Text box validation for numbers and decimal in c#

Question

Hi to all
I need a solution for How to restrict a textbox to allow two numbers before and after the decimal point (Like 12.12 , 23.22 ,25.65 only) in Keypress event. Igot the after the decimal point,but i didn't get the before the decimal point .please reply me

Regards
Nagaraju T

Iftikar Hussain · Answer

In that case use MaskTextBox, which is predefined format will restrict user to input the data. Please refer the below link http://www.dotnetperls.com/maskedtextbox Regards, Iftikar

Tushar Jagdale · Answer

Try this one , You can do all validation like String,Number,Mobile,email,website,percent,Rupees in single line of codein C#.NET https://www.youtube.com/watch?v=ALTwAUY5M-0 :)

NAGARAJU TAMADA · Answer

Thanks for the reply Sir This answer suitable for my Query Thanks & Regards NagaRaju T

NAGARAJU TAMADA · Answer

Its not working sir. The below code accepts only numbers and accept only two digits after the decimal point its working fine.But I want it accepts 2 digits before the decimal also like 12. only Please solve this private void txtRecieve_KeyPress(object sender, KeyPressEventArgs e) { if (!char.IsControl(e.KeyChar) && !char.IsDigit(e.KeyChar) && e.KeyChar != '.' && e.KeyChar != ',') { e.Handled = true; } //check if '.' , ',' pressed char sepratorChar = 's'; if (e.KeyChar == '.' || e.KeyChar == ',') { // check if it's in the beginning of text not accept if (txtRecieve.Text.Length == 0) e.Handled = true; // check if it's in the beginning of text not accept if (txtRecieve.SelectionStart == 0) e.Handled = true; // check if there is already exist a '.' , ',' if (alreadyExist(txtRecieve.Text, ref sepratorChar)) e.Handled = true; //check if '.' or ',' is in middle of a number and after it is not a number greater than 99 if (txtRecieve.SelectionStart != txtRecieve.Text.Length && e.Handled == false) { // '.' or ',' is in the middle string AfterDotString = txtRecieve.Text.Substring(txtRecieve.SelectionStart); if (AfterDotString.Length > 2) { e.Handled = true; } } } //check if a number pressed if (Char.IsDigit(e.KeyChar)) { //check if a coma or dot exist if (alreadyExist(txtRecieve.Text, ref sepratorChar)) { int sepratorPosition = txtRecieve.Text.IndexOf(sepratorChar); string afterSepratorString = txtRecieve.Text.Substring(sepratorPosition + 1); if (txtRecieve.SelectionStart > sepratorPosition && afterSepratorString.Length > 1) { e.Handled = true; } } } }

Iftikar Hussain · Answer

then do like this private void textBox1_KeyPress(object sender, KeyPressEventArgs e) { var text = textBox1.Text.Trim(); if (Regex.IsMatch(text, @"^\d{1,2}(\.\d{1,2})?$")) { // Do something here } } Regards, Iftikar

NAGARAJU TAMADA · Answer

There is no change in my data. I need exact decimal points in my data,that's why I asked this query Regards NagaRaju

Iftikar Hussain · Answer

then tell me what should be happen if i enter like 12. Regards, Iftikar

NAGARAJU TAMADA · Answer

Thank you for Answer sir, But I need only Key pressing But not Validation When I enter 2 digits After i only enter "." and then only 2 digits Ex:12.23, 23.12 ...................... It is very useful my project please reply to me Regards NagaRaju T

Iftikar Hussain · Answer

yes, here it is this.textBox1.KeyPress += new KeyPressEventHandler(this.textBox1_KeyPress); private void textBox1_KeyPress(object sender, KeyPressEventArgs e) { var text = textBox1.Text.Trim(); if (Regex.IsMatch(text, @"^\d{1,2}(\.\d{1,2})?$")) { // Do something here } else { MessageBox.Show("Doesn't match pattern"); } } Regards, Iftikar

NAGARAJU TAMADA · Answer

Thanks for ur answer .I already checked above answer.But Is it Possible in KeyPress Event Or not? Regards NagaRaju T

Iftikar Hussain · Answer

Hi, Try like this you need to do this after entering the data in textbox this.textBox2.Leave += new System.EventHandler(this.textBox1_TextLeave); private void textBox1_TextLeave(object sender, EventArgs e) { var text = textBox1.Text.Trim(); if (Regex.IsMatch(text, @"^\d{1,2}(\.\d{1,2})?$")) { // Do something here } else { MessageBox.Show("Doesn't match pattern"); } } Regards, Iftikar

Pankaj Pandey · Answer

hii create a function in which split the textbox data by ".". var x=txtbox.text.Split("."); string y=x[0].tostring(); string z=x[1].tostring(); now check that if x.lenght>2 or y.length>2 then raise validation.

Text box validation for numbers and decimal in c#

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Answers (12)