Unable to capture Enter Key - c#

I have a simple form by which I take input:
12 Buttons, 1 Textbox (disabled & read-only)
this is what I do to handle input
Login_KeyDown() is common method I call for all the KeyDown of every UI component & the form itself..
private void Login_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Escape)
{
Application.Exit();
}
else if (e.KeyCode == Keys.NumPad9 || e.KeyCode == Keys.D9)
{
button3.BackgroundImage = Properties.Resources.button_hover;
button3.ForeColor = Color.White;
pin.Text = pin.Text + "9";
}
else if (e.KeyCode == Keys.Back)
{
button11.BackgroundImage = Properties.Resources.button_hover;
button11.ForeColor = Color.White;
if (pin.Text.Length > 0)
pin.Text = pin.Text.Substring(0, pin.Text.Length - 1);
}
else if (e.KeyCode == Keys.Enter)
{
MessageBox.Show(pin.Text);
}
}
This code works fine when I start the app but after I have clicked on any component, rest of the code works fine but "Enter Key Condition" doesn't work.
My guess is as "Enter Key Condition" is not working for UI components or something like that.
I have also tried using "Key Press Event" which uses KeyPressEventArgs then checking KeyChar == 13 but that is also not working.
What is the problem, and how can I solve it?
p.s.
I have not set any button click events for any button, the app is 100% KBoard based.

Check out PreviewKeyDown. Return raises that event on button controls.
private void Form1_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
{
if (e.KeyCode == Keys.Return)
MessageBox.Show("I found return");
}
Or alternatively you can force it to raise those special keys in the KeyDown Event by using:
private void Form1_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
{
if (e.KeyCode == Keys.Return)
e.IsInputKey = true;
}
More information: http://msdn.microsoft.com/en-us/library/system.windows.forms.control.previewkeydown.aspx

Have you tried to use
Keys.Return
Instead
Edit:
Just thought of this. Do you have the acceptbutton set for the main form?

This is because your Form has AcceptButton defined. For example, you have a "OK", "Accept" or "Confirm" button with DialogResult set to "OK". This tells its parent form that there is an AcceptButton, and the Enter event on the form would go to this button.
What you should do is to catch the Enter key at form level. Add this code to the form:
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
if ((this.ActiveControl == myTextBox) && (keyData == Keys.Return))
{
//do something
return true;
}
else
{
return base.ProcessCmdKey(ref msg, keyData);
}
}

Related

How to prevent call several KeyDown events by pressing a single key on the keyboard?

I have set KeyPreview property of the form to true in order to call keyboard events of the form before control events.
Both the form and the control in the form have KeyDown event like:
form:
private void Form1_KeyDown(object sender, KeyEventArgs e)
{
if (e.Control && (e.KeyCode == Keys.Enter || e.KeyCode == Keys.Return)) {
MessageBox.Show("Control + Enter (Form)");
}
}
control:
private void TextBox1_KeyDown(object sender, KeyEventArgs e)
{
if (!e.Control && (e.KeyCode == Keys.Enter || e.KeyCode == Keys.Return)) {
MessageBox.Show("Control + Enter (TextBox)");
}
}
As you see the difference between these two parts of code is that in the form event code I need to call the KeyDown event when the user presses CTRL and Enter keys at the same time,
In the TextBox event code, I need to call the event when the user presses Enter key without holding CTRL-key.
The problem is that when I press Ctrl and Enter keys at the same time both of the above events will call.
How to prevent call both events?
I suggest you use the textBox1_KeyUp event. You can refer to the following code. My test was successful.
public Form1()
{
InitializeComponent();
this.KeyPreview = true;
}
private void Form1_KeyDown(object sender, KeyEventArgs e)
{
if (e.Control && (e.KeyCode == Keys.Enter || e.KeyCode == Keys.Return))
{
MessageBox.Show("Control + Enter (Form)");
}
}
private void textBox1_KeyUp(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Control)
{
e.Handled = true;
}
else if (e.KeyCode == Keys.Enter)
{
MessageBox.Show("Control + Enter (TextBox)");
}
}
Use the ProcessCmdKey and like this.
protected override bool ProcessCmdKey(ref Message msg, System.Windows.Forms.Keys keyData)
{
int WM_ALRT_DOWN = 0x0104;
int WM_KEYDOWN = 0x0100;
if (msg.Msg == WM_ALRT_DOWN && (int)msg.WParam == (int)Keys.F4) //Alt + F4
{
return true; // The key is manually processed
}
if (msg.Msg == WM_KEYDOWN && (int)msg.WParam == (int)Keys.Escape) //Esc
{
return true; // The key is manually processed
}
if (msg.Msg == WM_KEYDOWN && (int)msg.WParam == (int)Keys.Space) //Space
{
return true; // The key is manually processed
}
}

