ADO.NET中异步处理的方式——函数回调方式

函数回调方式

 用代码说明

在页面上放Gridview用于显示

 
   
  < 
  body 
  > 
  
     
  < 
  form  
  id 
  ="form1" 
   runat 
  ="server" 
  > 
  
     
  < 
  div 
  > 
  
         
  < 
  asp:GridView  
  ID 
  ="gvData" 
   runat 
  ="server" 
  > 
  
         
  </ 
  asp:GridView 
  > 
  
     
  </ 
  div 
  > 
  
     
  </ 
  form 
  > 
  
 
  </ 
  body 
  > 
 

 

 

使用函数回调法方式取出数据

 

 
   
  using 
   System.Data;
 
  using 
   System.Data.SqlClient;
 
  using 
   System.Configuration;

 
  namespace 
   AdoAsyncDB
{
     
  /// 
    
  <summary> 
  
     
  /// 
   函数回调法 
     
  /// 
    
  </summary> 
  
 
       
  public 
    
  partial 
    
  class 
   CallBackMehtod : System.Web.UI.Page
    {
 
           
  protected 
    
  void 
   Page_Load( 
  object 
   sender, EventArgs e)
        {
            GetCallBackData();
        }

         
  private 
    
  void 
   GetCallBackData()
        {
            SqlConnection DBCon;
            SqlCommand Command  
  = 
    
  new 
   SqlCommand();
            IAsyncResult AsyncResult;

            DBCon  
  = 
    
  new 
   SqlConnection();
            DBCon.ConnectionString  
  = 
   ConfigurationManager.ConnectionStrings[ 
  " 
  NorthWindDB 
  " 
  ].ConnectionString;
            Command.CommandText  
  = 
    
  @" 
  select top 20 companyName,contactName,city,postalCode from dbo.Customers 
  " 
  ;
            Command.CommandType  
  = 
   CommandType.Text;
            Command.Connection  
  = 
   DBCon;
            DBCon.Open();
            AsyncResult  
  = Command.BeginExecuteReader(new 
   AsyncCallback(CallBackMethod), Command);
            System.Threading.Thread.Sleep( 
  1000 
  );
            DBCon.Close();
        }

         
  public void CallBackMethod(IAsyncResult IResult)
        {
            SqlCommand Command = (SqlCommand)IResult.AsyncState;
            SqlDataReader OrdersReader = Command.EndExecuteReader(IResult);
            gvData.DataSource = 
   OrdersReader;
            gvData.DataBind();
        }
    }
} 
 

 

代码下载：AdoAsyncDB.rar

 

文章汇总：

ADO.NET中异步处理的方式——Poll方式

ADO.NET中异步处理的方式——Wait方式

ADO.NET中异步处理的方式——函数回调方式