（lha整理重要 c#表处理-2）c#datatable用法（手工写入数据）

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication5
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            //winform初始化

            InitializeComponent();
            //建表
            DataTable dt = new DataTable();
            //定义列名
            dt.Columns.Add("a", typeof(string));
            dt.Columns.Add("b", typeof(string));
            dt.Columns.Add("c", typeof(string));
            //给表加行
            for (int i = 0; i < 4; i++)
            {
                    dt.Rows.Add("a" + i, "b" + i, "c" + i);
            }
            //再定义一个表
            DataTable dt01 = new DataTable();
            //定义和dt一样的结构
            dt01 = dt.Clone();
            //对dt表筛选
            DataRow[] dr = dt.Select("a = 'a2'");
            //newdt加入行数据
            for (int i = 0; i < dr.Length; i++)
            {
                dt01.ImportRow((DataRow)dr[i]);
            }
            //再向dt加入数据
            for (int i = 0; i < 2; i++)
            {
                dt.Rows.Add("a" + i, "b" + i, "c" + i);
            }
            //copy是完全拷贝过来，包括数据结构
            DataTable dt00 = new DataTable();
            dt00 = dt.Copy();
            // 对dt00的数据直接修改
            dt00.Rows[0][0] = "i";
            dt00.Rows[1][0] = "ii";
            dt00.Rows[2][1] = " i am ";
            // 对dt00的数据遍历修改
            for (int i = 0; i < dt00.Rows.Count; i++)
            {
                dt00.Rows[i][2] = "ok" + i;
            }
            dataGridView1.DataSource = dt;
            dataGridView2.DataSource = dt01;
            dataGridView3.DataSource = dt00;
        }

      
    }
}