Asp.net回调技术Callback学习笔记_

1、A回调技术Callback学习笔记_ .aspx: 001 % Page Language=C# AutoEventWireup=true CodeFile=Default.aspx.cs Inherits=_Default % 002 003 !DOCTYPE html PUBLIC -/W3C/DTD XHTML 1.0 Transitional/EN l1/DTD/xhtml1-transitional.dtd 004 html xmlns=l 005 head runat=server 006 title无标题页/title 007 008 script type=text/javas

2、cript 009 010 /向服务器传递参数 011 function DoSearch() 012 var firstName=document.getElementById(TextBox1).value; 013 CallServer(firstName,); 014 015 016 /得到服务器的数据 017 function ReceiveServerData(txtUserInfo) 018 Results.innerHTML=txtUserInfo; 019 020 021 /设置每1秒执行一次 022 setInterval(DoSearch(),1000); 023 /sc

3、ript 024 025 /head 026 body 027 form id=form1 runat=server 028 div 029 姓名:asp:TextBox ID=TextBox1 runat=server/asp:TextBox 030 br / 031 span id=Results style= width:500px;/span 032 /div 033 /form 034 /body 035 /html 036 /code 037 .aspx.cs 038 code 039 using System; 040 using System.Collections; 041

4、using System.Configuration; 042 using System.Data; 043 using System.Web; 044 using System.Web.Security; 045 using System.Web.UI; 046 using System.Web.UI.HtmlControls; 047 using System.Web.UI.WebControls; 048 using System.Web.UI.WebControls.WebParts; 049 using System.Data.SqlClient; 050 051 public pa

5、rtial class _Default : System.Web.UI.Page, ICallbackEventHandler 052 053 protected string txtUserInfo; 054 055 056 protected void Page_Load(object sender, EventArgs e) 057 058 /猎取一个对客户端函数的引用 059 string cbReference = Page.ClientScript.GetCallbackEventReference(this, arg, ReceiveServerData, context);

6、060 /动态注册回调函数 061 string callbackScript = function CallServer(arg,context) + + cbReference + ; 062 /引发callbackScript 063 Page.ClientScript.RegisterStartupScript(this.GetType(), CallServer, callbackScript, true); 064 065 066 /引发Callback大事处理 067 public void RaiseCallbackEvent(string txtFirstName) 068

7、069 if (txtFirstName != null) 070 071 String connString = System.Configuration.ConfigurationManager.ConnectionStringssqlserver2021.ToString(); 072 073 SqlConnection conn = new SqlConnection(connString); 074 075 conn.Open(); 076 077 SqlCommand comm = new SqlCommand(select * from zzx where name=name,

8、conn); 078 079 comm.Parameters.Add(name, SqlDbType.VarChar).Value = txtFirstName; 080 081 SqlDataReader reader = comm.ExecuteReader(CommandBehavior.CloseConnection); 082 if (reader.Read() 083 084 txtUserInfo = 员工编号: + readerid.ToString() + br; 085 txtUserInfo += 员工姓名: + readername.ToString() + br; 0

9、86 txtUserInfo += 地址: + readeraddress.ToString() + br; 087 txtUserInfo += 服务器查询时间: + DateTime.Now.ToString(); 088 089 else 090 091 if (string.IsNullOrEmpty(txtFirstName) 092 093 txtUserInfo = 请输入姓名; 094 095 else 096 097 txtUserInfo = 查无此人; 098 099 100 101 comm.Dispose(); 102 reader.Dispose(); 103 co

10、nn.Dispose(); 104 105 106 107 /得到回调的结果,返回给客户端 108 public string GetCallbackResult() 109 110 return txtUserInfo; 111 112 113 114 简化版(偷懒一下): 01 % Page Language=C# AutoEventWireup=true CodeFile=Default.aspx.cs Inherits=_Default % 02 03 !DOCTYPE html PUBLIC -/W3C/DTD XHTML 1.0 Transitional/EN l1/DTD/xht

11、ml1-transitional.dtd 04 html xmlns=l 05 head runat=server 06 title无标题页/title 07 08 script type=text/javascript 09 function OnCallBack(txtUserInfo,context) 10 Results.innerHTML=txtUserInfo; 11 12 /script 13 14 /head 15 body 16 form id=form1 runat=server 17 div 18 姓名:asp:TextBox ID=TextBox1 runat=serv

