c#的dataset离线数据集示例

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Windows;using System.Windows.Controls;using System.Windows.Data;using System.Windows.Documents;using System.Windows.Input;using System.Windows.Media;using System.Windows.Media.Imaging;using System.Windows.Navigation;using System.Windows.Shapes;using System.Data.SqlClient;using System.Data; using System.Configuration;namespace _03.DataSet离线数据集{    /// <summary>    /// Window1.xaml 的交互逻辑    /// </summary>    public partial class Window1 : Window    {        public Window1()        {            InitializeComponent();        }        private void btnDS_Click(object sender, RoutedEventArgs e)        {            using (SqlConnection conn = new SqlConnection("Data Source=.;Initial Catalog=MyTest;User Id=sa;Password=123;"))            {                conn.Open();                using (SqlCommand cmd = conn.CreateCommand())                {                    cmd.CommandText = "select * from T_Student where age<@age";                    cmd.Parameters.Add(new SqlParameter("@age", 60));                    //cmd.ExecuteReader();并没有执行，而是new了一个adapter来接受cmd。                    //SqlDataAdapter是一个帮我们把SqlCommand的查询结果填充到DataSet中的类                    SqlDataAdapter adapter = new SqlDataAdapter(cmd);//SqlDataAdapter需要一个参数                    //DataSet相当于本地的一个复杂集合（List<int>）                    DataSet dataset = new DataSet();//DataSet是数据集                    adapter.Fill(dataset);//执行cmd并且把SqlCommand查询结果填充到DataSet                    //DataTable是内存中的数据表                    DataTable table = dataset.Tables[0];//因为数据库中就一个表T_Student，所以就是[0].                    DataRowCollection rows = table.Rows;//DataRowCollection是DataTable行的集合,这里的rows指查询结果的行                    for (int i = 0; i < rows.Count; i++)                    {                        DataRow row = rows[i];                        int age = (int)row["Age"];                        string name=(string)row["Name"];                        MessageBox.Show(name+","+age);                    }                }            }        }        private void btnDSS_Click(object sender, RoutedEventArgs e)        {            //采用ConfigurationManager.ConnectionStrings 属性,只能读取到app.config的配置信息。            string connStr = ConfigurationManager.ConnectionStrings["dbConnStr"].ConnectionString;            //项目根目录添加一个"应用程序配置文件",名字是App.config            //App.config加节点，给add起一个name            //项目添加对System.configuration的引用(理解为添加开发包,System.Data就是ADO.NET的开发包)            //就能使用System.configuration里的ConfigurationManager类            //asp.net里就变成了Web.config            MessageBox.Show(connStr);            using (SqlConnection conn = new SqlConnection(connStr))            {                conn.Open();                using (SqlCommand cmd = conn.CreateCommand())                {                    cmd.CommandText = "select * from T_Student where age<@age";                    cmd.Parameters.Add(new SqlParameter("@age",21));                    SqlDataAdapter adapter = new SqlDataAdapter(cmd);                    DataSet dataset = new DataSet();                    adapter.Fill(dataset);                    DataTable table=dataset.Tables[0];                    DataRowCollection rows = table.Rows;                    for(int i=0;i<rows.Count;i++)                    {                        DataRow row=rows[i];                        string hobbit=(string)row["Hobbit"];                        MessageBox.Show(hobbit);                    }                }            }        }    }}