javascript 调用后台方法

来源：互联网发布：vip后缀域名备案问题编辑：程序博客网时间：2024/05/16 11:39

来自：http://blog.csdn.net/hellojimmy520/article/details/7242725

方法一：直接使用<%=%>调用

前台JS：

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<script type="text/javascript">
var methodStr = "<%=BehindMethod() %>";
alert(methodStr);
</script>

 <script type="text/javascript">        var methodStr = "<%=BehindMethod() %>";        alert(methodStr);        </script>

后头方法：

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public staticstring BehindMethod()
{
return "这是一个后台的方法";
}

public static string BehindMethod()        {            return "这是一个后台的方法";        }

方法二：用ajax调用

前台js:

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<script type="text/javascript" src="js/jquery-1.4.3.min.js"></script>
<script type="text/javascript">
var params = '{ext:"p9hp"}'; //参数，注意参数名要注意和后台方法参数名要一致
$(function(){
$("#btnOk").click(function(){
$.ajax({
type:"POST", //请求方式
url:"AjaxDemo.aspx/GetImg", //请求路径：页面/方法名字
data: params, //参数
dataType:"text",
contentType:"application/json; charset=utf-8",
beforeSend:function(XMLHttpRequest){
$("#tips").text("开始调用后头方法获取图片路径,请等待");
$("#imgFood").attr("src","image/loading.gif");
},
success:function(msg){ //成功
$("#imgFood").attr("src",eval("("+msg+")").d);
$("#tips").text("调用方法结束");
},
error:function(obj, msg, e){ //异常
alert("OH,NO");
}
});
});
});
</script>

<script type="text/javascript" src="js/jquery-1.4.3.min.js"></script> <script type="text/javascript"> var params = '{ext:"p9hp"}';  //参数，注意参数名要注意和后台方法参数名要一致                $(function(){           $("#btnOk").click(function(){            $.ajax({                type:"POST",  //请求方式                url:"AjaxDemo.aspx/GetImg",  //请求路径：页面/方法名字                data: params,     //参数                dataType:"text",                  contentType:"application/json; charset=utf-8",                beforeSend:function(XMLHttpRequest){                      $("#tips").text("开始调用后头方法获取图片路径,请等待");                    $("#imgFood").attr("src","image/loading.gif");                },                success:function(msg){  //成功                    $("#imgFood").attr("src",eval("("+msg+")").d);                      $("#tips").text("调用方法结束");                },                error:function(obj, msg, e){   //异常                    alert("OH,NO");                }                           });        });        });</script>

页面html:

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<body>
<form id="form1"runat="server">
<div>
<labelid="tips"></label>
<imgid="imgFood"/>
<inputvalue="点击我，给你看一张图片"type="button"width="35px"id="btnOk" />
</div>
</form>
</body>

<body>    <form id="form1" runat="server">    <div>    <label id="tips"></label>       <img id="imgFood" />       <input value="点击我，给你看一张图片" type="button" width="35px" id="btnOk"  />           </div>    </form></body>

后台方法：

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[System.Web.Services.WebMethod]
public staticstring GetImg(string ext)
{
System.Threading.Thread.Sleep(5000);//为了有点等待的效果，延迟5秒
StringComparer sc = StringComparer.OrdinalIgnoreCase;
string[] extArr = newstring[] { "php","asp", "aspx","txt", "bmp" };
bool f = extArr.Any(s=>sc.Equals(s,ext)); //判断传入的后缀名是否存在
if (f)
{
return "image/54222860.jpg";
}
return "image/star1.jpg";
}

  [System.Web.Services.WebMethod]        public static string GetImg(string ext)        {            System.Threading.Thread.Sleep(5000);//为了有点等待的效果，延迟5秒            StringComparer sc = StringComparer.OrdinalIgnoreCase;            string[] extArr = new string[] { "php", "asp", "aspx", "txt", "bmp" };            bool f = extArr.Any(s=>sc.Equals(s,ext));   //判断传入的后缀名是否存在                        if (f)            {                return "image/54222860.jpg";            }            return "image/star1.jpg";        }

方法三：AjaxPro (也是ajax)

第一步：下载AjaxPro.dll(或者AjaxPro.2.dll),并且添加引用到项目

第二步：修改配置文件web.config

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<system.web>
<httpHandlers>
<add verb="*" path="*.ashx" type="AjaxPro.AjaxHandlerFactory,AjaxPro.2"/>
</httpHandlers>
</system.web>

<system.web><httpHandlers>      <!--注册ajaxPro.2-->      <add verb="*" path="*.ashx" type="AjaxPro.AjaxHandlerFactory,AjaxPro.2"/>    </httpHandlers>  </system.web>

第三步：对AjaxPro在页Page_Load事件中进行运行时注册。如：

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protected void Page_Load(object sender, EventArgs e)
{
AjaxPro.Utility.RegisterTypeForAjax(typeof(AjaxDemo)); //注册
}

        protected void Page_Load(object sender, EventArgs e)        {            AjaxPro.Utility.RegisterTypeForAjax(typeof(AjaxDemo));  //注册        }

第四步：创建服务器方法，并且用[AjaxPro.AjaxMethod]标注

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[AjaxPro.AjaxMethod]
public string GetImgByAjaxPro()
{
return "image/54222860.jpg";
}

        [AjaxPro.AjaxMethod]        public string GetImgByAjaxPro()        {            return "image/54222860.jpg";        }

第五步：前台JS的调用：

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function GetMethodByAjaxPro() {
var a = JustTest.AjaxDemo.GetImgByAjaxPro();//JustTest是当前的名字空间，AjaxDemo表示后台类
document.getElementById("imgAjaxPro").src = a.value;
}