c# เชคและแจ้งเตือนถ้าข้อมูลที่ใส่ไม่ไช่ตัวเลขใน DataGridView

 object test = dataGridView1.Rows[j].Cells[10].Value;
                       
                        
                        if(test.GetType()==typeof(string))
                        {
                            MessageBox.Show("Please fill in : Input Number Not A-Z /@*-+ in Row ", "Result", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                            return;
                        }

int n;
            for (int j = 0; j <= dataGridView1.RowCount - 1; j++)
            {
                if (!dataGridView1.Rows[j].IsNewRow)
                {
                    if (!int.TryParse(dataGridView1.Rows[j].Cells[10].Value.ToString(), out n))
                    {
                        MessageBox.Show("Please fill in : Input Unit Num in Row ", "Result", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                        return;
                    }
                }
            }

 if (!int.TryParse(dataGridView1.Rows[i].Cells[10].Value.ToString(), out n))