尝试.NET2.0客户端调用服务器端方法,但只能传字符串
aspx页面:
<%@ Page Language=”C#” AutoEventWireup=”true” CodeBehind=”Test.aspx.cs” Inherits=”AjaxTest.Test” %>
<%@ Implements Interface=”System.Web.UI.ICallbackEventHandler” %>
<!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>Untitled Page</title>
<style type=”text/css”>
.dg
{
color:blue;
}
</style>
</head>
<body>
<form id=”form1″ runat=”server”>
<asp:GridView ID=”GridView1″ runat=”server”>
<Columns>
<asp:CommandField ShowEditButton=”True” />
</Columns>
</asp:GridView>
<div>
Select a category:
<asp:DropDownList ID=”ddlCategory” runat=”server” DataSourceID=”SqlDataSource1″
DataTextField=”Name” DataValueField=”CategoryId” onChange=”GetSelectedProducts(this.value)” >
</asp:DropDownList><asp:SqlDataSource ID=”SqlDataSource1″ runat=”server” ConnectionString=”<%$ ConnectionStrings:MSPetShop4ConnectionString %>”
SelectCommand=”SELECT [Name], [CategoryId] FROM [Category]”></asp:SqlDataSource>
</div>
<asp:Label ID=”lblMsg” runat=”server” ></asp:Label>
<div>
</div>
Select a product:<br />
<div id=”MyDiv”></div>
<script language=”javascript” type=”text/javascript”>
function GetSelectedProducts(selectedValue)
{
CallServer(selectedValue,”);
}
function RecieveServerData(rValue)
{
document.getElementById(”MyDiv”).innerHTML = rValue;
}
</script>
</form>
</body>
</html>
———————————-
.CS页面:
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.IO;
using System.Data.SqlClient;
namespace AjaxTest
{
public partial class Test : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
string sbReference = ClientScript.GetCallbackEventReference(this, “arg”, “RecieveServerData”, “context”);
string cbScript = String.Empty;
// check if the script is already registered or not
if (!ClientScript.IsClientScriptBlockRegistered(”CallServer”))
{
cbScript = @” function CallServer(arg,context) { ” + sbReference + “}”;
ClientScript.RegisterClientScriptBlock(this.GetType(), “CallServer”, cbScript, true);
}
}
// protected variable
protected string returnValue;
public void RaiseCallbackEvent(string eventArgument)
{
if (!String.IsNullOrEmpty(eventArgument))
{
returnValue = eventArgument;
}
else
{
// Set a flag so that the GetCallbackResult is not called.
lblMsg.Text = “Faild.Because ” + eventArgument;
}
}
public string GetCallbackResult()
{
return GetProductsByCategoryID(returnValue);
}
private string GetProductsByCategoryID(string categoryID)
{
string connectionString = @”Data Source=GGZZHS-D030146;Initial Catalog=MSPetShop4;Integrated Security=True”;
SqlConnection myConnection = new SqlConnection(connectionString);
SqlCommand myCommand = new SqlCommand(”SELECT * FROM Product WHERE CategoryId = @CategoryId”, myConnection);
myCommand.Parameters.AddWithValue(”@CategoryId”, categoryID);
SqlDataAdapter ad = new SqlDataAdapter(myCommand);
DataSet ds = new DataSet();
ad.Fill(ds);
DataGrid dg = new DataGrid();
dg.ID = “dgProducts”;
dg.DataSource = ds;
dg.DataKeyField = “ProductId”;
dg.CssClass = “dg”;
dg.DataBind();
StringWriter sw = new StringWriter();
HtmlTextWriter htw = new HtmlTextWriter(sw);
dg.RenderControl(htw);
return sw.ToString();
//DropDownList ddlProducts = new DropDownList();
//ddlCategory.ID = “ddlProducts”;
//ddlProducts.DataSource = ds;
////ddlProducts.Attributes.Add(”onChange”, “PopSelectedProductID(this.value)”);
//ddlProducts.DataTextField = “Name”;
//ddlProducts.DataValueField = “ProductId”;
//ddlProducts.DataBind();
//StringWriter sw = new StringWriter();
//HtmlTextWriter htw = new HtmlTextWriter(sw);
//ddlProducts.RenderControl(htw);
//return sw.ToString();
}
}
}