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C# custom ENTER key behaviour

I have a small projet in which I want several buttons to behave differently when Clicked or Ctrl+Clicked. To achieve that, each of those buttons has this kind of function attached to their Click() event :
private void Button1_Click(object sender, EventArgs e)
{
int value = 10 //default value
bool boool = false;
if (ModifierKeys == Keys.Control)
{
using (var form = new NUP_Popup(0, value, value, "maximum ?"))
{ //creates a simple window that allows user to change the value of 'value'
form.ShowDialog();
if (form.DialogResult == DialogResult.OK)
{
value = form.retVal;
boool = true;
}
else return;
}
}
//do stuff here, either with default or user value
}
Now, Clicking or Ctrl+Clicking behaves as intended with this function. My problem is that this behaviour doesn't apply when my buttons are activated using the Enter key : Enter key alone triggers the "normal" behaviour but Ctrl+Enter does nothing (button is not activated).
I already have overriden the ProcessDialogKey() function to close the window when Escape is pressed, so I thought I could use it to make Enter key presses trigger the Click() event function :
protected override bool ProcessDialogKey(Keys keyData) //Allows quit when Esc is pressed
{
if (Form.ModifierKeys == Keys.None && keyData == Keys.Escape)
{
this.Close();
return true;
}
if (keyData == Keys.Return)
{
this.OnClick(new EventArgs());
}
return base.ProcessDialogKey(keyData);
}
And that's where I'm stuck. Of course this doesn't do anything but I don't really have an idea of what to type inside my second condition to make it work.
Maybe I'm using the wrong approach ? Can someone point me in the right direction to do it ?

Assuming you placed a Label with ID Label1 and a button with ID Button1, following will do:
private void button1_Click(object sender, EventArgs e)
{
label1.Text = "Button Clicked";
if (Control.ModifierKeys == Keys.Control) label1.Text += " with Ctrl";
}
private void button1_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == '\n') button1_Click(sender, new EventArgs());
}
to your solution, simply add a KeyPress event to your Button1 and apply following code inside the keypress event Button1_KeyPress:
if (e.KeyChar == '\n') Button1_Click(sender, new EventArgs());

Okay, so I finally found a working solution by adding this to my overriden ProcessDialogKey() method :
if (keyData == (Keys.Enter | Keys.Control))
{
(this.ActiveControl as Button).PerformClick();
}
I don't know if it qualifies as "clean" code, but it has the merit of fulfilling my 2 requirements : making Ctrl+Enter function as Ctrl+Click without having to declare 2 methods per Button.

I found a solution that enables you to either click Enter or Ctrl+Enter:
private void txtIP_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == '\n' || e.KeyChar == '\r') btnStart_Click(sender, new EventArgs());
}

MaskedTextBox detecting a tab

I have a MaskedTextBox that formats text to look like (###) ###-####
After entering the first 3 digits, they like to press "TAB" to the next set. Unfortunately by pressing TAB, they are in the next field.
So my boss asked me to modify the application so that the users remain in the same field but the cursor is in the next group.
private void maskedTextBoxHomePhone_KeyPress(object sender, KeyPressEventArgs e)
{
MaskedTextBox mtb = (MaskedTextBox)sender;
if (e.KeyChar == (char)Keys.Tab)
{
if (mtb.TextLength == 3)
{
mtb.SelectionStart = 4;
}
}
}
I've also tried
private void maskedTextBoxHomePhone_KeyDown(object sender, KeyEventArgs e)
{
MaskedTextBox mtb = (MaskedTextBox)sender;
if (e.KeyCode == Keys.Tab)
{
if (mtb.TextLength == 3)
{
mtb.SelectionStart = 4;
}
}
}

Tabs have a special meaning, that will cause the focus to change, so the event handler won't get called.
You could work around this by using the Leave event of a text box and counting the textlength that you have stored in some local variable:
private void maskedTextBoxHomePhone_Leave(object sender, EventArgs e)
{
if (_mtbTextLength == 3) { //change selection start and goes back to masked text box }
}
Anyway, actually I would try to convince my boss otherwise. Do you
really need this? Tabs are always used to change fields, you can get
your users confused.
Another option would be to change the Tab behaviour by overriding the ProcessCmdKey:
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
if (keyData == Keys.Tab)
{
//Do something
}
}

