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.ASPx:
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.ASPx.cs" Inherits="_Default" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title>無標題頁</title> <script type="text/Javascript"> //向服務器傳遞參數 function DoSearch(){ var firstName=document.getElementById("TextBox1").value; CallServer(firstName,""); } //得到服務器的數據 function ReceiveServerData(txtUserInfo){ Results.innerHTML=txtUserInfo; } //設置每1秒執行一次 setInterval("DoSearch()",1000); </script> </head> <body> <form id="form1" runat="server"> <div> 姓名:<ASP:TextBox ID="TextBox1" runat="server"></ASP:TextBox> <br /> <span id="Results" style=" width:500px;"></span> </div> </form> </body> </html>[/code].ASPx.cs[code]using System; using System.Collections; using System.Configuration; using System.Data; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Data.SqlClient; public partial class _Default : System.Web.UI.Page, ICallbackEventHandler { protected string txtUserInfo; protected void Page_Load(object sender, EventArgs e) { //獲取一個對客戶端函數的引用 string cbReference = Page.ClientScript.GetCallbackEventReference(this, "arg", "ReceiveServerData", "context"); //動態注冊回調函數 string callbackScript = "function CallServer(arg,context)" + "{" + cbReference + "};"; //引發callbackScript Page.ClientScript.RegisterStartupScript(this.GetType(), "CallServer", callbackScript, true); } //引發Callback事件處理 public void RaiseCallbackEvent(string txtFirstName) { if (txtFirstName != null) { String connString = System.Configuration.ConfigurationManager.ConnectionStrings["sqlserver2008"].ToString(); SqlConnection conn = new SqlConnection(connString); conn.Open(); SqlCommand comm = new SqlCommand("select * from zzx where [name]=@name", conn); comm.Parameters.Add("@name", SqlDbType.VarChar).Value = txtFirstName; SqlDataReader reader = comm.ExecuteReader(CommandBehavior.CloseConnection); if (reader.Read()) { txtUserInfo = "員工編號:" + reader["id"].ToString() + "<br>"; txtUserInfo += "員工姓名:" + reader["name"].ToString() + "<br>"; txtUserInfo += "地址:" + reader["address"].ToString() + "<br>"; txtUserInfo += "服務器查詢時間:" + DateTime.Now.ToString(); } else { if (string.IsNullOrEmpty(txtFirstName)) { txtUserInfo = "請輸入姓名"; } else { txtUserInfo = "查無此人"; } } comm.Dispose(); reader.Dispose(); conn.Dispose(); } } //得到回調的結果,返回給客戶端 public string GetCallbackResult() { return txtUserInfo; } }
簡化版(偷懶一下):
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.ASPx.cs" Inherits="_Default" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title>無標題頁</title> <script type="text/Javascript"> function OnCallBack(txtUserInfo,context){ Results.innerHTML=txtUserInfo; } </script> </head> <body> <form id="form1" runat="server"> <div> 姓名:<ASP:TextBox ID="TextBox1" runat="server"></ASP:TextBox> <input id="Button2" type="button" value="button" onclick="<%=Page.ClientScript.GetCallbackEventReference(this, "document.getElementById('TextBox1').value", "OnCallBack",null)%>" /> <br /> <span id="Results" style="pink; width: 500;"></span> </div> </form> </body> </html>.ASPx.csusing System; using System.Collections; using System.Configuration; using System.Data; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Data.SqlClient; using System.Text; public partial class _Default : System.Web.UI.Page, ICallbackEventHandler { protected StringBuilder txtUserInfo; protected void Page_Load(object sender, EventArgs e) { } public string GetCallbackResult() { return txtUserInfo.ToString(); } public void RaiseCallbackEvent(string txtFirstName) { txtUserInfo = new StringBuilder(); String connString = ConfigurationManager.ConnectionStrings["sqlserver2008"].ToString(); SqlConnection conn = new SqlConnection(connString); conn.Open(); SqlCommand comm = new SqlCommand("select * from zzx where [name]=@name", conn); comm.Parameters.Add("@name", SqlDbType.VarChar).Value = txtFirstName; SqlDataReader reader = comm.ExecuteReader(CommandBehavior.CloseConnection); if (reader.Read()) { txtUserInfo.Append("員工編號:" + reader["id"].ToString() + "<br>"); txtUserInfo.Append("員工姓名:" + reader["name"].ToString() + "<br>"); txtUserInfo.Append("地址:" + reader["address"].ToString() + "<br>"); txtUserInfo.Append("查詢時間:" + DateTime.Now.ToString()); } else { if (txtFirstName == string.Empty) { txtUserInfo.Append("請輸入姓名"); } else { txtUserInfo.Append("查無此人"); } reader.Dispose(); comm.Dispose(); conn.Dispose(); }} }
示例3:
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default3.ASPx.cs" Inherits="Default3" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title>無標題頁</title> <script type="text/Javascript"> //客戶端執行的方法 //下面的方法是接收并處理服務器方法返回的結果 function Success(args,context){ message.innerHTML=args; } //下面的方式是當接收服務器方法處理的結果發生異常時調用的方法 function Error(){ message.innerHTML="發生了異常!"; } </script> </head> <body> <form id="form1" runat="server"> <div> 用戶名:<input type="text" id="txtUserName" onblur="CallServerMethod(txtUserName.value,null)" /> <span id="message"></span> <br /> 密碼:<input type="password" size="10" maxlength="20" id="txtPwd" /> </div> </form> </body> </html>[code]public partial class Default3 : System.Web.UI.Page,ICallbackEventHandler //實現ICallbackEventHandler接口 { String result = String.Empty; protected void Page_Load(object sender, EventArgs e) { //獲取當前頁的ClientScriptManager的引用 ClientScriptManager csm = Page.ClientScript; /*獲取回調的引用.會在客戶端生成WebForm_DoCallback方法, * 調用它來達到異步調用.這個方法是微軟寫的方法,會被發送 到客戶端*/ /*注意這里的"Success"和Error兩個字符串分別是客戶端代碼中 *定義的兩個Javascript函數*/ //下面的方法最后一個參數的意義:true表示執行異步回調,false標志執行同步回調 String reference = csm.GetCallbackEventReference(this, "args", "Success", "", "Error", true); String callbackScript = "function CallServerMethod(args,context){/n"+ reference+";/n }"; //向當前頁面注冊Javascript腳本代碼 csm.RegisterClientScriptBlock(this.GetType(), "CallServerMethod",callbackScript,true); } #region ICallbackEventHandler 成員 /// <summary> /// 返回回調方法執行結果的方法 /// </summary> public string GetCallbackResult() { return result; } /// <summary> /// 在服務器端運行回調方法 /// </summary> public void RaiseCallbackEvent(string eventArgument) { if (eventArgument.ToLower().IndexOf("admin")!=-1) { result =eventArgument+ "不能作為用戶注冊."; } else { result = eventArgument + "可以注冊."; } } #endregion }
AspNet技術：Asp.net回調技術Callback學習筆記，轉載需保留來源！
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