DataRowState

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;

namespace DataRowState_Demo
{
    class Program
    {
        static void Main(string[] args)
        {
            DemonstrateRowState();
        }

        static private void DemonstrateRowState()
        {
            // 创建一个仅有一列的空表
            DataTable dataTable = new DataTable("dataTable");
            DataColumn dataColumn = new DataColumn("dataColumn");
            dataTable.Columns.Add(dataColumn);

            // 添加十行记录item 0,item 1,item 2,,item 9
            DataRow dataRow;
            for (int i = 0; i < 10; i++)
            {
                dataRow = dataTable.NewRow();
                dataRow["dataColumn"] = "item " + i;
                dataTable.Rows.Add(dataRow);
            }
            //标记接收数据变化
            dataTable.AcceptChanges();

            // 创建数据表视图
            DataView dataView = new DataView(dataTable);

            // 改变一个行值
            dataTable.Rows[1]["dataColumn"] = "Hello";

            // Add one row:
            dataRow = dataTable.NewRow();
            dataRow["dataColumn"] = "World";
            dataTable.Rows.Add(dataRow);

            // 设置行过滤，仅显示新增的和当前改变的
            dataView.RowStateFilter = DataViewRowState.Added
                | DataViewRowState.ModifiedCurrent;

            // 输出行为 "Hello" "World"
            PrintView(dataView, "ModifiedCurrent and Added");

            // 设置过滤显示被修改行的原始值
            dataView.RowStateFilter = DataViewRowState.ModifiedOriginal;
            PrintView(dataView, "ModifiedOriginal");

            // 删除3行
            dataTable.Rows[1].Delete();
            dataTable.Rows[2].Delete();
            dataTable.Rows[3].Delete();

            // 设置行过滤显示只显示和修改 
            dataView.RowStateFilter = DataViewRowState.Deleted;
            PrintView(dataView, "Deleted");

            //显示当前数据
            dataView.RowStateFilter = DataViewRowState.CurrentRows;
            PrintView(dataView, "Current");

            //显示没有改变的行
            dataView.RowStateFilter = DataViewRowState.Unchanged;
            PrintView(dataView, "Unchanged");

            //显示原始数据.
            dataView.RowStateFilter = DataViewRowState.OriginalRows;
            PrintView(dataView, "OriginalRows");
        }

        static private void PrintView(DataView dataView, string label)
        {
            Console.WriteLine(" " + label + "---------------");
            for (int i = 0; i < dataView.Count; i++)
            {
                Console.WriteLine(dataView[i]["dataColumn"]);
            }
        }
    }
}