JavaScript calls three method instances in the background

  • 2020-03-26 21:30:02
  • OfStack

Method 1: direct use < % = % > call

JS: at the front desk

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

After method:

public static string BehindMethod()
            return " This is a background method ";

Method 2: call with ajax

Js: at the front desk

<script type="text/javascript" src="js/jquery-1.4.3.min.js"></script>
 <script type="text/javascript"> 
var params = '{ext:"p9hp"}';  //Parameter, notice that the parameter name is the same as the background method parameter name & PI;            
                type:"POST",  //Request way
                url:"AjaxDemo.aspx/GetImg",  //Request path: page/method name
                data: params,     // parameter 
                contentType:"application/json; charset=utf-8",
                    $("#tips").text(" Start calling the back method to get the image path , Please wait for ");
                success:function(msg){  // successful 
                    $("#tips").text(" End of call method ");
                error:function(obj, msg, e){   // abnormal 

The HTML page:

    <form id="form1" runat="server">
    <label id="tips"></label>
       <img id="imgFood" />
       <input value=" Click on me to show you a picture " type="button" width="35px" id="btnOk"  />


Background method:

        public static string GetImg(string ext)
            System.Threading.Thread.Sleep(5000);//Delay by 5 seconds to get some effect
            StringComparer sc = StringComparer.OrdinalIgnoreCase;
            string[] extArr = new string[] { "php", "asp", "aspx", "txt", "bmp" };
            bool f = extArr.Any(s=>sc.Equals(s,ext));   //Determines whether the passed suffix name exists

            if (f)
                return "image/54222860.jpg";
            return "image/star1.jpg";

Method 3: AjaxPro (also ajax)

Step 1: download the AjaxPro. DLL (or AjaxPro.2. DLL) and add a reference to the project

Step 2: modify the configuration file web. Config 

      <!-- registered ajaxPro.2-->
      <add verb="*" path="*.ashx" type="AjaxPro.AjaxHandlerFactory,AjaxPro.2"/>

Step 3: run time registration of AjaxPro in the page Page_Load event. Such as:

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

Step 4: create the server method and annotate it with [AjaxPro.AjaxMethod]

        public string GetImgByAjaxPro()
            return "image/54222860.jpg";

Step 5: foreground JS call:

 function GetMethodByAjaxPro() {
            var a = JustTest.AjaxDemo.GetImgByAjaxPro();//JustTest is the current namespace, and AjaxDemo is the background class
            document.getElementById("imgAjaxPro").src = a.value;

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