Datatable和DataRow的使用

SqlConnection conn = new SqlConnection();     
    DataSet data = new DataSet();
    SqlDataAdapter da;
    String sqlStr;
    SqlCommandBuilder cb;
    protected void Page_Load(object sender, EventArgs e)
    {
        try
        {
            sqlStr = "select * from company";
            conn.ConnectionString = "server=(local);DataBase=contacters;uid=sa;pwd=zhuang";
            da = new SqlDataAdapter(sqlStr, conn);
            cb = new SqlCommandBuilder(da);
            da.Fill(data, "company");

            ViewCompany(data);
        }
        catch (Exception ex)
        {
            Response.Write(ex.Message.ToString());
        }

    }

    protected void Button1_Click(object sender, EventArgs e)
    {
       
        DataTable dt = data.Tables[0];
        DataRow dr1 = dt.NewRow();
        DataRow dr2 = dt.NewRow();

        //增加第一行
        dr1[0] = TextBox1.Text;
        dr1[1] = TextBox2.Text;
        dt.Rows.Add(dr1);
       
        //增加第二行
        dr2[0] = TextBox3.Text;
        dr2["name"] = TextBox4.Text;
        dt.Rows.Add(dr2);
 
        da.Update(dt);
 
        ViewCompany(data);

    }

    protected void Button2_Click(object sender, EventArgs e)
    {
 
       DataTable dt = data.Tables[0];
        DataRow dr1, dr2;

        //找到要修改的记录行
        for (int i = 0; i < dt.Rows.Count; i++)
        {
            if(dt.Rows[i][0].ToString()==TextBox1.Text)
            {
                dr1 = dt.Rows[i];
                dr1["name"] = TextBox2.Text;
            }

            if (dt.Rows[i][0].ToString() == TextBox2.Text)
            {
                dr2 = dt.Rows[i];
                dr2["name"] = TextBox4.Text;
            }
        }
        da.Update(dt);

        ViewCompany(data);

    }
    protected void Button3_Click(object sender, EventArgs e)
    {

        DataTable dt = data.Tables[0];

        //找到要删除的记录行
        for (int i = 0; i < dt.Rows.Count; i++)
        {
            if (dt.Rows[i][0].ToString() == TextBox1.Text || dt.Rows[i][0].ToString() == TextBox3.Text)
            {
                dt.Rows[i].Delete();
            }
           
        }

        da.Update(dt);

        ViewCompany(data);

    }

    protected void ViewCompany(DataSet data)
    {
        Label1.Text = "";

        //将 DataSet 的数据写入 Label
        for (int i = 0; i < data.Tables["company"].Rows.Count; i++)
        {

            Label1.Text += data.Tables["company"].Rows[i][0] + "    " + data.Tables["company"].Rows[i][1] + "<br>";
        }
      
    }