[RESOLVED] [2008] Numbers only, No characters allowed

[onlyGirl]

How would you let a user know that alpha characters are not allowed and only integers?

[.paul.]

use tooltips + or restrict user input to integers.
whats it for?

[stanav]

Have a label saying so sitting right next to the control of interest
If the control is a textbox, I'd change it and use a numericupdown control. That way, the user can't type in non-numeric values.

[onlyGirl]

use tooltips + or restrict user input to integers.
whats it for?

It's for data in a datagridview. Only numbers should be allowed. How can I restrict their input to integers?

[stanav]

It's for data in a datagridview. Only numbers should be allowed. How can I restrict their input to integers?

You would handle one of the keyboard event of the DataGridViewTextBoxEditingControl, and perform your test to see if the character being typed in is numeric.

[kleinma]

You would handle one of the keyboard event of the DataGridViewTextBoxEditingControl, and perform your test to see if the character being typed in is numeric.

I wouldn't restrict their keyboard input, I would just validate it as they type using the textchanged event. The problem with validating on the keyboard input is that you leave the door open for things like a right click/paste of something they copied to the clipboard. It won't be caught by a keyevent, and you end up with alpha characters in your numbers only box.

Likewise you don't want to disallow copy/paste functionality, because maybe what they are pasting really is all numbers, and its convenient for them to do so.

That is why textchanged is the best place to validate as they type.

[onlyGirl]

I wouldn't restrict their keyboard input, I would just validate it as they type using the textchanged event. The problem with validating on the keyboard input is that you leave the door open for things like a right click/paste of something they copied to the clipboard. It won't be caught by a keyevent, and you end up with alpha characters in your numbers only box.

Likewise you don't want to disallow copy/paste functionality, because maybe what they are pasting really is all numbers, and its convenient for them to do so.

That is why textchanged is the best place to validate as they type.

Could you give me a quick example please?

[kleinma]

do you want just integer numbers, or are you allowing decimals?

[onlyGirl]

do you want just integer numbers, or are you allowing decimals?

Well the datatype in the db is double. So yes decimals.

[JuggaloBrotha]

Why not use the NumericUpDown control for this, much easier than modifying a textbox since the NUD was built for this.

[GeekInOhio]

There are probably more elegant ways to do this, but here is what I came up with...

Function illegalCharacterCheck(ByVal testMe As String) As Boolean
 
Dim errorCount as Integer = 0
 
                   Dim acceptable As String = "0123456789."
            Dim i As Integer
            Dim letter As String = ""
            For i = 0 To testMe.Length - 1
                letter = testMe.Chars(i)
                If InStr(acceptable, letter) = 0 Then
                    errorCount = errorCount + 1
                Else
                    
                End If
 
            Next    
 
            If errorCount > 0
 
            Return TRUE
 
            Else
 
            Return False
            
            End If
End Function

To use it, you call illegalCharacterCheck() with the string you want to test. It returns a Boolean of True or False, with TRUE meaning we have an illegal character.

I use in on textchanged events and handle a TRUE bypulling focus back to the textbox, cell, etc, changing the background color to yellow, lighting up an invalid character(s) lablel, etc.

Example:

If illegalCharacterCheck(myText.Text) = True Then
            InvalidLabel1.Visible = True
            myText.Focus()
            myText.BackColor = Color.Yellow
        Else
            InvalidLabel1.Visible = False
            myText.BackColor = Color.Empty
        End If

You could also disable, enable the submit/ok button, etc.

Incidentally, you can make a minor modification to the above and use it to test for characters you don't want:

...
 Dim unacceptable As String = "0123456789!@#$%^&*()<>,.;:'[]{}+=_"""
            Dim i As Integer
            Dim letter As String = ""
            For i = 0 To testMe.Length - 1
                letter = testMe.Chars(i)
                If InStr(unacceptable, letter) > 0 Then
                    errorCount = errorCount + 1
                Else
                    
                End If
            Next
...

Hope it helps.

[JuggaloBrotha]

One thing I don't get is why do people repeatedly modify the TextBox control to do things that other controls where designed to do.

It seems like everyone loves to do more work than needed.

[stanav]

One thing I don't get is why do people repeatedly modify the TextBox control to do things that other controls where designed to do.

It seems like everyone loves to do more work than needed.

It's a DataGridView control, and the DGV doesn't have a DataGridViewNumericUpDownColumn out of the box. That's why people try to work with the DataGridViewTextBoxColumn, which uses the DataGridViewTextBoxEditingControl as the editing control.

[onlyGirl]

There are probably more elegant ways to do this, but here is what I came up with...

