Select text inside textbox, ctrl+c and send to clipboard

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I have a textbox and I want to select the text inside, press Ctrl+C and copy the text in the clipboard.
I'm using this code here, but the thing is not doing it.
What can it be? Where's the mistake?
Thank you.

What I have tried:

C#

private void textBoxMovieName_KeyDown
                  (object sender, KeyEventArgs e)
{
    if (e.Control && e.KeyCode == Keys.C)
    {
        label6.Text = textBoxMovieName.SelectedText; //to preview the result
        //Clipboard.SetText(textBoxMovieName.SelectedText);
    }
}

Posted 29-Aug-23 17:08pm

_Q12_

Updated 13-Sep-23 6:36am

Deeksha Shenoy

v5

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2 solutions

Solution 2

Quote:
The last block of code :

C#
if (textBoxMovieName.SelectionLength > 0 && keyCode == (Keys.Control & Keys.C))
is not working correctly. If Im | instead of &&, it works when selection is >0 but whatever keypress. If I want to get the exact Ctrl+C from this line... is not working at all... any ideas?

Always start with the debugger: put a breakpoint on the line, and when it hits look at the value of keyCode. You will find that it doesn't match Keys.Control & Keys.C because & is a binary AND operation: Since Keys.<any key you can press> does not include the Keys.Control bitfield, the result will ALWAYS by zero. You need Keys.Control | Keys.C in order to match both.

Posted 29-Aug-23 18:50pm

OriginalGriff

Comments

_Q12_ 30-Aug-23 1:12am

Well, when I use | instead of &&, it will action C key weather I press or NOT the Control key. I specifically want it with Control+C and not just a simple C key.
I discovered that
if (keyCode == Keys.C)
{
label6.Text = textBoxMovieName.SelectedText;
}
will work for every C key press. All good on this side. But.. when I use this code:
if (keyCode == Keys.Control)
{
label6.Text = textBoxMovieName.SelectedText;
}
it is not working. Like you said, probably returning a 0. So practically when I tested this little last code, teoretically should have actioned when I press the Control Key ! And it did nothing. So the Control Key is the key to the solution !

_Q12_ 30-Aug-23 1:23am

I discovered that its another key for Control Key and is named ControlKey !
if (keyCode == (Keys.ControlKey & Keys.C))
{
label6.Text = textBoxMovieName.SelectedText;
}
So there are 2, Keys.Control and Keys.ControlKey - but none are working !

_Q12_ 30-Aug-23 1:30am

---
I tested with
if (keyCode == Keys.ControlKey)
{
label6.Text = textBoxMovieName.SelectedText;
}
So, this way, it fired when I press the Control Key
I also debug it as well.
but, it is still not working when is in this form:
if (keyCode == Keys.ControlKey & keyCode == Keys.C)

_Q12_ 30-Aug-23 1:55am

if (keyCode == Keys.ControlKey & keyCode == Keys.C) -doesnt work

OriginalGriff 30-Aug-23 1:58am

Read what I said: "You need Keys.Control | Keys.C in order to match both"
& is a binary AND operator: it only has 1 bits in locations where they are 1 in BOTH operands.

This is basic stuff - you should know all this long before you get to GUI code!

_Q12_ 30-Aug-23 2:05am

Ok then, I will use if (keyCode == Keys.ControlKey | keyCode == Keys.C)
as you say. But at the moment, if Im either pressing Control key OR C key, it is activating the if statement. How do I restrict it to only Control+C to activate the if statement?
Thank you.

OriginalGriff 30-Aug-23 2:49am

Are you being deliberately obtuse here?
Do I have to spell this out in words of one sylable?

OR together Keys.Control and Keys.C to form one side of the comparison with your keycode. If they match then the CTRL key is held down, and C has been pressed because binary OR sets bits if they are 1 in either or both or the two operands.

Seriously dude, you need to learn the basics before you get to "real stuff" or you will waste huge amounts of time guessing and hoping it works. Just like this: three hours and counting!

Dave Kreskowiak 30-Aug-23 8:19am

I can't believe I'm saying this, but "in his defense," the WM_KEYDOWN|UP messages don't include the state of the modifier keys. Yours was the first test code I tried and was reminded of that from WAY back in the day. You have to call GetKeyState for the modifiers.