12、er/asp:TextBox 19 input id=Button2 type=button value=button 20 onclick=%=Page.ClientScript.GetCallbackEventReference(this, document.getElementById(TextBox1).value, OnCallBack,null)% / 21 br / 22 span id=Results style=pink; width: 500;/span 23 /div 24 /form 25 /body 26 /html 27 .aspx.cs 28 29 using S

13、ystem; 30 using System.Collections; 31 using System.Configuration; 32 using System.Data; 33 using System.Web; 34 using System.Web.Security; 35 using System.Web.UI; 36 using System.Web.UI.HtmlControls; 37 using System.Web.UI.WebControls; 38 using System.Web.UI.WebControls.WebParts; 39 using System.Da

14、ta.SqlClient; 40 using System.Text; 41 public partial class _Default : System.Web.UI.Page, ICallbackEventHandler 42 43 protected StringBuilder txtUserInfo; 44 45 protected void Page_Load(object sender, EventArgs e) 46 47 48 49 50 public string GetCallbackResult() 51 52 return txtUserInfo.ToString();

15、 53 54 55 public void RaiseCallbackEvent(string txtFirstName) 56 57 txtUserInfo = new StringBuilder(); 58 String connString = ConfigurationManager.ConnectionStringssqlserver2021.ToString(); 59 SqlConnection conn = new SqlConnection(connString); 60 conn.Open(); 61 SqlCommand comm = new SqlCommand(sel

16、ect * from zzx where name=name, conn); 62 comm.Parameters.Add(name, SqlDbType.VarChar).Value = txtFirstName; 63 SqlDataReader reader = comm.ExecuteReader(CommandBehavior.CloseConnection); 64 if (reader.Read() 65 66 txtUserInfo.Append(员工编号: + readerid.ToString() + br); 67 txtUserInfo.Append(员工姓名: + r

17、eadername.ToString() + br); 68 txtUserInfo.Append(地址: + readeraddress.ToString() + br); 69 txtUserInfo.Append(查询时间: + DateTime.Now.ToString(); 70 71 else 72 73 if (txtFirstName = string.Empty) 74 75 txtUserInfo.Append(请输入姓名); 76 77 else 78 79 txtUserInfo.Append(查无此人); 80 81 reader.Dispose(); 82 comm

18、.Dispose(); 83 conn.Dispose(); 84 85 86 示例3: 01 % Page Language=C# AutoEventWireup=true CodeFile=Default3.aspx.cs Inherits=Default3 % 02 03 !DOCTYPE html PUBLIC -/W3C/DTD XHTML 1.0 Transitional/EN l1/DTD/xhtml1-transitional.dtd 04 05 html xmlns=l 06 head runat=server 07 title无标题页/title 08 script typ

19、e=text/javascript 09 /客户端执行的方法 10 /下面的方法是接收并处理服务器方法返回的结果 11 function Success(args,context) 12 message.innerHTML=args; 13 14 15 /下面的方式是当接收服务器方法处理的结果发生特别时调用的方法 16 function Error() 17 message.innerHTML=发生了特别!; 18 19 /script 20 /head 21 body 22 form id=form1 runat=server 23 div 24 用户名:input type=text id

20、=txtUserName onblur=CallServerMethod(txtUserName.value,null) / 25 span id=message/span 26 br / 27 密码:input type=password size=10 maxlength=20 id=txtPwd / 28 /div 29 /form 30 /body 31 /html 32 code 33 public partial class Default3 : System.Web.UI.Page,ICallbackEventHandler /实现ICallbackEventHandler接口

21、34 35 36 String result = String.Empty; 37 38 protected void Page_Load(object sender, EventArgs e) 39 40 /猎取当前页的ClientScriptManager的引用 41 ClientScriptManager csm = Page.ClientScript; 42 /*猎取回调的引用.会在客户端生成WebForm_DoCallback方法, 43 * 调用它来达到异步调用.这个方法是微软写的方法,会被发送 44 到客户端*/ 45 /*留意这里的Success和Error两个字符串分别是客户端代码中 46 *定义的两个javascript函数*/ 47 /下面的方法最终一个参数的意义:true表示执行异步回调,false标记执行同步回调 48 String reference