private void grdData_CellMouseEnter(object sender, DataGridViewCellEventArgs e) { if (e.RowIndex < 0 || e.ColumnIndex < 0) { return; } this.toolTip.Hide(this.grdData); if (e.ColumnIndex >= 0 && e.RowIndex >= 0) { DataGridViewRow row = grdData.Rows[e.RowIndex]; string strCellToolTipText = DataGridViewHelper.GetDataRowInfo(grdData, row); this.toolTip.Show(strCellToolTipText, this.grdData); } }