Dave Kreskowiak 30-Aug-23 8:22am

I love how the code in the original question is not the code he's actually using, nowhere even close. What he actually is using drastically changed the answer.

_Q12_ 30-Aug-23 12:58pm

"Always start with the debugger: put a breakpoint on the line, and when it hits look at the value of keyCode."
I wish it was that easy. The code is running indefinitely in the sense that it is not stopping for me to have time to press a key from the keyboard. Thats the problem. In the moment I put a breakpoint in the code, it immediately jumps to that line ...when is inside this public bool PreFilterMessage(ref Message m) event that is, for my taste, very unusual and very different from the usual c# code. But I like unusual... I cant say I get it completely. I get something but not all. Now is clear it is over my ears. I was hoping I was making some evident mistakes but... it is some special formula/ special code I dont know and is relevant to this Pinvoke win32 or user32 unmanaged code way of thinking. Which I think is fascinating but... Im probably a code vampire at this point.
I look into http://pinvoke.net and all I find there, related to my problem, was user32 and not win32 as it requires after your advice. From what I can understand. I understand something, but not all.
WM_KEYDOWN and GetKeyState were others to search for but their results were too abstract to me.
Also, at debug time, I can see -some- values inside this event, but they appear to be random, numbers as 342212 or simple designators like "Shift"; I believe it was for that m.WParam .Like you clarified for me, it is over my ears. Im good, but not THAT good. Eh well, I tried.
By the way, the bigger picture here is that I was forced into this line of programming, because I am using a full screen windows media player and that by itself does not support keypress fuctions from standard C# environment. Only when is not in fullscreen. If I remember right. This is an old personal project and I can remember -some- important details about it.
Anyway, thanks for your support so far. I will find another way. I think this was a fascinating code experience and adventure, but when the woods get to thick...I give up. Vampires ! Hahahaha.

Dave Kreskowiak 30-Aug-23 14:23pm

User32, along with a ton of other Windows .DLLs you can import, is part of the Win32 API.

It does work.

        [DllImport("USER32.dll")]
        static extern short GetKeyState(int nVirtKey);

        private const UInt32 WM_KEYDOWN = 256;
        private const UInt32 WM_KEYUP = 257;
        private const int VK_CONTROL = 0x11;

        public Form1()
        {
            InitializeComponent();
            Application.AddMessageFilter(this);
        }

        bool IMessageFilter.PreFilterMessage(ref Message msg)
        {
            if (msg.Msg == WM_KEYUP)
            {
                Keys keyCode = (Keys)(int)msg.WParam & Keys.KeyCode;

                if (keyCode == Keys.C)
                {
                    if (GetKeyState(VK_CONTROL) != 0)
                    {
                        Debug.WriteLine("Ctrl-C was seen");
                    }
                }
            }

            return false;
        }

_Q12_ 30-Aug-23 16:57pm

[DllImport("kernel32.dll", SetLastError = true)]
static extern IntPtr LoadLibraryW(string lpLibFileName);
// [DllImport("USER32.dll")]
// static extern short GetKeyState(int nVirtKey);
the commented lines (your lines) throws me an error when compiling. Doesnt want to compile it.
So you must use the lines that are already working for me - the uncommented lines, the first 2.
Your line: if (GetKeyState(VK_CONTROL) != 0) is dependent of the static extern short GetKeyState(int nVirtKey); which in turn is dependend of the [DllImport("USER32.dll")].
So I can not use this code. Because all my other code is dependent by the first 2 uncommented lines.

_Q12_ 30-Aug-23 17:24pm

Error 1 Duplicate 'DllImport' attribute - when Im using it like this:
[DllImport("USER32.dll")]
[DllImport("kernel32.dll", SetLastError = true)]

_Q12_ 30-Aug-23 17:31pm

OK, I didnt do this thing for a very long time....
I managed to inject your code into mine, after all. youpii.
And indeed is working - so THANK YOU VERY MUCH !
the trick was, adding those head lines like this:

[DllImport("USER32.dll")]
static extern short GetKeyState(int nVirtKey);

[DllImport("kernel32.dll", SetLastError = true)]
static extern IntPtr LoadLibraryW(string lpLibFileName);
And after that, everything worked. Cool !!!

_Q12_ 30-Aug-23 17:35pm

Ive also followed your code back to the http://pinvoke.net and I find it there. Yah, you are good. I have to get used to this unmanaged code. I do it very rarely, and mostly with a hand from you guys here. So, my many thanks.

