如何在javascript事件中通过参数调用页面方法？

Question

I have method like this in my .cs :

[System.Web.Services.WebMethod]
public static void GetServiceInformation(IInfo x) //IInfo  is an interface
{
    x.l_power = true;
    x.lb_InboxCount = UserTrans.GetInbox(int.Parse(emp_num), 0);
}

---

Now i want to call this method through a javascript method as a page method but it doesn't work .

<script type ="text/javascript">

    function GetInfo() {
        PageMethods.GetServiceInformation(this);
    }
   window.onload = setTimeout("GetInfo()", 3000);
</script>

---

  <telerik:RadScriptManager ID="RadScriptManager1" runat="server" EnablePageMethods="true">
  </telerik:RadScriptManager>

---

My .cs :

 public partial class AppMaster : Log, IInfo //My page
    {
        public string Inbox
        {
            get
            {
                return hpl_Inbox.NavigateUrl;
            }

            set
            {
                hpl_Inbox.NavigateUrl = value;
            }
        }
        public string Draft
        {
            get
            {
                return hpl_Draft.NavigateUrl;
            }

            set
            {
                hpl_Draft.NavigateUrl = value;
            }
        }

        public string New
        {
            get
            {
                return hpl_New.NavigateUrl;
            }
            set
            {
                hpl_New.NavigateUrl = value;
            }
        }
        public string Approved
        {
            get
            {
                return hpl_Approved.NavigateUrl;
            }
            set
            {
                hpl_Approved.NavigateUrl = value;
            }
        }
    //------- etc
 }

---

My interface :

public interface IInfo
    {
        string Inbox { get; set; }
        string Draft { get; set; }
        string New { get; set; }
        string Approved { get; set; }
        string archive { get; set; }
        string search { get; set; }
        string cand { get; set; }
        string pri { get; set; }
        string power { get; set; }
        string admin { get; set; }
        string help { get; set; }
        bool l_cand { get; set; }
        bool l_pri { get; set; }
        bool l_power { get; set; }
        bool l_admin { get; set; }

        string lb_ApprovedCount { get; set; }
        string lb_InboxCount { get; set; }
        string lb_archive { get; set; }
        string lb_DraftCount { get; set; }

    }

Answer 1

Answer Edit Based On Chat Discussion

First, thanks for clarifying your question. It was bit hard to understand the problem you were trying to solve. The reason? Because your code wasn't clear enough and that usually happens when there are design issues. That's effectively what your facing here a bit of a design issue. First, I'll point out some mistakes...

In this javascript function...

function GetInfo() {
        PageMethods.GetServiceInformation(this);
    }

this is NOT an instance of your page. So there's no use to make your page implement an interface...

public partial class AppMaster : Log, IInfo{}

and expect that a javascript call would page an instance of System.Web.UI.Page to your class (not to mention an implementation of the IInfo interface). You can blindly ditch this approach because it's a permanent design issue and it's not even going to work.

Now, if what you want is to serve the page, then do some further processing and finally send the results of this processing back to the client asynchronously using javascript/ajax you have a couple of approaches here:

1. Using SignalR which is my favourite approach (but you already stated your solution doesn't meet the requirements to use SignalR )
2. Using jQuery ajax which is also a very valid approach

Now, I'll explain the second approach

Using jQuery Ajax

Simply render the page as you would normally do in ASP.NET . Then on the client-side, when the page loads, make an ajax request to start processing the information you want to display. You can start the request as soon as the page loads to make the processing on the server

$(function(){
    $.ajax({
        type: 'POST',
        url: 'AppMaster.aspx/GetServiceInformation',
        data: "{}",
        contentType: 'application/json;charset=utf-8',
        dataType: 'json',
        success: function(d) {
            //load data received
            },
        error: function() {
            //process the error
            }
    });
});

In the success handler you need to load the values received from the ajax call on your web controls. Then change your IInfo interface to a concrete object in a separate code file. But, remember that this class should NOT hold any references whatsoever to your web controls

public class JSInfo
{
    string Inbox { get; set; }
    string Draft { get; set; }
    string New { get; set; }
    string Approved { get; set; }
    string archive { get; set; }
    string search { get; set; }
    string cand { get; set; }
    string pri { get; set; }
    string power { get; set; }
    string admin { get; set; }
    string help { get; set; }
    bool l_cand { get; set; }
    bool l_pri { get; set; }
    bool l_power { get; set; }
    bool l_admin { get; set; }

    string lb_ApprovedCount { get; set; }
    string lb_InboxCount { get; set; }
    string lb_archive { get; set; }
    string lb_DraftCount { get; set; }

}

then change your page method to...

