Develop Reference

Use enter key to send text to a rich text box

I am currently using winforms and I want to send the text from a textbox to a rich text box by pressing enter. Here is the code I currently have
private void textBox1_TextChanged(object sender, EventArgs e)
{
}
private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
richTextBox1.Text = textBox1.Text;
e.Handled = true;
}
}
What am I missing? Thanks in advance.

Did you subscribe to the event KeyDown? You can add a break point in textBox1_KeyDown to check it.
If the break point is not triggered, you can delete textBox1_KeyDown and double click the Button to re-generate it. Then will subscribe to the event "KeyDown" automatically.
Another way is that you can subscribe to events through code.
public Form1()
{
InitializeComponent();
textBox1.KeyDown += textBox1_KeyDown;
}

How to change text of Label while typing in TextBox

Please I'm new to C#, I created a textBox and a label. What i am expecting is, if I type a value into the textBox, I want it to display on the label and if I change the value it should also change immediately on the label.
it work with the code below and i press enter key
private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
label1.Text = textBox1.Text;
}
}
But I want it without press Enter/Return Key on keyboard.
Thanks for understanding

This works for VisualStudio
Select your TextBox in the Designer, go to the it's properties and click on the events (teh icon with the lightning). Then make a double click on the event that is called: TextChanged.
This creates a new function, that will always be called when the text of your TextBox changes. Insert following code into the function:
private void textBox1_TextChanged(object sender, EventArgs e)
{
TextBox tb = sender as TextBox;
label1.Text = tb.Text;
}
That's it.

label.DataBindings.Add("Text", textBox, "Text");

textbox KeyDown/Up/Press events may help.
For example
private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
label1.Text += e.KeyData.ToString();
}

C# WinForms: bring back focus to form after button click

my simple WinForms app consists of one Form which has 2 important methods:
private void MainWindow_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Q)
{
qKeyPressed = true;
}
keyTimer.Start();
}
private void MainWindow_KeyUp(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Q)
{
qKeyPressed = false;
}
keyTimer.Stop();
}
In form's constructor I use button1.TabStop = false; to set button1 focus to false, so my form can handle methods KeyUp and KeyDown. I want my form to be focused even after button1 click event. I tried:
button1.TabStop = false;
this.Focus();
in private void button1_Click(object sender, EventArgs e) but this doesn't seem to work and button after click looks like focused and methods KeyUp and KeyDown are disabled. How can my problem be solved? Thanks in advance

Run this in the button click function:
this.ActiveControl = null;
When you click the button, you set it as the active control. Removing this property will let you put focus on your form.

How can I override the default button on a form when focus is in a TextBox

I have a winform form which has typical OK and Cancel buttons.
The OK button is set as the default button. When the user presses the ENTER key, the form is closed.
The form also has a text box which has a Search button beside it. The text box allows the user to enter search text and the Search button initiates the search function.
I would like the user to be able to press the ENTER key when the text box has the input focus and have the search function activate.
The problem is that the form is grabbing the ENTER key event before the text box's handler gets it.
EDIT: I've tried using the following event handlers, but they never get hit, and the form closes when the Enter key is hit:
private void txtFilter_KeyUp(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
Search();
e.Handled = true;
}
}
private void txtFilter_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
Search();
e.Handled = true;
}
}
I've also tried enabling the KeyPreview property on the form and implementing a KeyDown event handler for the form, but the Enter key never seems to cause any of these to be hit.
What is the best way to accomplish this?

Try handling the Enter and Leave events of the TextBox to clear out your form's AcceptButton property:
private void txtFilter_Enter(object sender, EventArgs e) {
this.AcceptButton = null;
}
private void txtFilter_Leave(object sender, EventArgs e) {
this.AcceptButton = closeButton;
}
Then you can just process your KeyUp event as your want:
private void txtFilter_KeyUp(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
Search();
}
}

Add a KeyDown event handler to the textBox and then add this to it
if (e.KeyCode == Keys.Enter)
{
btnSearch.PerformClick();
}

Alternative to set focus from within the Enter event

I have a textbox and in some cases in Enter event I need to set the focus to a different textbox.
I tried that code:
private void TextBox1_Enter(object sender, EventArgs e)
{
if(_skipTextBox1) TextBox2.Focus();
}
But this code doesn't work. After that I found on MSDN:
Do not attempt to set focus from within the Enter, GotFocus, Leave, LostFocus, Validating, or Validated event handlers.
So how can I do it other way?

Postpone executing the Focus() method until after the event is finished executing. Elegantly done by using the Control.BeginInvoke() method. Like this:
private void textBox2_Enter(object sender, EventArgs e) {
this.BeginInvoke((MethodInvoker)delegate { textBox3.Focus(); });
}

You could handle the KeyPress event instead:
private void TextBox1_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == (char)Keys.Return)
{
e.Handled = true;
TextBox2.Focus();
}
}

textBox.Select();
or
textBox.Focus();
or
set TabIndex = 0 from properties of that textBox.
both methods are use to set focus on textBox in C#, .NET