How to validate textbox on key down event to accept only numbers in silverlight 4

vijay rags

15y19.1k

Hi,

i need a validation to check whether key pressed down is numeric or not. i tried with different code but they cant help me out.In the textbox if the user press Shift+numbers it displays special charcters like !,@,#...... I need to validate the Shift + key down event. Please find the sample code i tried below and help me out.

private void txtNumericTextbox_KeyDown(object sender, KeyEventArgs e)
        {
            try
            {
                if (e.Key < Key.D0 || e.Key > Key.D9)
                {
                    if (e.Key < Key.NumPad0 || e.Key > Key.NumPad9)
                    {
                        if (e.Key != Key.Back)
                        {
                            txtNumericTextbox_.BorderBrush = new SolidColorBrush(Colors.Red);
                            lblErrorMessage.Visibility = Visibility.Visible;
                            lblErrorMessage.Text = "Please Enter Numbers Only";
                        }
                        else
                        {
                            txtNumericTextbox_.BorderBrush = new SolidColorBrush(Colors.DarkGray);
                            lblErrorMessage.Visibility = Visibility.Collapsed;
                            lblErrorMessage.Text = "";
                        }
                    }
                }

Thanks,
Vijay

7 Replies

Know the answer? Post it — somebody with the same question will find it here.

Pravin More15y ago
Accepted answer
Hi Vijay,

You can use the ModifierKeys property on control to determine if the shift key is being held.
if (Control.ModifierKeys == Keys.Shift )
{ ... }

and other code is correct for detecting number.

Thanks,
Pravin.
0
Riddhi Valecha13y ago
Hi...There is no KeyPress Event in Silverlight Textboxes...

The code for numbers worked out....

Try this for alphabets -

if (((e.Key > Key.D0 && e.Key <= Key.D9) || (e.Key >= Key.NumPad0 && e.Key <= Key.NumPad9) || e.Key == Key.Back || e.Key == Key.Tab))
e.Handled = true;

else

{
e.Handled = false;
}
0
Pradip Pandey13y ago
Hi Riddhi

If it helped, please mark this as Accepted Answer.
0
Riddhi Valecha13y ago
Hi...

Thanks a lot............

yes... this code worked out for me !!!!!
0
Pradip Pandey13y ago
Hi Riddhi

Use this to accept only numeric values. Event you can choose textBox1_KeyDown
nonnumberenter = false;
if (e.KeyCode < Keys.D0 || e.KeyCode > Keys.D9)
{
if (e.KeyCode < Keys.NumPad0 || e.KeyCode > Keys.NumPad9)
{
if (e.KeyCode != Keys.Back)
{
nonnumberenter = true;
string abc = "Please enter numbers only.";
DialogResult result1 = MessageBox.Show(abc.ToString(), "Validate numbers", MessageBoxButtons.OK);
}
}
}
if (Control.ModifierKeys == Keys.Shift)
{
nonnumberenter = true;
string abc = "Please enter numbers only.";
DialogResult result1 = MessageBox.Show(abc.ToString(), "Validate numbers", MessageBoxButtons.OK);

}

Use this to accept only characters. Event you can choose textBox1_KeyPress
if (Char.IsNumber(e.KeyChar) || Char.IsSymbol(e.KeyChar) || Char.IsWhiteSpace(e.KeyChar) || Char.IsPunctuation(e.KeyChar))
{
MessageBox.Show("Only Char are allowed");
e.Handled = true;
}

Hope it will help.
0
Riddhi Valecha13y ago
Hi all...

Please help me out ... I am having the same problem...

There are 2 textboxes:

1st textbox - should accept only numeric values and 2nd should accept only characters value..

I am not getting how to do this...

Please help...

Thanks in advance !!
0
Priya Linge15y ago
Hi,

Please try this,

private void usertext_KeyDown(object sender, KeyEventArgs e)
        {
            if (Keyboard.Modifiers == ModifierKeys.Shift)
            {
                e.Handled = true;
               MessageBox.Show("Please Enter Numbers Only");
            }
           if (!e.Handled && (e.Key < Key.D0 || e.Key > Key.D9))
           {
               if (e.Key < Key.NumPad0 || e.Key > Key.NumPad9)
               {
                      if (e.Key != Key.Back)
                    {
                             e.Handled = true;
                    }
                }
           }
        }
Hope this will help you.
Thanks.
0