如何在datatable中编辑Column的Row Value

Question

我有public static DataTable GetTable()我还使用以下方法获取了我的数据表的值

DataTable table = new DataTable();
table = GetTable();
string expression;
expression = "B.Id = " + textBox1.Text;
DataRow[] foundRows;
foundRows = table.Select(expression);
for (int i = 0; i < foundRows.Length; i++)
{

    sno.Text = foundRows[i][1].ToString();
    name.Text = foundRows[i][2].ToString();
    dcn.Text = foundRows[i][3].ToString();
    stat.Text = foundRows[i][4].ToString();
}

那么如何更改目前使用以下代码的foundRows [i] [4]的值

DataTable table = new DataTable();
        table = GetTable();
        string expression;
        expression = "B.Id = "+textBox1.Text;
        DataRow[] foundRows;
        foundRows = table.Select(expression);
        for(int i = 0; i < foundRows.Length; i ++)
        {
         if(button1.Text == "Make Preasent!")
         {
             foundRows[i].SetField(4, true);
            table.AcceptChanges();
         }
         else
         {
             foundRows[i].SetField(4, false);
             table.AcceptChanges();
         }
        }

但它不会改变值 这是`timer.OnTick（）

if (textBox1.TextLength < 9 || textBox1.TextLength > 9)
            {
                sno.Text = "";
                name.Text = "";
                dcn.Text = "";
                stat.Text = "";
                button1.Text = "";
            }

            try
            {
                //textBox1.Text = textBox1.Text.Replace("ONE", "1");
                //textBox1.Text = textBox1.Text.Replace("g", "");

                table = GetTable();              
                expression = "B.Id = " + textBox1.Text;
                foundRows = table.Select(expression);
                for (int i = 0; i < foundRows.Length; i++)
                {

                    if(textBox1.TextLength ==9)
                    {
                    sno.Text = foundRows[i][1].ToString();
                    name.Text = foundRows[i][2].ToString();
                    dcn.Text = foundRows[i][3].ToString();
                    stat.Text = foundRows[i][4].ToString();
                    if (foundRows[i][4].ToString()==true.ToString())
                    {
                        button1.Text = "Already Preasent!";

                    }
                    else if (foundRows[i][4].ToString() == false.ToString())
                    {
                        button1.Text = "Make Preasent!";
                    }
                    }

                }
            }
            catch (Exception es)
            {
                if(textBox1.TextLength< 9)
                {

                }
                else
                {
                   // MessageBox.Show(es.Message);
                }
            }

`