CODEWITHSUNDEEP
vb.netdatagridviewerror-handling
stackexchange12
stackexchange12

Reputation: 652

How to prevent negative integers and blank inputs using DataError event in vb.net

I have a datagridview bound to a dataset. My goal for my datagridview is to prevent the user from entering negative integers and leaving the datagridviewcell blank. I wish to have some sort of error message or message-box to tell the user that their entry is invalid. Here is what I have so far, hopefully it can give you a starting point. I greatly appreciate any help or suggestions you may give. 

Private Sub DataGridView1_DataError(ByVal sender As Object, _
ByVal e As DataGridViewDataErrorEventArgs) _
Handles DataGridView1.DataError

    If  CInt(e.Exception.Message, "Input string was not in a correct format.") < 0 Then
        MessageBox.Show("Please Enter a positive Value")
        'This will change the number back to original
        DataGridView1.Rows(e.RowIndex).Cells(e.ColumnIndex).Value = " "
    End If

Upvotes: 0

Views: 3249

Answers (1)

Steven Liekens
Steven Liekens

Reputation: 14088

Have a look at the documentation for DataGridView's CellValidating event: http://msdn.microsoft.com/en-us/library/system.windows.forms.datagridview.cellvalidating.aspx

Attaching a handler for this event allows you to check whether the new value is:

  1. empty
  2. not a number
  3. a negative number

(in that order) and cancel the change if any one of those conditions are true.

EDIT

I'm not sure if this is a coincidence, but you can just copy and paste the example code from the documentation. It does exactly what you're trying to do.

Upvotes: 1

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