Change DefaultCellStyle when using a DataTable in Datagridview

Question

*Using Powershell studio but I could work with a C# answer since it's mostly the same except for syntax.

Here is the context:

I was previously using:

$datagridviewInfo.Rows.Add("123", "456")

To populate a DataGridView, but I noticed afterwards I couldn't export the DataGridView to CSV if it didn't use a "DataTable" as it's DataSource.

So now i'm creating a DataTable and adding my rows to this object. I can now export sucessfully to CSV. HOWEVER, I can't manage to style my cells like I was able to before. If I do this to test :

$button1_Click={
 $RowNomPoste = $datagridviewInfo.Rows.Add("Poste", "$poste est inaccessible.")
 $datagridviewInfo.Rows.Item($RowNomPoste).DefaultCellStyle.BackColor = "Red"
}

It works and gives me that row highlighted in red. However that method isn't using a DataTable so it's no good since later on I can't export to CSV.

Now if I try this :

$button2_Click={
 $tableInfoPoste = New-Object system.Data.DataTable "TableInfoPoste"

 $tableInfoPoste.Columns.Add("Propriété")
 $tableInfoPoste.Columns.Add("Valeur")

 $datagridviewInfo.DataSource = $tableInfoPoste

 $RowNomPoste = $tableInfoPoste.Rows.Add("Poste", "$poste est inaccessible.")

 $tableInfoPoste.Rows.Item($RowNomPoste).DefaultCellStyle.BackColor = "Red"

}

It adds the row but won't allow me to change it's DefaultCellStyle. It throws the error :

 Cannont convert argument «index» («System.Data.DataRow»)  «get_Item» to type «System.Int32»: «
ERROR: Cannot convert the value «System.Data.DataRow» of type «System.Data.DataRow» to type «System.Int32».»»

Why is it working when using the first method of adding rows directly to DataGridView but NOT when using a DataTable? How can I use a DataTable but still style my row properly?

Much appreciated.

That is because using a DataTable, the `$RowNomPoste = $tableInfoPoste.Rows.Add("Poste", "$poste est inaccessible.")` now returns an object of type `System.Data.DataRow` which is not an Int32 index value. Try something like `($tableInfoPoste.Rows | Where-Object { $_.Cells[1].Value -like '*inaccessible.' } | ForEach-Object { $_.DefaultCellStyle.BackColor = "Red" }` — Theo, Nov 19 '18 at 16:08
That seems like good code, but strangely it complains $_.Cells is Null even though the row is clearly Added in the code before it? (Cannot index into a null array) — Rakha, Nov 19 '18 at 16:48
Ah.. That should have been `$datagridviewInfo.Rows | Where-Object {...}` of course.. — Theo, Nov 19 '18 at 21:03

score 0 · Accepted Answer · answered Nov 19 '18 at 18:39

I got it working with the RowPrePaint event like this :

$datagridviewInfo_RowPrePaint=[System.Windows.Forms.DataGridViewRowPrePaintEventHandler]{
 if (($datagridviewInfo.Rows[$_.RowIndex].Cells[1].Value) -like "*inaccessible*")
 {
  $datagridviewInfo.Rows[$_.RowIndex].DefaultCellStyle.BackColor = 'red'
 }


}

All thanks to jrv at Technet :

https://social.technet.microsoft.com/Forums/windowsserver/en-US/6cb6a5be-08bd-47d4-8783-66d57fc26ead/change-defaultcellstyle-when-using-a-datatable-in-datagridview?forum=winserverpowershell

Change DefaultCellStyle when using a DataTable in Datagridview

1 Answers1