_Q12_ 30-Aug-23 19:03pm

-Small little problem...
this code: keyCode == Keys.C retains the value and when I select something else and press only the C key, (not ctrl+C), it will copy the selected text. When I press again Ctrl+C, it will behave correctly. When I press again Ctrl+C, only the C key, (not ctrl+C), it will copy the selected text and so on. So one time will remain as copy on C and another time on Ctrl+c. Is jumping from 1 to another.
I need, after 1 successful copy with ctrl+c, to clean (probably the) -keyCode- variable. I already looked for a set function in pinvoke.com and is nothing there to reset this variable.
I made a couple of lines, by myself, but none worked, voila:
if (keyCode == Keys.C)
{
if (GetKeyState(VK_CONTROL) != 0)
{
label6.Text = textBoxMovieName.SelectedText;
//Clipboard.SetText(textBoxMovieName.SelectedText);
keyCode = Keys.None; GetKeyState(0); //reset the variable
m.Msg = (int)WM_KEYUP;
}
}

Dave Kreskowiak 30-Aug-23 23:12pm

I have no idea because, again, nobody can your code.

You're just guessing that it's "holding onto values", when it's impossible for that code to do that.

It works fine for me as I published it.

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Dave Kreskowiak · Accepted Answer · 2023-08-29T17:46:00

Solution 1

You don't have to do anything. Copying to the clipboard is already supported by the textbox without doing anything at all.

The code you have will already show the selected text in your label and the TextBox will already copy that text to the clipboard.

The code you posted works, so this is a problem somewhere else.

Posted 29-Aug-23 17:46pm

Dave Kreskowiak

Comments

_Q12_ 30-Aug-23 0:06am

Heh, my bad, somewhere in the code I had this borrowed that took priority.

#region FullScreenKeyboard
//This is win32 plumbing
// 'Can only set the full screen mode when the video is playing >> else 'Catastrophic Error'
private const UInt32 WM_KEYDOWN = 256;
private const UInt32 WM_KEYUP = 257;
public bool PreFilterMessage(ref Message m)
{
if (isSearchActivated == false)
{
Keys keyCode = (Keys)(int)m.WParam & Keys.KeyCode;

#region WM_KEYUP
if (m.Msg == WM_KEYUP)
{
if (keyCode == Keys.Right)
{
player.Ctlcontrols.currentPosition += 5;
}
if (keyCode == Keys.Left)
{
player.Ctlcontrols.currentPosition -= 5;
}
if (textBoxMovieName.SelectionLength > 0 && keyCode == (Keys.Control & Keys.C))
{
label6.Text = textBoxMovieName.SelectedText;
}
return true;
}
#endregion
The last block of code :
if (textBoxMovieName.SelectionLength > 0 && keyCode == (Keys.Control & Keys.C))
is not working correctly. If Im | instead of &&, it works when selection is >0 but whatever keypress. If I want to get the exact Ctrl+C from this line... is not working at all... any ideas?
Thank you.

Dave Kreskowiak 30-Aug-23 0:42am

The debugger would have told you what's going on. The value of keycode is NOT going to be (Keys.Control & Keys.C). It's just going to be Keys.C. You have to check for the Control key being held down separately with a call to the Win32 function GetKeyState(VK_CONTROL).

You can find the information you need to import that function on PInvoke.net.

_Q12_ 30-Aug-23 0:54am

See if you can find something for me, because this is not really my cup of tea. I used this code because otherwise it wouldnt work, so I got forced to use it. I also got help on it. See if you can find that PInvoke call to Control key. I will search for it as well, but you have better chances than me.

Dave Kreskowiak 30-Aug-23 8:09am

You better make it your cup of tea because I'm not your research assistant, and this skill is a REQUIREMENT to do this job! I told you which site to go to and which function name to search for. If you can't do that very simple thing, hang up your keyboard/mouse and walk away.

Andre Oosthuizen 30-Aug-23 5:02am

Quote: See if you can find something for me, because this is not really my cup of tea - ROFL. Another Dracula in the making...

Dave Kreskowiak 30-Aug-23 8:15am

I believe the correct term is "assistive nosferatu".

Andre Oosthuizen 30-Aug-23 8:27am

LOL