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);                     }                 }             }         }     } }