DataGridViewでErrorアイコンを表示する方法

DataGridViewでErrorアイコンを表示する方法
VB.NET

dgv1(0, 0).ErrorText = "セルエラー発生"
dgv1.Rows(3).ErrorText = "行エラー発生"

C#

dgv1[0, 0].ErrorText = "セルエラー発生";
dgv1.Rows[3].ErrorText = "行エラー発生";

CellErrorTextNeededイベントまたはRowErrorTextNeededイベントを活用する方法
VB.NET

Private Sub dgv1_CellErrorTextNeeded(ByVal sender As Object, _
        ByVal e As DataGridViewCellErrorTextNeededEventArgs) _
        Handles dgv1.CellErrorTextNeeded
    Dim dgv As DataGridView = CType(sender, DataGridView)
    Dim cellVal As Object = dgv(e.ColumnIndex, e.RowIndex).Value
    If TypeOf cellVal Is Integer AndAlso CInt(cellVal) < 0 Then
        e.ErrorText = "０以上で入力してください"
    End If
End Sub

Private Sub dgv1_RowErrorTextNeeded(ByVal sender As Object, _
        ByVal e As DataGridViewRowErrorTextNeededEventArgs) _
        Handles dgv1.RowErrorTextNeeded
    Dim dgv As DataGridView = CType(sender, DataGridView)
    If dgv("col1", e.RowIndex).Value Is DBNull.Value AndAlso _
        dgv("col2", e.RowIndex).Value Is DBNull.Value Then
        e.ErrorText = _
            "少なくともcol1とcol2の一方は必須です"
    End If
End Sub

C#

private void dgv1_CellErrorTextNeeded(object sender,
    DataGridViewCellErrorTextNeededEventArgs e)
{
    DataGridView dgv = (DataGridView)sender;
    object cellVal = dgv[e.ColumnIndex, e.RowIndex].Value;
    if (cellVal is int && ((int)cellVal) < 0)
    {
        e.ErrorText = "０以上で入力してください";
    }
}

private void dgv1_RowErrorTextNeeded(object sender,
    DataGridViewRowErrorTextNeededEventArgs e)
{
    DataGridView dgv = (DataGridView)sender;
    if (dgv["col1", e.RowIndex].Value == DBNull.Value &&
        dgv["Column2", e.RowIndex].Value == DBNull.Value)
    {
        e.ErrorText = 
            "少なくともcol1とcol2の一方は必須です";
    }
}