[System.Web.Services.WebMethod]
public static JSInfo GetServiceInformation()
{
    //you need to get the emp_num from session

    //construct the JSInfo object
    JSInfo info = new JSInfo();

    //get the data from the database
    var data = UserTrans.GetInbox(int.Parse(emp_num), 0);

    //set the properties of the JSInfo...similar to the line below for each property...Draft, New, Approved, etc
    info.Inbox = data.Inbox;

    //return the object to the client
    return info;
}

Notice that you need to get the emp_num value from Session since you stated in the chat discussion that this value comes from a Session variable. Now, going back to the success handler of your jQuery ajax call which executes soon after the response is received back from the server. You will receive a json object in the handler parameter d with the properties of the JSInfo class that you just sent from the server. Then you set the controls on the page...

success: function(d) {
            $('#id_inbox_control').val(d.Inbox);
            $('#id_draft_control').val(d.Draft);
            $('#id_new_control').val(d.New);

            //and keep doing the same for the rest of the controls
        },

That should be a neater solution. Of coure, I cannot cover every single details here. But for sure you will get the idea. If not, let me know if I need to expand on something.

Answer 2

function GetServiceInformation(x) {

    $.ajax({
        type: "POST",
        url: "page.aspx/GetServiceInformation",
        data: "{'x':'" + x + "'}",
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        success: on_sucess,
        error: on_error
    });
    function on_sucess(data, status) {

        alert(data);

    }
    function on_error(request, status, error) {

        alert(error);
    }

}

Sorry, if it doesn't work

Answer 3

If your page implements the interface, you don't have to pass it! In your c# code write:

this.l_power=true;

If you need to pass values from JavaScript to page method, define each property as a parameter and pass values to the page method:

[System.Web.Services.WebMethod]
public static string GetServiceInformation(int value1, string value2)
{
    l_power = value1;
    something = value2;
    return "some string to indicate the result of call";
}

And:

<script type ="text/javascript">
    var v1 = 15;
    var v2 = "some value";
    function GetInfo() {
        PageMethods.GetServiceInformation(v1, v2, success, fail);
    }
   window.onload = setTimeout("GetInfo()", 3000);
</script>

in which success and fail are the names of two JS functions that will be called after the request is completed. Note that a page method can return a string value to inform the client about what happened on the server.

Answer 4

I can only think of one method.

You should somehow marshal the this object, and send it as parameter. I mean you should write a method that marshalls an object to equivalent json or xml, and POST that to your server.

I believe you can do it as you did above only through a clean API and compiler tool between C# and javascript to implement RPC just like GWT was written for java and javascript.

Answer 5

Can you do a little test?

Declare a public class JSInfo: IInfo{} in your page code, and in your web method declare that parameter of yours as JSInfo.

As JSInfo implements IInfo, your program logic can work with it without any problem.

Just to let you know, your code does not work because you cannot serialize interfaces as they are not concrete types, if you think about it, interfaces have no real correlation in XML schema. There's no way to represent the data. Base classes will work however.

If you fill bad in declaring the JSInfo in the asp.net page class, then create a class called WebMethodsHelper and declare your JavaScript WebMethod Interfaces (Adaptors) there.

public class JSInfo: IInfo{
    private ControlsCollection controls;

    public JSInfo(ControlsCollection constrols){
        this.controls = controls
        FillObjects();
    }

    private void FillObjects(){
        //iterate through controls and extract you data to you 
        //class properties/fields
    }

    public void Update(ControlsCollection controls){
        this.controls=controls;
        FillObjects();
    }

    public void Update(JSInfo info, ControlsCollection controls){
        this.controls=controls;

        //populate your object based on info

        //then extract data from page controls
        FillObjects();
    }
}


public class MyPage: System.Web.UI.Page{

     protected void Page_Load(object sender, EventArgs e){
          if(!IsPostBack && Session["info_obj"])
               Session["info_obj"] = new JSInfo(this.Controls);
     }

     [System.Web.Services.WebMethod]
     public static string GetServiceInformation(JSInfo data)
     {
         JSInfo info = new JSInfo(this.Controls);
         info.Update(data);

         //or if you stored the info in the session
         JSInfo info = (JSInfo)Session["info_obj"];
         info.Update(this.Controls, data);
     }
}

The JSInfo is just to give your IInfo interface some structure so it can be serialized.

