Android Question how to limit the user to type no more than one dot ( . ) on a edittext box view

MiguelCZ · Mar 3, 2014

Hi All, this is my first post here an also my first android app ( first overall program ), a simple calculator.
I want to limit the user to type no more than one dot, I do not know how to do it. If you look at the image I uploaded you can see that I can type as many as I want.

this is the simple code I have for that button

B4X:

Sub Button11_Click
  
    Vibrate.Vibrate(30)
  
    EditText1.Text = EditText1.Text & "."
  
End Sub

Thanks.

Peter Simpson · Mar 3, 2014

Hello,
Try this

B4X:

Dim EditText1 As EditText
    EditText1.Initialize(Null)
    EditText1.Text = "012345.6789"
If EditText1.Text.Contains(".") Then ToastMessageShow("I found ....... so do not add it again :-)", False)

The above code should work for you.

LucaMs · Mar 3, 2014

B4X:

EditText1.InputType = EditText1.INPUT_TYPE_DECIMAL_NUMBERS

MiguelCZ · Mar 3, 2014

B4X:

Dim EditText1 As EditText
    EditText1.Initialize(Null)
    EditText1.Text = "012345.6789"
If EditText1.Text.Contains(".") Then ToastMessageShow("I found ....... so do not add it again :-)", False)

The above code should work for you.[/quote]

LucaMs said:
B4X:

EditText1.InputType = EditText1.INPUT_TYPE_DECIMAL_NUMBERS

wow, thank you so much guys.

thanks,
edit, not working

LucaMs · Mar 3, 2014

You can put it in the code (Activity_Create) or in the Designer:

MiguelCZ · Mar 3, 2014

LucaMs said:
You can put it in the code (Activity_Create) or in the Designer:

View attachment 23168

Thank you. I did it on the designer but I still can type as many "." as I want

MiguelCZ · Mar 3, 2014

Peter Simpson said:
Hello,
Try this

B4X:

Dim EditText1 As EditText EditText1.Initialize(Null) EditText1.Text = "012345.6789" If EditText1.Text.Contains(".") Then ToastMessageShow("I found ....... so do not add it again :-)", False)

The above code should work for you.

looking at it again. using this code, as soon as I press the "." button it will not let me type anything else. not even Clear button

B4X:

Sub Button11_Click
  
    Vibrate.Vibrate(30)
  
    EditText1.Text = EditText1.Text & "."
  
    EditText1.Initialize(Null)
    EditText1.Text = "012345.6789"
  
    If EditText1.Text.Contains(".") Then
    ToastMessageShow("blabla", False)
    End If
  
End Sub

Peter Simpson · Mar 3, 2014

You could always check for a dot press before hand, when the dot is pressed it sets a flag(Boolean) to True so that you know that a dot has been used, thus it can't be used again until the C button is presses.

Or you can always use a regular expression RegEx. use [.] as the pattern. The dot is a special character in a Regular Expressions, so you would have to escape the character first...

MiguelCZ · Mar 3, 2014

Peter Simpson said:
You can always use a regular expression RegEx.

I do not know how to use it,
can you give me an example

LucaMs · Mar 3, 2014

You can use something like this:

B4X:

Sub EditText1_TextChanged (Old As String, New As String)
    If Old.Contains(".") Then
        If Asc(New.SubString(New.Length-1)) = Asc(".") Then
            EditText1.Text = Old
            EditText1.SelectionStart = Old.Length
        End If
    End If
End Sub

Peter Simpson · Mar 3, 2014

A quick tutorial by Erel

http://www.b4x.com/android/forum/threads/regular-expressions-tutorial.7123/

MiguelCZ · Mar 3, 2014

LucaMs said:

You can use something like this:

B4X:

Sub EditText1_TextChanged (Old As String, New As String)
    If Old.Contains(".") Then
        If Asc(New.SubString(New.Length-1)) = Asc(".") Then
            EditText1.Text = Old
            EditText1.SelectionStart = Old.Length
        End If
    End If
End Sub

using this code, for example if I type 2.2 then it works it wil not let me type another ".".
but if I type 2. and then I press "." again it will crash the app, see attached file

