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How to intercept Enter key in AutoSuggestBox?

'Enter' key in AutoSuggestBox calls to QuerySubmitted event, like clicking the icon. It is a Windows 10 project.
I need to discriminate the Enter key because I use it to go to the next field. I tried KeyDown event, but it is not called.
How can I do it?

Don't ask me why, but you need to use KeyUp event and everything works fine.
Ex:
private void ContactsBox_KeyUp(object sender, KeyRoutedEventArgs e)
{
if (e.Key == Windows.System.VirtualKey.Enter)
{
//some stuff here
}
}

C# Keyboard button used to trigger a method

I'm writing a Hangman program in C# and when I press a keyboard button I want the button on the form to be clicked. Where should I write this? In form1.load()?

No, you should select the Form on which you want the event to be triggered, then go to the properties pane, select the event tab and go down to KeyPress event, double click it and add some code.
Normaly something like this would do what you want, just google the KeyChar value to determine the keyPress you want to control, you can add more if statements:
private void Form1_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == (char)13)
{
Button1.PerformClick();
}
//Other if statements if you want to keep an eye out for other keyPresses
}
[edit] I just remembered you might be also considering the shortcuts, in wich case the Button1.Text property should be marked &Button1, this way the "B" would be underlined and accept the alt+B shortcut to execute the button click event.
The & symbol is set before the letter you want for the shortcut, make sure you dont use the same letter for various buttons.

You wouldn't write the code in Form.Load() if you want it to happen in response to a keyboard event. That event occurs (and the code inside of it is executed) when your form first loads (appears on screen).
How about handling the KeyPress event and writing the code in that method, instead? Your form has one of those events, too.
Sample code:
private void Form1_KeyPress(object sender, KeyPressEventArgs e)
{
Button1.PerformClick();
}
The PerformClick method will generate a Click event for a Button control. You can handle that Click event in a similar way:
private void Button1_Click(object sender, EventArgs e)
{
// do something in response to the button being clicked
// ...
MessageBox.Show("Button clicked!");
}
If this event-handling stuff is confusing to you, make sure that you pick up a good book on programming in C# and/or the .NET Framework so that you learn it well. It's very important and not something to skip!

You have to enable KeyPreview property on the form, then you have to implements the KeyPress event directly on the form :
Form1.KeyPress +=new KeyPressEventHandler(Form1_KeyPress);
private void Form1_KeyPress(object sender, KeyPressEventArgs e) {
if(e.KeyCode == someKey) {
button1.performclick();
}
}

private void Form_KeyDown(object sender, KeyEventArgs e)
{
if(e.KeyCode == Keys.Left)
{
// Do your hang job
Button_Click(sender, EventArgs.Empty);
}
}

You need to subscribe to the events of interest and process them after. But before you need to read and study how to do that. It's a not a difficult issue in C#.
http://msdn.microsoft.com/en-us/library/ms171534.aspx
One time subscribed to the events create a function that you can call from button click and from keydown.

Should the TextBox raise the validating event when Return is clicked?

I'm a bit confused, as far as I remember the Textbox used to launch the Validating event when the used pushed the Enter key after entering the desired text but this is not happening now.
Do you know if this is the expected behavior or not?
Thanks.

see:Control.Validating Event
Note: If the CausesValidation property is set to false, the Validating and Validated events are suppressed.

I use a method similar to Javed Akram's answer, but instead of calling the Validating function, I just call focus on the parent...
private void TextBox_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == (char)Keys.Enter)
{
(sender as TextBox).Parent.Focus();
}
}
When the TextBox itself looses focus it will call its own Validating event

No not as far as I remember. The TextBox generally only validates when focus is gotten/lost unless something triggers it manually.
Hvae a look at Bolu's link for a list of validating triggers

Validating event is fired when the control lost its focus, so you can fire validating event yourself in keyPress event after checking, if the entered key is Enter key.
Sample Code:
private void someTextBox_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == (char)Keys.Enter)
{
someTextBox_Validating(sender, new CancelEventArgs());
}
}

Processing unprocessed enter key c#

I have to process enter (among other keys) on win form without it producing error sound, but only if the currently active control didn't process it already.
So, when enter is pressed while in a TextBox or DateTimePicker, i want to process it with a form (without error sound), but if it is pressed, for example, in DataGridView i want it to be handled the way DataGridView does by default.
OnKeyUp solves my problem with handling only unhandled keystrokes (e.Handled) and ProcessCmdKey (this) solves sound problem, but neither solves both.
Any suggestions?