From JavaScript you should be able to call you page method like this:

<script type ="text/javascript"> 

function GetInfo() { 
     var info = new JSInfo();
     info.PropertyXPTO="something";

     PageMethods.GetServiceInformation(info, onSuccess, onError);
} 

function onSuccess(result) {
    alert(result);
}

function onError(result) {
    alert('error: ' + result);
}

window.addEventListener("load", function(){
   setTimeout("GetInfo()", 10 * 1000); 
}, false);

</script>

Not that you should have a ScriptManager at the top of your page

<asp:ScriptManager ID="ScriptManager1" EnablePageMethods="true" runat="server" />

The ScriptManager is responsible for giving you the PageMethods class in the JavaScript, along with other things.

Also, confirm the following:

• The page method must have the System.Web.Services.WebMethod attribute. [WebMethod]
• The page method must be public. [WebMethod] public ...
• The page method must be static. [WebMethod] public static ...
• The page method must be defined on the page (either inline or in the code-behind). It cannot be defined in a control, master page, or base page.
• The ASP.NET AJAX Script Manager must have EnablePageMethods set to true.

Answer 6

function GetServiceInformation(x) {
$.ajax({
    type: "POST",
    url: "page.aspx/GetServiceInformation",
    data:  x, //Attention: there is no {}
    contentType: "application/json; charset=utf-8",
    dataType: "json",
    success: on_sucess,
    error: on_error
});
function on_sucess(data, status) {
    alert(data);
}
function on_error(request, status, error) {
    alert(error);
}
}

And then

<script type ="text/javascript">

function GetInfo() {
var myInfo = {
        Inbox: "",
        Draft: "",
        New: "",
        l_cand: ""
        ......//Attention, you should make this class corresponding to your server class IInfo
    };
    PageMethods.GetServiceInformation(myInfo);
}
window.onload = setTimeout("GetInfo()", 3000);

Referred to @anotherdie. And tell you how to transfer "X"

Answer 7

In your .js

function GetInfo() { 
    var parameter = {};
    parameter.name = "test";
    parameter.id = 123;
    parameter.state = true;

    PageMethods.GetServiceInformation(parameter, 
            function (res) {
                if (res == true) {
                     //do some
                     alert("ok");
                   } else {
                     //do some
                     alert("bad");       
                   }
            }, function(err){
               alert("ERROR: "+err._message);
            });
}

in your apsx.cs (you can return a string, a list, a bool, an int or a json object //for json use json.net http://james.newtonking.com/json ) for this i'll return a bool.

using System.Web.Services;

[WebMethod]
public static bool GetServiceInformation(ClassData parameters)
{
  try
  {
    //do some
    return true;
  }    
  catch(Exception ex)
  {
     return false;
  }
}

in a interface ClassData .cs

   public string name { get; set; }
   public int id { get; set; }
   public bool state { get; set; }

   public ClassData(){}

   public ClassData(string _name, int _id, bool _state)
   {
     this.name = _name;
     this.id= _id;
     this.state = _state;
   }

Answer 8

I do the following :

Create New Page and called it : Counts.aspx

 protected void Page_Load(object sender, EventArgs e)
        {

                        emp_num = int.Parse(Session["empnum"].ToString());
                        Thread.Sleep(3000);
                        string res = GetCounts(emp_num);
                        Response.Write(res);

        }
        /***********************************************************************************************/
        protected string GetCounts(int empNum)
        {

            string outbox = UserTransaction.getoutboxCount(empNum, 0);
            string inbox = UserTransaction.getinboxCount(empNum, 0);
            string archive = UserTransaction.getarchivecount(empNum, 0);
            string draft = UserTransaction.getdraftcount(empNum, 0);
            return outbox + "~" + inbox + "~" + archive + "~" + draft + "~";

        }

---

and in my main page :

 <script type="text/javascript">

        function loadXMLDoc() {
            var xmlhttp;
            if (window.XMLHttpRequest) {
                xmlhttp = new XMLHttpRequest();
            }
            else {
                xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
            }
            xmlhttp.onreadystatechange = function() {
                if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
                    var split = xmlhttp.responseText.split('~');

                    var outbox = split[0];
                    var inbox = split[1];
                    var archive = split[2];
                    var draft = split[3];
                    document.getElementById("lbl_DraftCount").innerHTML = draft;
                    document.getElementById("lbl_InboxCount").innerHTML = inbox;
                    document.getElementById("lbl_ApprovedCount").innerHTML = outbox;
                    document.getElementById("lbl_archive").innerHTML = archive;
                }
            }
            xmlhttp.open("GET", "Counts.aspx", true);
            xmlhttp.send();
        }
        loadXMLDoc();


    </script>