Peter Simpson said:
A quick tutorial by Erel

http://www.b4x.com/android/forum/threads/regular-expressions-tutorial.7123/

thanks, will read through that

MiguelCZ · Mar 3, 2014

Well I think I solved the problem , I used this code and it worked

B4X:

Sub Button11_Click
   
    Vibrate.Vibrate(30)
   
    If EditText1.Text.Contains(".") Then
    EditText1.Text = EditText1.Text
    Else
    EditText1.Text = EditText1.Text & "."
    End If
   
End Sub

Thank you guys for helping me

mangojack · Mar 3, 2014

I agree Lucas's code does cause a crash if you type 'consecutive' decimal points. trying alternatives as we speak

I don't see how your code above stops users typing multiple "."
to me it just makes sure the text DOES contain a decimal point ?

LucaMs · Mar 3, 2014

Be careful to use the point as a decimal: English syntax provides the point as a decimal and a comma to separate the thousands elsewhere (in Italy, for example) vice versa

DonManfred · Mar 3, 2014

In germany it is "12.345,67" too

Theera · Mar 3, 2014

This example from Klaus' guide, I had used before.

B4X:

AddPeriod
      If cboRName.SelectedItem.Length >0 Then
        If SelectQTY_or_LotNo= 1 AND LayOutDefault= True Then
            If txtQty.text.Length > 0 Then
                    If txtQty.text = Round(txtQty.text) Then 'checks if the user already pressed period or 0 is the first char
                            writeNumber(".")
                    End If
            Else
                    writeNumber("0") 'adds 0 if it is the first char
                    writeNumber (".")
            End If
        End If 
  End If     
End Sub

and filter use alike this

B4X:

Dim IME As IME
        IME.Initialize("IME")
           IME2SetCustomFilter(send,send.INPUT_TYPE_NUMBERS, "0123456789.")

mangojack · Mar 3, 2014

this will allow users to type a single Decimal point then allow ONLY 0-9 entries.. (Disables the decimal key)

in globals place

B4X:

  Dim FilterFlag As Boolean = False

then ...

B4X:

Sub EditText1_TextChanged (Old As String, New As String)

   If FilterFlag = False Then
     If New.Contains(".") Then
       FilterFlag = True
       FilterEntrys
     End If
   End If

End Sub

Sub FilterEntrys

  Dim im As IME
  Dim sb As StringBuilder
  sb.Initialize

  For i = 48 To 57
  sb.Append(Chr(i)) '0 - 9
  Next

  im.SetCustomFilter(EditText1, Bit.OR(EditText1.INPUT_TYPE_DECIMAL_NUMBERS,524288) , sb.ToString) '524288 - no suggestions

End Sub

MiguelCZ · Mar 3, 2014

thanks. will try the others alternatives

MiguelCZ · Mar 3, 2014

mangojack said:

this will allow users to type a single Decimal point then allow ONLY 0-9 entries.. (Disables the decimal key)

in globals place

B4X:

  Dim FilterFlag As Boolean = False

then ...

B4X:

Sub EditText1_TextChanged (Old As String, New As String)

   If FilterFlag = False Then
     If New.Contains(".") Then
       FilterFlag = True
       FilterEntrys
     End If
   End If

End Sub

Sub FilterEntrys

  Dim im As IME
  Dim sb As StringBuilder
  sb.Initialize

  For i = 48 To 57
  sb.Append(Chr(i)) '0 - 9
  Next

  im.SetCustomFilter(EditText1, Bit.OR(EditText1.INPUT_TYPE_DECIMAL_NUMBERS,524288) , sb.ToString) '524288 - no suggestions

End Sub

leaving the "." button like this,

B4X:

Sub Button11_Click
 
    Vibrate.Vibrate(30)
 
    EditText1.Text = EditText1.Text & "."
 
End Sub

and using your code, is not working, do I have to add something else?

Android Question how to limit the user to type no more than one dot ( . ) on a edittext box view

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