Kudos for the very interesting question. Unfortunately, I can't seem to find a global event handler for all key presses other than overriding ProcessCmdKey on the main form per this article. Only issue with this method is that the arguments passed into the event handler delegate don't define what control is creating the event :(
So, my only thought is that you need to assign your event handler to every single control in the application. I've written some code that should help show you how to do this. I'm not sure what the adverse effects may be of assigning a KeyPress event handler to every control on your page though, but it's the only feasible solution I see.
Code:
private void Form1_Load(object sender, EventArgs e)
{
AssignHandler(this);
}
protected void HandleKeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == (char)Keys.Enter && (sender != this.textBoxToIgnore || sender ! this.gridViewToIgnore))
{
PlaySound(); // your error sound function
e.Handled = true;
}
}
public void AssignHandler(Control c)
{
c.KeyPress += new KeyPressEventHandler(HandleKeyPress);
foreach (Control child in c.Controls)
{
AssignHandler(child);
}
}

.NET: TextChanged event for TextBox not always firing, even though KeyUp and KeyDown are firing

I'm running into a very peculiar issue. I noticed that occasionally while typing into my TextBox, I'll lose some keystrokes. I added a bunch of trace statements in events hooked by this TextBox, and I found that when I lost keystrokes, the KeyUp, KeyDown, and KeyPress events all correctly fired, but the TextChanged event never fired.
Does anybody have any idea why this would happen? I could write this off as a ".NET bug", but I'd rather figure out if there is a solution here.
In case there is a suggestion that I use the KeyUp/KeyDown events to determine if the text has changed, there is an issue there as well. KeyUp/KeyDown are called multiple times for each key press, so it would be very difficult to determine if someone was typing the same letter multiple times.

Hmmm....
This is going to be a shot, but, you did say you have the KeyUp, KeyDown and KeyPress event handlers right? Have you set the flag e.Handled to true in the event handlers, have a look here:
private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
e.Handled = true;
}
private void textBox1_KeyUp(object sender, KeyEventArgs e)
{
e.Handled = true;
}
private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
e.Handled = true;
}
Have a look here in the MSDN about this Handled property. (If you have MSDN 2008 SP 1 installed locally, the link is ms-help://MS.MSDNQTR.v90.en/fxref_system.windows.forms/html/dfc80b44-1d79-6315-cbea-1388a048c018.htm)
To quote:
Handled is implemented differently by different controls within Windows Forms.
For controls like TextBox which subclass native Win32 controls, it is
interpreted to mean that the key message should not be passed to the underlying
native control.
If you set Handled to true on a TextBox, that control will not pass the key
press events to the underlying Win32 text box control, but it will still
display the characters that the user typed.
Maybe it is not set i.e. e.Handled = false; thereby preventing the TextChanged Event from firing?
Can you check and confirm this?
Edit: After dreadprivateryan's response, I can suspect (due to lack of code posted), based on his response, e.Handled is true for when Enter key is pressed and false for everything else which in my mind, thinks that is the reason why no further keystrokes are being accepted as a result of this.
Are you trying to set focus to another control upon the Enter key being pressed? It could be that both KeyUp and KeyDown are conflicting...
Remove the keyboard hook and disable it...
My suggestion is to change the code completely in this manner as shown, take out either KeyDown or KeyUp Event Handler as they, simplistically put it, are the same, ok, technically, it is designated respectively for when a key is pressed down, and likewise when a key is released. Have a look at this link here. There was a similar question posted here on SO.
In the example below, I used the keyUp event handler to switch focus to the next available control upon enter key being pressed. In the KeyPress event handler, this simply filters the input and only allows numbers 0-9 respectively, anything else gets discarded. Included in that event handler, is the allowance for the backspace key to provide editing.
private void textBox1_KeyUp(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter) SendKeys.Send("{TAB}");
}
private const string VALID_KEYS = "0123456789";
private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
if (VALID_KEYS.IndexOf(char.ToUpper(e.KeyChar)) != -1 || e.KeyChar == (char)8)
e.Handled = false;
else
e.Handled = true;
}
Hope this helps,
Best regards,
Tom.

I don't actually know, but I have a random guess: You running in a VM?
One hack you could use is make a timer that reads the text and compares to the previously entered value. Call the event handler code when it isn't equal to the previously checked value. When you need to use the final entered value, do one additional check, in case the timer hasn't fired yet.

Do you mean the keypress is actually lost and never shows up in the box? Or do you mean you don't get a TextChanged event for every keypress?
I believe the TextChanged event is driven by the operating system's EN_CHANGE notification which is sent via a WM_COMMAND message. I know that certain kinds of messages in Windows are "coalesced" to avoid redundant notifications. For example this can happen with WM_MOUSEMOVE messages and is why you don't receive a mouse move event for every pixel that the mouse moves across the screen.
I can't say for sure but I suspect that the TextChanged event behaves this way as well. I can say though that alternate input methods have this side effect too. When using a Tablet PC input panel, the textbox will not get a TextChanged notification for every character.