If Enter key hit - show message. Else - type as normal

If the user hits the enter key, I want to show a message saying the enter key was hit. Else, I want to type in the textbox as normal.
private void enterCheck(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
MessageBox.Show("Enter Was Clicked");
}
}
If enter is hit the message is displayed correctly. However, if I try to type a sentence, nothing appears in the textbox.
This will work...
private void enterCheck(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
MessageBox.Show("Enter Was Clicked");
}
else
{
MessageBox.Show(e.KeyCode.ToString());
}
}
However I don't want a messagebox showing every letter that was typed.
Try this:
private void enterCheck(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
MessageBox.Show(e.KeyCode.ToString());
}
else
{
e.Handled = true;
}
}
Please work! This is the most confusing I've ever encountered!
Use the KeyPress event:
// This event occurs after the KeyDown event and can be used to prevent
// characters from entering the control.
private void textBox1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
{
// Check for the flag being set in the KeyDown event.
if (e.KeyChar == (char)Keys.Return)
{
// Stop the character from being entered into the control since it is non-numerical.
MessageBox.Show("Enter Was Pressed");
e.Handled = true;
}
}

if (e.KeyCode == Keys.Enter) is non-functional

I have this
private void toolStripTextBox1_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == (char)Keys.Enter || e.KeyChar == (char)Keys.Return)
{
var items = new[] { 500+ objects here };
if (toolStripTextBox1.Text.StartsWith("www."))
{
webBrowser1.Navigate(toolStripTextBox1.Text);
}
if (toolStripTextBox1.Text.StartsWith("http://"))
{
webBrowser1.Navigate(toolStripTextBox1.Text);
}
if (toolStripTextBox1.Text.StartsWith("https://"))
{
webBrowser1.Navigate(toolStripTextBox1.Text);
}
if (items.Any(item => toolStripTextBox1.Text.Contains(item)))
{
webBrowser1.Navigate(toolStripTextBox1.Text);
}
else
{
webBrowser1.Navigate("https://www.google.ca/?gws_rd=ssl#safe=active&q=" + toolStripTextBox1);
}
}
}
and it litteraly doesn't work. eg. I run it, no errors, all it does is play the windows error sound and won't be functional....
I know the code after the if statement is functional cause i have the exact same code on a button and it works just fine.
Use your code in key up event, not key down, this will make event fully executed and eligible to read the key pressed.
I have adjusted your code and it works, you don't have to use KeyChar just use KeyCode instead and it should work.
private void toolStripTextBox1_KeyUp(object sender, KeyEventArgs e)
{
if(e.KeyCode == Keys.Enter || e.KeyValue == (char)Keys.Return)
//if (e.KeyChar == (char)Keys.Enter || e.KeyChar == (char)Keys.Return)
{
var items = new[] { 500 + "objects here" };
if (toolStripTextBox1.Text.StartsWith("www."))
{
webBrowser1.Navigate(toolStripTextBox1.Text);
}
if (toolStripTextBox1.Text.StartsWith("http://"))
{
webBrowser1.Navigate(toolStripTextBox1.Text);
}
if (toolStripTextBox1.Text.StartsWith("https://"))
{
webBrowser1.Navigate(toolStripTextBox1.Text);
}
if (items.Any(item => toolStripTextBox1.Text.Contains(item)))
{
webBrowser1.Navigate(toolStripTextBox1.Text);
}
else
{
webBrowser1.Navigate("https://www.google.ca/?gws_rd=ssl#safe=active&q=" + toolStripTextBox1);
}
}
Make sure that the control has focus, or redirect the event to the control
https://msdn.microsoft.com/en-us/library/system.windows.forms.control.keydown%28v=vs.110%29.aspx
Try this for your KeyPress event handler:
private void toolStripTextBox1_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == (char)Keys.Enter || e.KeyChar == (char)Keys.Return)
{
//Insert code here
It sounds like the problem may be that the method is not bound to the KeyPress event.
In the designer, click on the textbox, and then over to the side where it lists all of the properties, there should be a lightning bolt looking icon, click on that, and then scroll down to KeyPress and make sure it says toolStripTextBox1_KeyPress
EDIT
Alternatively, you can add the event handler programmatically. In your Form_Load event, add the code
toolStripTextBox1.KeyPress += toolStripTextBox1_KeyPress;
and in your Form_Closed event handler, add
toolStripTextBox1.KeyPress -= toolStripTextBox1_KeyPress;

