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if (textBox1.Text != "")
            {
                for (int i = 0; i < dataGridView1.ColumnCount; i++)
                {
                    for (int j = 0; j < dataGridView1.RowCount-1; j++)
                    {
                        dataGridView1.Rows[j].Cells[i].Style.BackColor = Color.White;
                        dataGridView1.Rows[j].Cells[i].Style.ForeColor = Color.Black;
                    }
                }

                for (int i = 0; i < dataGridView1.Columns.Count; i++)
                {
                    for (int j = 0; j < dataGridView1.Rows.Count-1; j++)
                    {
                        if (dataGridView1.Rows[j].Cells[i].Value.ToString().Contains(textBox1.Text))
                        {
                            dataGridView1.Rows[j].Cells[i].Style.BackColor = Color.AliceBlue;
                            dataGridView1.Rows[j].Cells[i].Style.ForeColor = Color.Blue;
                        }
                    }
                }
            }