掌握TreeView用法(7)

 
SQLhelper 类
 1 using System.Data;
 2 using System.Data.SqlClient;
 3 using System.Configuration;
 4
 5 namespace DataTreeDAL
 6 {
 7     class sqlHelper
 8     {
 9         protected static readonly string conStr = ConfigurationManager.ConnectionStrings["conStr"].ConnectionString;
10         //返回一个结果集
11         public static DataTable GetDatatable(string sql,params SqlParameter[] Paramers)
12         {
13             using (SqlConnection con = new SqlConnection(conStr))//创建一个连接
14             {
15                 con.Open();//打开连接通道
16                 using (SqlCommand cmd =con.CreateCommand())//创建一个命令对象
17                 {
18                     cmd.CommandText = sql;
19                     cmd.Parameters.AddRange(Paramers);
20                     SqlDataAdapter da = new SqlDataAdapter(cmd);
21                     DataTable dt = new DataTable();
22                     da.Fill(dt);
23                     return dt;
24                 }
25             }
26         }
27