How to clear last number on textbox (type data double)

Question

1.00/5 (1 vote)

See more:

i have two textbox...
on TextBox1_TextChanged event i set
textbox2.text=textbox1.text
the problem when i clear all number on textbox1..
in textbox2 still have one number if i press 0 on textbox1,
then textbox2 is clear ..
why like that? and how to solved it?

What I have tried:

If TextBox1.Text = "" Or Not IsNumeric(TextBox1.Text) Then
           Exit Sub
       End If
       Dim a As Double
       a = TextBox1.Text
       TextBox1.Text = Format(a, "#,###")
       TextBox1.SelectionStart = Len(TextBox1.Text)


       TextBox2.Text = TextBox1.Text

Posted 28-Jul-17 2:30am

Khabibb Mubarakk

Updated 28-Jul-17 2:40am

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Graeme_Grant · Answer 1 · 2017-07-28T02:40:00

You need to test the key before the text is changed and cancel/suppress if invalid.

VB

Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged

    Dim a As Double
    a = TextBox1.Text
    TextBox1.Text = Format(a, "#,###")
    TextBox1.SelectionStart = Len(TextBox1.Text)
    TextBox2.Text = TextBox1.Text

End Sub

Private Sub TextBox1_KeyDown(sender As Object, e As KeyEventArgs) Handles TextBox1.KeyDown

    If e.KeyCode < Keys.D0 Or e.KeyCode > Keys.D9 Then
        e.SuppressKeyPress = True
    End If

End Sub

Update: If you want to allow edit keys as well, here is an updated version of the KeyDown event.

VB

Private validKeys() As Integer =
{
    Keys.Delete,
    Keys.Back,
    Keys.Clear,
    Keys.Home,
    Keys.Left,
    Keys.Right,
    Keys.End,
    Keys.D0,
    Keys.D1,
    Keys.D2,
    Keys.D3,
    Keys.D4,
    Keys.D5,
    Keys.D6,
    Keys.D7,
    Keys.D8,
    Keys.D9
}

Private Sub TextBox1_KeyDown(sender As Object, e As KeyEventArgs) Handles TextBox1.KeyDown

    If Not validKeys.Contains(e.KeyCode) Then
        e.SuppressKeyPress = True
    End If

End Sub