First of all, thanks for answers! 9 total answers. Thank you.
Bad news: all of the answers had some quirks or didn't work quite right (or at all). I've added a comment to each of your posts.
Good news: I've found a way to make it work. This solution is pretty straightforward and seems to work in all the scenarios (mousing down, selecting text, tabbing focus, etc.)
bool alreadyFocused;
...
textBox1.GotFocus += textBox1_GotFocus;
textBox1.MouseUp += textBox1_MouseUp;
textBox1.Leave += textBox1_Leave;
...
void textBox1_Leave(object sender, EventArgs e)
{
alreadyFocused = false;
}
void textBox1_GotFocus(object sender, EventArgs e)
{
// Select all text only if the mouse isn't down.
// This makes tabbing to the textbox give focus.
if (MouseButtons == MouseButtons.None)
{
this.textBox1.SelectAll();
alreadyFocused = true;
}
}
void textBox1_MouseUp(object sender, MouseEventArgs e)
{
// Web browsers like Google Chrome select the text on mouse up.
// They only do it if the textbox isn't already focused,
// and if the user hasn't selected all text.
if (!alreadyFocused && this.textBox1.SelectionLength == 0)
{
alreadyFocused = true;
this.textBox1.SelectAll();
}
}
As far as I can tell, this causes a textbox to behave exactly like a web browser's address bar.
Hopefully this helps the next guy who tries to solve this deceptively simple problem.
Thanks again, guys, for all your answers that helped lead me towards the correct path.
Two options:
Use a NumericUpDown
instead. NumericUpDown does the filtering for you, which is nice. Of course it also gives your users the ability to hit the up and down arrows on the keyboard to increment and decrement the current value.
Handle the appropriate keyboard events to prevent anything but numeric input. I've had success with this two event handlers on a standard TextBox:
private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
if (!char.IsControl(e.KeyChar) && !char.IsDigit(e.KeyChar) &&
(e.KeyChar != '.'))
{
e.Handled = true;
}
// only allow one decimal point
if ((e.KeyChar == '.') && ((sender as TextBox).Text.IndexOf('.') > -1))
{
e.Handled = true;
}
}
You can remove the check for '.'
(and the subsequent check for more than one '.'
) if your TextBox shouldn't allow decimal places. You could also add a check for '-'
if your TextBox should allow negative values.
If you want to limit the user for number of digit, use: textBox1.MaxLength = 2; // this will allow the user to enter only 2 digits
Best Answer
(I'm assuming that you are using WinForms)
What you have said you have already tried does work.
If you handle the Enter event on the text box, you can set the selection to nothing:
This sets the selection to be a zero-length string starting at the end of the text currently in the text box. This is to position the caret at the end of the current text.