DataGrid更新

Question

我有这个方法来更新我的数据库。我想从表中选择一些单元格并更新它，例如我想更改单元格（ID [1]，Name [Peter]，LastName [Holg]）------＆gt; [ID [2 ]，名称[Rob]，LastName [Clein]）但我不知道如何在datagrids中选择它们。

表：ID_Customer / Name / Lastname

public void Customer()
    {
        DataTable update = new DataTable("Customer");
        update.Columns.Add("ID_Customer");
        update.Columns.Add("Name");
        update.Columns.Add("LastName");

        Cust_Map customer= new Cust_Map();

        Customer customer1= new Customer ();
        customer1.ID_Customer = Convert.ToInt32(dataGridView1.Rows[dataGridView1.RowCount - 2].Cells[0].Value);
        customer1.Name = Convert.ToString(dataGridView1.Rows[dataGridView1.RowCount - 2].Cells[1].Value);
        customer1.LastName = Convert.ToString(dataGridView1.Rows[dataGridView1.RowCount - 2].Cells[2].Value);


        update.Rows.Add(customer1.ID_Customer, customer1.Name, customer1.LastName);
        customer.Update(customer1.ID_Customer, customer1.Name, customer1.LastName);

    }