you can do something like this:



bool CtrlDown = ((e.Modifiers & Keys.Control) > 0);
bool CtrlOnlyModifierDown = ((e.ModifierKeys & Keys.Control) == Keys.Control)
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e.KeyCode

contains information about the value of the key + modifier

e.KeyCode = e.KeyValue | e.Modifiers


Use e.KeyCode

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Not sure if you're in luck.

But try this code:

        switch (e.KeyData)
        {
            case Keys.Control:
                {
                    if (e.KeyData == Keys.Subtract) 
                    { }
                    else if (e.KeyData == Keys.C) 
                    { }
                    break;
                }
        }
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