2
How it is possible to validate in a TextBox
when the user type letters instead of numbers appear a warning:
is only allowed to enter numbers in this field
What function can I check with?
2
How it is possible to validate in a TextBox
when the user type letters instead of numbers appear a warning:
is only allowed to enter numbers in this field
What function can I check with?
2
You can use the code
private void textBox_KeyDown(object sender, KeyEventArgs e)
{
e.SuppressKeyPress = !((e.KeyCode >= Keys.D0 && e.KeyCode <= Keys.D9) || (e.KeyCode >= Keys.NumPad0 && e.KeyCode <= Keys.NumPad9) ||
(e.KeyCode == Keys.Tab || e.KeyCode == Keys.Back || e.KeyCode == Keys.Capital || e.KeyCode == Keys.CapsLock || e.KeyCode == Keys.Enter ||
e.KeyCode == Keys.Insert || e.KeyCode == Keys.Home || e.KeyCode == Keys.Delete || e.KeyCode == Keys.End || (e.KeyCode >= Keys.Left && e.KeyCode <= Keys.Down)));
if (e.SuppressKeyPress)
MessageBox.Show("só é permitido digitar números neste campo");
}
In this code, all that nay for number and special navigation and editing keys I select the property SuppressKeyPress
with true
to delete the down button.
1
private void textBox1_KeyPress(object sender, KeyPressEventArgs e) {
if (!char.IsControl(e.KeyChar) && !char.IsDigit(e.KeyChar) && (e.KeyChar != ',')) {
e.Handled = true;
}
if (e.Handled)
MessageBox.Show("Só é permitido digitar números neste campo");
}
Note that I added in condition to allow also our decimal separator , . If you want to allow only numbers, just withdraw the last condition.
if (!char.IsControl(e.KeyChar) && !char.IsDigit(e.KeyChar)) {
e.Handled = true;
}
References:
Add on your page one CompareValidator
and use the property DataTypeCheck
and in the Type
define as you wish:
...
Type="String|Integer|Double|Date|Currency"
...
<asp:CompareValidator runat="server" Operator="DataTypeCheck" Type="Integer"
ControlToValidate="TextBox1" ErrorMessage="Só é permitido digitar números neste campo"/>
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Web or Desktop?
– novic
A Javascript function would help you?
– Marconi