Tab will not fire keydown or keypress event

I am working in a webform and have a form with a tab bar on it. Each tab has multiple text boxes in it. I have the tab indexes incremented, starting with 1 for each tab. I want to tab from tab to tab if the user hits the end of the form and hits tab.
I used the leave method and changed the tabs for my tab control the only problem is if I didn't hit tab and say I click to another control on that tab it will still shoot over to the new tab.
I figure a way to solve this would be to listen for the tab key press and if the key press is tab on leave then change the form to the other tab, I just can't seem to get it to work though. I have tried with keypress and keydown but neither will pick up that tab as a key. If I was to say click or hit start typing it will trigger the events but tab will not.
Any suggestions?
I have tried these and none of these event would even trigger.
private void afsiTxtDaysForTempOEpriceOverrides_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == 11)
{
afsiTxtDaysForTempOEpriceOverrides_Leave(sender, e);
}
}
private void afsiTxtDaysForTempOEpriceOverrides_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == "11")
{
afsiTxtDaysForTempOEpriceOverrides_Leave(sender, e);
}
}
private void afsiChkSalesBaseCostUpdate_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == 11)
{
afsiChkSalesBaseCostUpdate_Leave(sender, e);
}
}
private void afsiChkSalesBaseCostUpdate_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == 11)
{
afsiChkSalesBaseCostUpdate_Leave(sender, e);
}
}
EDIT: Found out that the page is using UltraWinTabControl from Infragistics so maybe this is causing some issues with the tabbing.

I ended up needing to override ProcessCmdKey now I face a new problem that is kind of related but not particular to this so I will add it as a comment if I get my answer.
private bool isTab = false;
private bool isShiftTab = false;
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
if (keyData == Keys.Tab)
{
isTab = true;
ShiftTab.Append("Tab");
}
else
{
isTab = false;
}
return base.ProcessCmdKey(ref msg, keyData);
}

You will need to have the MultiLine property set to true, and AcceptsTab also set to true.

Or use e.KeyCode instead or e.KeyData, it worked for me
if (e.KeyCode == Keys.Tab | e.KeyData == Keys.Enter)

KeyUp event firing from next control

I've 5 buttons in my windows application. When I click arrow keys the focus changing between buttons, then only
KeyUp
event firing. How to stop this?

Subscribe to the PreviewKeyDown event instead.
Occurs before the KeyDown event when a key is pressed while focus is on this control.
As you move through the buttons, the sender parameter will contain the previously selected button.
I found a solution that should work for you, adapted from here. Apparently, MS made the decision that the arrow keys wouldn't trigger the KeyDown event, so you can't cancel them.
One workaround is to specify that your arrow keys are normal input keys, like any other key. Then the KeyDown event will fire and you can cancel the button press if you want.
private void button1_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
{
if (e.KeyCode == Keys.Left || e.KeyCode == Keys.Right || e.KeyCode == Keys.Up || e.KeyCode == Keys.Down)
e.IsInputKey = true;
}
private void button1_KeyDown(object sender, KeyEventArgs e)
{
e.Handled = true;
}
You may want to read the other answers and comments in that post to see what would work best in your situation.

Answer for your question in comment
void button1_LostFocus(object sender, EventArgs e)
{
button1.Focus();
}

To prevent Up from moving focus from a Button you have to utilize at least 3 methods:
bool _focus;
private void button1_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
{
if (e.KeyCode == Keys.Up)
_focus = true;
}
private void button1_KeyUp(object sender, KeyEventArgs e)
{
_focus = false;
}
private void button1_Leave(object sender, EventArgs e)
{
if(_focus)
button1.Focus(); // or (sender as Control)
}
Trick is to use flag when user press Up and to return focus in Leave. You have to unflag in KeyUp, otherwise it would be impossible to change focus (by pressing Tab to example).
You could possible unflag in Leave, I didn't test it.