KeyPress F1 does not work C#

I'm designing a device app. Compact Framework 2.0
I want the user to press F1 to navigate to the next screen, but it does not work.
Can't seem to find a solution.
Is it possible?
This is how I normally use Keypress:
This works:
if (e.KeyChar == (char)Keys.M)
{
MessageBox.Show("M pressed");
e.Handled = true;
}
This dos NOT work:
if (e.KeyChar == (char)Keys.F1)
{
MessageBox.Show("F1 pressed");
e.Handled = true;
}
try this
private void Form1_Load(object sender, EventArgs e)
{
this.KeyPreview = true;
this.KeyDown += new KeyEventHandler(Form1_KeyDown);
}
void Form1_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode.ToString() == "F1")
{
MessageBox.Show("F1 pressed");
}
}
Refer This
You can override the ProcessCmdKey method of your form class and use keyData == Keys.F1 to check whether F1 is pressed. Above link has example as follows.
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
if (keyData == Keys.F1)
{
MessageBox.Show("You pressed the F1 key");
return true; // indicate that you handled this keystroke
}
// Call the base class
return base.ProcessCmdKey(ref msg, keyData)
}
Some keys(like f1,f2,arrow keys ,tab ....)cannot be "captured" by keychar for that you need to use keycode:
if (e.KeyCode == Keys.F1)
{
// do stuff
}
keychar property - http://msdn.microsoft.com/en-us/library/system.windows.forms.keypresseventargs.keychar.aspx
Use KeyDown instead of KeyPress:
private void Form1_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyData == Keys.F1)
{
// your code here
}
}
Also set KeyPreview to true

How do I capture the enter key in a windows forms combobox

How do I capture the enter key in a windows forms combo box when the combobox is active?
I've tried to listen to KeyDown and KeyPress and I've created a subclass and overridden ProcessDialogKey, but nothing seems to work.
Any ideas?
/P
Hook up the KeyPress event to a method like this:
protected void myCombo_OnKeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == 13)
{
MessageBox.Show("Enter pressed", "Attention");
}
}
I've tested this in a WinForms application with VS2008 and it works.
If it isn't working for you, please post your code.
In case you define AcceptButton on your form, you cannot listen to Enter key in KeyDown/KeyUp/KeyPress.
In order to check for that, you need to override ProcessCmdKey on FORM:
protected override bool ProcessCmdKey(ref Message msg, Keys keyData) {
if ((this.ActiveControl == myComboBox) && (keyData == Keys.Return)) {
MessageBox.Show("Combo Enter");
return true;
} else {
return base.ProcessCmdKey(ref msg, keyData);
}
}
In this example that would give you message box if you are on combo box and it works as before for all other controls.
or altertatively you can hook up the KeyDown event:
private void comboBox1_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
MessageBox.Show("Enter pressed.");
}
}
private void comboBox1_KeyDown( object sender, EventArgs e )
{
if( e.KeyCode == Keys.Enter )
{
// Do something here...
} else Application.DoEvents();
}
Try this:
protected override bool ProcessCmdKey(ref Message msg, Keys k)
{
if (k == Keys.Enter || k == Keys.Return)
{
this.Text = null;
return true;
}
return base.ProcessCmdKey(ref msg, k);
}
It could be that your dialog has a button that's eating the enter key because it's set to be the AcceptButton in the form property.
If that's the case then you solve this like this by unsetting the AcceptButton property when the control gets focus then resetting it back once the control loses focus ( in my code, button1 is the accept button )
private void comboBox1_Enter(object sender, EventArgs e)
{
this.AcceptButton = null;
}
private void comboBox1_Leave(object sender, EventArgs e)
{
this.AcceptButton = button1;
}
private void comboBox1_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyData == Keys.Enter)
{
MessageBox.Show("Hello");
}
}
I have to admit not liking my own solution as it seems a little hacky to unset/set the AcceptButton property so if anyone has a better solution then I'd be interested
protected void Form_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == 13) // or Key.Enter or Key.Return
{
MessageBox.Show("Enter pressed", "KeyPress Event");
}
}
Don't forget to set KeyPreview to true on the form.

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