Wish to use text box to only allow numeric Data and backspace entry

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Wish to use text box to only allow numeric Data entry

Can any one help me with code for restricting other than numbers and backspace in text box.

Posted 8-Jun-11 22:24pm

Ragi Gopi

Updated 28-Mar-17 18:55pm

v3

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Comments

walterhevedeich 9-Jun-11 4:27am

Tag it. Windows forms or web application?

Ragi Gopi 9-Jun-11 4:28am

Windows forms

6 solutions

Solution 2

You could use a MaskedTextBox[^] with a Mask of "####" - that is what it's there for...

Posted 8-Jun-11 22:32pm

OriginalGriff

Solution 1

Try the MSDN article @
http://msdn.microsoft.com/en-us/library/ms229644(v=VS.90).aspx[^]

Posted 8-Jun-11 22:30pm

Wild-Programmer

Solution 3

You need a Masked textbox.

Here: Masked C# TextBox Control[^]

Further, you can also implement the functionality using OnKeyPress or OnKeyUp or OnBlur (there may be more events, pick any one that suits you). When the particular method event is raised, you can check for the key pressed or the text present/entered and act accordingly - show an alert/error/blankout.

Posted 8-Jun-11 22:34pm

Sandeep Mewara

Solution 6

C#

private void tbph_TextChanged_1(object sender, EventArgs e)
       {
           tbph.KeyPress += new KeyPressEventHandler(tbph_KeyPress);
       }
       private void tbph_KeyPress(object sender, KeyPressEventArgs e)
       {
           if ((e.KeyChar < '0') || (e.KeyChar > '9')) e.Handled = true;
       }

i tried above code ..
and got answer...

Posted 8-Jun-11 23:10pm

Ragi Gopi

Comments

Tarun.K.S 9-Jun-11 5:15am

How about copying a text, then pasting it( by right-clicking, then click paste on it). The text will appear.

Ragi Gopi 9-Jun-11 5:42am

ohhhhh..thats a problem.....

Solution 5

Javascript Function:

C#

function isOnlyNumber(field) {
      var e = event;
      var charCode = e.which || e.keyCode;
      if (charCode > 47 && charCode < 58)
      {
      return true;
      }
      else{
      return false;
      }

Use This Function in TextBox onkeypress event as below.

<asp:TextBox ID="txt1" runat="server" CssClass="inputbox" onkeypress="return isOnlyNumber(this);"></asp:TextBox>

Posted 8-Jun-11 22:56pm

Vijay Radia

Updated 8-Jun-11 23:07pm

v2

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CS2011 · Accepted Answer · 2011-06-08T22:35:00

Solution 4

On KeyPress event write following code

C#

if (char.IsNumber(e.KeyChar))
     e.Handled = false;
else
     e.Handled = true;

Posted 8-Jun-11 22:35pm

CS2011

Comments

RakeshMeena 9-Jun-11 4:42am

My 5! Though you don't need to put both If and else parts.

CS2011 9-Jun-11 4:47am

Thanks.

Tarun.K.S 9-Jun-11 4:59am

I beg to differ here, else *is* required.

CS2011 9-Jun-11 5:14am

What Else ?? :-)

Tarun.K.S 9-Jun-11 5:28am

Hahahhaaa! :D

Tarun.K.S 9-Jun-11 4:59am

Good answer Chanakya :). 5+

CS2011 9-Jun-11 5:14am

Thanks

Tarun.K.S 9-Jun-11 5:03am

I have one small doubt. If a user pastes any character(s) into the textbox(right-click on textbox, then paste), it unfortunately shows the character(s). Any suggestion how this can be prevented? Thank you.

CS2011 9-Jun-11 5:27am

you can disable to paste option if you want :-)

Tarun.K.S 9-Jun-11 5:29am

Lol that's the only solution in sight. :D

RakeshMeena 9-Jun-11 5:41am

Nop! Solutions are still available but a bit complex.
There are 2 ways you can paste in a textbox:
1. Ctrl + V : This is already disabled (because of original solution), so no problem.
2. Mouse right click and paste: Here we can handle MouseDown event and if the right button is clicked, save the textbox's text in a variable. Then on the TextChanged event, check if the text contains only numbers or not, if not previous value can be restored.

Hope that helps.

Tarun.K.S 9-Jun-11 7:30am

Aah that's a feasible solution, thanks for the heads up. :)

CS2011 9-Jun-11 7:05am

As Rakesh Told Ctrl+V is disabled and if you add
this.textBox1.ContextMenu = new ContextMenu();InitializeComponent() Then Your problem is solved :-). See not so hard afte all :-D

Tarun.K.S 9-Jun-11 7:32am

Another excellent solution, create a custom ContextMenu and don't add items in it which makes it feel like disabled. Perfect. Thanks! :)

Ragi Gopi 9-Jun-11 5:50am

How can we disable Paste option????

CS2011 9-Jun-11 7:03am

Ctrl+V is disabled already. Now if you want to disable Right Mouse Click Menu(i.e Copy,Past,etc) add following code this.textBox1.ContextMenu = new ContextMenu();

Ragi Gopi 9-Jun-11 7:36am

private void tbph_MouseClick(object sender, MouseEventArgs e)
{
this.tbph.ContextMenu = new ContextMenu();
}

Got Ans...
@CS2011
thankuuuu

Ragi Gopi 9-Jun-11 6:02am

thankuuuuu.....
its workssss
thank u all

Ragi Gopi 9-Jun-11 6:47am

if ((e.KeyChar < '0' || e.KeyChar > '9') && (e.KeyChar != '\b'))
{
MessageBox.Show("Only numbers Allowed");
e.Handled = true;
}
else
{
e.Handled = false;
}

atlast every thing is fine....

CS2011 9-Jun-11 6:56am

Yep..Otherwise backspace will not work.I knew that but wanted you to try it by your self.Good Work :-)

Ragi Gopi 9-Jun-11 7:03am

:)

Wild-Programmer 9-Jun-11 9:06am

Good answer, my 5 is in :)

CS2011 9-Jun-11 9:21am

Thanks Amit