Function illegalCharacterCheck(ByVal testMe As String) As Boolean
 
Dim errorCount as Integer = 0
 
                   Dim acceptable As String = "0123456789."
            Dim i As Integer
            Dim letter As String = ""
            For i = 0 To testMe.Length - 1
                letter = testMe.Chars(i)
                If InStr(acceptable, letter) = 0 Then
                    errorCount = errorCount + 1
                Else
                    
                End If
 
            Next    
 
            If errorCount > 0
 
            Return TRUE
 
            Else
 
            Return False
            
            End If
End Function

To use it, you call illegalCharacterCheck() with the string you want to test. It returns a Boolean of True or False, with TRUE meaning we have an illegal character.

I use in on textchanged events and handle a TRUE bypulling focus back to the textbox, cell, etc, changing the background color to yellow, lighting up an invalid character(s) lablel, etc.

Example:

If illegalCharacterCheck(myText.Text) = True Then
            InvalidLabel1.Visible = True
            myText.Focus()
            myText.BackColor = Color.Yellow
        Else
            InvalidLabel1.Visible = False
            myText.BackColor = Color.Empty
        End If

You could also disable, enable the submit/ok button, etc.

Incidentally, you can make a minor modification to the above and use it to test for characters you don't want:

...
 Dim unacceptable As String = "0123456789!@#$%^&*()<>,.;:'[]{}+=_"""
            Dim i As Integer
            Dim letter As String = ""
            For i = 0 To testMe.Length - 1
                letter = testMe.Chars(i)
                If InStr(unacceptable, letter) > 0 Then
                    errorCount = errorCount + 1
                Else
                    
                End If
            Next
...

Hope it helps.

How would you put the focus back on the cell of the dgv?

[riteshjain1982]

may be you can try using DataGridViewTextBoxEditingControl, e.g

Private txtNumeric As DataGridViewTextBoxEditingControl
 
Private  Sub dataGridView1_EditingControlShowing(ByVal...)
    txtNumeric = CType(e.Control, DataGridViewTextBoxEditingControl)
    addhandler txtNumeric.TextChanged  addressof txtNumeric_TextChanged
End Sub
 
Private  Sub txtNumeric_TextChanged(ByVal...)
   if not IsNumeric(txtNumeric.Text)
         messagebox.show("Invalid data")
         txtNumeric.focus()
   End if
End Sub

[onlyGirl]

may be you can try using DataGridViewTextBoxEditingControl, e.g

Private txtNumeric As DataGridViewTextBoxEditingControl
 
Private  Sub dataGridView1_EditingControlShowing(ByVal...)
    txtNumeric = CType(e.Control, DataGridViewTextBoxEditingControl)
    addhandler txtNumeric.TextChanged  addressof txtNumeric_TextChanged
End Sub
 
Private  Sub txtNumeric_TextChanged(ByVal...)
   if not IsNumeric(txtNumeric.Text)
         messagebox.show("Invalid data")
         txtNumeric.focus()
   End if
End Sub

It says e is not declared.

[riteshjain1982]

came across This smaple hope it will help.

[onlyGirl]

Thanks!! I used a combination of GeekinOhio and riteshjain1982 example.

 Private Sub dgv_EditingControlShowing(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewEditingControlShowingEventArgs) Handles DataGridView1.EditingControlShowing
        If e.Control.GetType.ToString() = "System.Windows.Forms.DataGridViewTextBoxEditingControl" Then
            Dim c As DataGridViewTextBoxEditingControl = DirectCast(e.Control, DataGridViewTextBoxEditingControl)

            RemoveHandler c.TextChanged, AddressOf edtctrlOnTextChanged
            AddHandler c.TextChanged, AddressOf edtctrlOnTextChanged
        End If
        editingValue = e.Control.Text
    End Sub
    Private Sub edtctrlOnTextChanged(ByVal sender As Object, ByVal ea As EventArgs)
        Dim acceptable As String = "0123456789."
        Dim i As Integer
        Dim letter As String
        Dim errorCount As Integer = 0
        Dim ctrl As DataGridViewTextBoxEditingControl = DirectCast(sender, DataGridViewTextBoxEditingControl)
        For i = 0 To ctrl.Text.Length - 1
            letter = ctrl.Text.Chars(i)
            If InStr(acceptable, letter) = 0 Then
                errorCount = errorCount + 1
            End If
            If errorCount > 0 Then
                'MessageBox.Show("invalid characters")
                hasInvalidChar = True
            End If
        Next
    End Sub

    Private Sub DataGridView1_DataError(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewDataErrorEventArgs) Handles DataGridView1.DataError
        If hasInvalidChar = True Then
            MessageBox.Show("There are invalid characters in the field.  Please enter numeric values.", "ReservoirGrail", MessageBoxButtons.OK, MessageBoxIcon.Error)
        End If

    End Sub