Catching Ctrl + C in a textbox

Despite me working with C# (Windows Forms) for years, I'm having a brain fail moment, and can't for the life of me figure out how to catch a user typing Ctrl + C into a textbox.
My application is basically a terminal application, and I want Ctrl + C to send a (byte)3 to a serial port, rather than be the shortcut for Copy to Clipboard.
I've set the shortcuts enabled property to false on the textbox. Yet when the user hits Ctrl + C, the keypress event doesn't fire.
If I catch keydown, the event fires when the user presses Ctrl (that is, before they hit the C key).
It's probably something stupidly simple that I'm missing.

Go ahead and use the KeyDown event, but in that event check for both Ctrl and C, like so:
if (e.Control && e.KeyCode == Keys.C) {
//...
e.SuppressKeyPress = true;
}
Also, to prevent processing the keystroke by the underlying TextBox, set the SuppressKeyPress property to true as shown.

Key events occur in the following order:
KeyDown
KeyPress
KeyUp
The KeyPress event is not raised by noncharacter keys; however, the noncharacter keys do raise the KeyDown and KeyUp events.
Control is a noncharacter key.
You can check with this line of code:
if (e.KeyData == (Keys.Control | Keys.C))

I had a problem catching Ctrl + C on a TextBox by KeyDown. I only got Control key when both Control and C were pressed. The solution was using PreviewKeyDown:
private void OnLoad()
{
textBox.PreviewKeyDown += OnPreviewKeyDown;
textBox.KeyDown += OnKeyDown;
}
private void OnPreviewKeyDown( object sender, PreviewKeyDownEventArgs e)
{
if (e.Control)
{
e.IsInputKey = true;
}
}
private void OnKeyDown( object sender, KeyEventArgs e)
{
if (e.Control && e.KeyCode == Keys.C) {
textBox.Copy();
}
}

D'oh! Just figured it out. Out of the three possible events, the one I haven't tried is the one I needed! The KeyUp event is the important one:
private void txtConsole_KeyUp(object sender, KeyEventArgs e)
{
if (e.KeyData == (Keys.C | Keys.Control))
{
_consolePort.Write(new byte[] { 3 }, 0, 1);
e.Handled = true;
}
}

If you want to catch such combinations of keys in KeyPress Event look at this table here:
http://www.physics.udel.edu/~watson/scen103/ascii.html
in Non-Printing Characters section you can see the Dec numbers for each combination.
For example, Dec number for Ctrl + C is 3. So you can catch it in KeyPress Event like this:
private void btnTarget_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar != 3) // if it is not Ctrl + C
{
// do something
}
}

Try the following: capture the up arrow and down arrow events. When you detect down arrow for CTRL, set a flag; when you detect up arrow, reset the flag. If you detect the C key while the flag is set, you have Ctrl+C.
Edit. Ouch... Jay's answer is definitely better. :-)

I don't know if it's because some change in newer version or because I am trying to use this on ListBox, but there is no e.Control in KeyEventArgs e that I get from KeyDown.
I had to work around solution, I came up with this (it's not the prettiest one, but it works fine):
private List<Key> KeyBuff = new List<Key>();
private void ListBox_KeyDown(object sender, KeyEventArgs e)
{
if (!KeyBuff.Exists(k => k == e.Key))
KeyBuff.Add(e.Key);
if (KeyBuff.Exists(k => k == Key.LeftCtrl || k == Key.RightCtrl) &&
KeyBuff.Exists(k => k == Key.C))
{
// Desired detection
Clipboard.SetText(SelectedText);
}
}
private void ListBox_KeyUp(object sender, KeyEventArgs e)
{
KeyBuff.Clear();
}

For me, it's not working with KeyDown event so I tried with PreviewKeyDown and it's worked.
private void txt_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
{
if (e.Control == true && e.KeyCode == Keys.C)
{
Clipboard.SetText(txt.SelectedText);
}
}