Ric,

>Is there any point in using the .NET Error Provider to display broken rules within a (Winforms) datagrid?
>
>I've tried it, and the little error icon appears in the correct column, but always in the first row, even if the error is related to some other row.
>
>This is a basic header-detail form, with an Order shown at the top of the form, and a DataGrid of OrderLines shown at the bottom of the form.

If you specify the row number in which the error occurs within your rule object, then the error icon appears next to the correct row. For example, in the following code, as each OrderDetail row is processed, the current row number is stored in the business rule object's CurrentRow property. MM .NET picks up this value and passes it along to the error provider which displays the error icon in the appropriate row:

public override bool CheckRulesHook(DataSet ds, string tableName)
{
	bool result = true;
	int RowCount = ds.Tables[tableName].Rows.Count;
	for (int row=0; row<RowCount; row++)
	{
		this.DataRow = ds.Tables[tableName].Rows[row];
		this.CurrentRow = row;

		if (this.DataRow["Quantity"] is Int16)
		{
			this.ValidateQuantity((System.Int16)this.DataRow["Quantity"]);
		}
		else
		{
			this.ValidateQuantity((int)this.DataRow["Quantity"]);
		}
		this.ValidateProductID((int)this.DataRow["ProductID"]);
	}
	return result;
}

Regards,