Check a string for valid characters

[Vusys]

Apologies for posting a question on my first post, anyhow, could someone suggest an idea to turn this into working VB6 code:

ValidChars = "0123456789 ABC"

If (TextBox1.Text only contains characters from ValidChars) then
' Do whatever '
Else
' Do something else '
EndIf

[debasisdas]

Check using string function to find out the position of the character.

If that is not 0 then it is a valid character so accept only those else don't accept.

[QVeen72]

Hi,

Instead of checking for Validated data inside textbox, dont allow the user to enter Invalid data.. This is called as "Input Validation" accept only required data. write this code in Keypress event of Textbox:

[code=vb6]
Dim ValidChars As String
ValidChars = "0123456789 ABC"
If KeyAscii <> 8 Then 'Allow BackSpace
If InStr(ValidChar s, Chr(KeyAscii)) =0 Then KeyAscii=0
End If
[/code]

Regards
Veena

[mafaisal]

Hello
U can use Instr Function for this
eg

dim ValidChars as string
ValidChars = "0123456789ABC"
Dim i,Flag as integer
Flag =0
For i = 0 to len(Textbox1.text)
 If InStr(1, ValidChars , mid(Textbox1.text,i,1)) = 0 then ' Not valid
   Flag =1
 End if 
Next
If Flag = 1 then 'Not Valid
  ' Do whatever '
Else
  ' Do something else '
EndIf

Try

Faisal

[Vusys]

Thank you all for the quick responces,

Hi,

Instead of checking for Validated data inside textbox, dont allow the user to enter Invalid data.. This is called as "Input Validation" accept only required data. write this code in Keypress event of Textbox:

[code=vb6]
Dim ValidChars As String
ValidChars = "0123456789 ABC"
If KeyAscii <> 8 Then 'Allow BackSpace
If InStr(ValidChar s, Chr(KeyAscii)) =0 Then KeyAscii=0
End If
[/code]

Regards
Veena

I should have been more clear in my first post, but I'm actually putting the text into a string and then checking it, since the textbox is used for more than one thing.

Hello
U can use Instr Function for this
eg

dim ValidChars as string
ValidChars = "0123456789ABC"
Dim i,Flag as integer
Flag =0
For i = 0 to len(Textbox1.text)
 If InStr(1, ValidChars , mid(Textbox1.text,i,1)) = 0 then ' Not valid
   Flag =1
 End if 
Next
If Flag = 1 then 'Not Valid
  ' Do whatever '
Else
  ' Do something else '
EndIf

Try

Faisal

I tried this in my project, and an empty new one to check the code and got this both times:

Run-time error '5':
Invalid procedure call or argument.

[QVeen72]

Hi,

Change the For loop parameters:

For i = 1 to len(Textbox1.te xt)

Regards
Veena

[Vusys]

Hi,

Change the For loop parameters:

For i = 1 to len(Textbox1.te xt)

Regards
Veena

Aha. Thank you kindy, this works just as needed. :]

[Killer42]

[CODE=vb]
' ...
Flag = 0
For i = 1 to Len(Textbox1.Te xt)
If InStr(1, ValidChars , Mid(Textbox1.Te xt, i, 1)) = 0 Then
Flag =1
End If
Next
[/CODE]
Just wanted to point out that as a general rule, you should immediately exit the loop once you have found the situation you're looking for. In other words, in this example you would insert Exit For after line 5.