B4J Question Validate TextField Entry

[BPak]

Is there a way of validating a TextField Entry as it is entered from the Keyboard.

For example: To only accept Alphabetical input
or to only receive numbers
or decimal numbers into the Textfield?

 

[Erel]

You can handle the TextChanged event and if the text contains a non-numeric character then delete it.

 

[gjoisa]

Can't we limit it while designing to numeric only or password mode like in B4A ?

 

[Erel]

There isn't an InputType property like in B4A. You can create a Password Field with the scene builder and then treat it as a TextField.

 

[BPak]

There isn't an InputType property like in B4A. You can create a Password Field with the scene builder and then treat it as a TextField.

Here is what I worked out for Text.. Not perfect but works for me.

Sub TrackEd_TextChanged (Old As String, New As String)
Dim len As Int
Dim chr1 As Char

If Old.ToUpperCase = New Then Return ' exits upper case change

len = New.Length
If len > 0 Then
New = New.ToUpperCase
For i = 0 To len-1
chr1 = New.CharAt(i)
If "ABCDEFGHIJKLMNOPQRSTUVWXYZ".Contains(chr1) = False Then
len = Old.Length
TrackEd.Text = Old
TrackEd.SetSelection(len, len)
Return
End If
Next
Else
TrackEd.Text = ""
Return
End If

TrackEd.Text = New ' text changed to upper case
TrackEd.SetSelection(len, len)
End Sub