Datagridview SelectedRows index error | Access and VB.NET

Question

I have an error in my software. My form contains a DataGridView connected with MS_access database.

When I click on a row in the DataGridView, I get this error:

Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index

My code:

Try
    If (DataGridView1.Rows.Count <= 0) Then Return
    FlatTextBox1.Text = String.Empty
    FlatTextBox2.Text = String.Empty
    FlatTextBox3.Text = String.Empty
    RichTextBox1.Text = String.Empty
    Dim indx As String = DataGridView1(1, DataGridView1.SelectedRows(0).Index).Value.ToString
    Dim dt As DataTable = New DBConnect().selectdata(String.Format("SELECT famille3.Article, famille3.quantité, famille3.prixch, famille3.prixvn, famille3.dateex, famille3.description FROM famille3 where famille3.ID = {0}  ", indx))
    If dt.Rows.Count > 0 Then
        FlatTextBox1.Text = dt.Rows(0)(0).ToString
        FlatTextBox2.Text = dt.Rows(0)(1).ToString
        FlatTextBox3.Text = dt.Rows(0)(2).ToString
        FlatTextBox9.Text = dt.Rows(0)(3).ToString
        FlatTextBox10.Text = (dt.Rows(0)(3).ToString - dt.Rows(0)(2).ToString) * dt.Rows(0)(1).ToString
        FlatTextBox11.Text = dt.Rows(0)(4).ToString
        RichTextBox1.Text = dt.Rows(0)(5).ToString
    End If
    dt.Dispose()
    dt = Nothing
Catch ex As Exception
    MessageBox.Show(ex.Message)
End Try

I think the stack is here

Dim indx As String = DataGridView1(1, DataGridView1.SelectedRows(0).Index).Value.ToString

How can I resolve it?

If you don't have any SelectedRows using the index zero will produce this error. — Steve, Nov 11 '16 at 13:35
look i use this code in cellclick event , and when i click on any cell i get this error :( — drx_072, Nov 11 '16 at 13:38
Clicking on a cell doesn't mean that you have selected a row. A row is selected when you click on the row header area and all the row is highlighted — Steve, Nov 11 '16 at 13:48
But in a CellClick event you have the _DataGridViewCellEventArgs_ parameter that contain the ColumnIndex and the RowIndex, so..... — Steve, Nov 11 '16 at 13:52

score 1 · Accepted Answer · edited May 23 '17 at 12:30

In a CellClick event of a DataGridView you receive a parameter of type DataGridViewCellEventArgs. This parameter contains the ColumnIndex and the RowIndex of the clicked cell. So getting the value of the column 1 of the clicked row is really simple as

Sub DataGridView1_CellClick(sender as Object,e As DataGridViewCellEventArgs)
    Dim indx As Integer = Convert.ToInt32(DataGridView1(1, e.RowIndex).Value)
    .....

Notice that I have applied a Convert.ToInt32 to the value of the first column. I assume that this is the numeric primary key to find your record. Remember that VB.NET allows you to freely convert string to numbers (VB6 compatibility) but in general this is considered a bad practice. Check your project properties and set Option Strict On instead and you will be forced to improve your code.

Another advice that I feel to give is to not write query in that way. This method is called sql string concatenation and it is the root of Sql Injection. (In your current case there is no big risk, but better to take good habits and always use parameterized queries)

@steve The next line `... where famille3.ID = {0} ", indx))` pretty much muddies up the int 32 either way. — djv, Nov 11 '16 at 14:00

Datagridview SelectedRows index error | Access and VB.NET

1 Answers1