ASP.NET Webforms - Calling a C# method with AJAX

Question

I've an asp button on an aspx :

<asp:Button id="btnReport2" name="btnReport2"  runat="server"  class="gradientBlueBtn" Text="Show Report" OnClientClick="Alert();" ToolTip="Report"/>

As you can see, I'm calling a javascript function which uses AJAX to call a C# method. I'm doing this way :

<script>
    function Alert()
            {
                $.ajax({
                    type: "POST",
                    url: "Selection.aspx/GetReport",
                    contentType: 'application/json; charset=utf-8',
                    dataType: 'json',
                    success: function()
                    {
                        alert('success');
                    },
                    error: function()
                    {
                        alert('error');
                    }
                });

            }
</script>

The thing is, I'm always getting the error message when I'm clicking on the button. Is there something I'm doing wrong?

EDIT : The C# method. I've put a breakpoint to see if the method is called but apparently it isn't.

public void GetReport()
{
    AddFilters();
    decimal localCurrencyRate;            
    App_Data.BulkImportDSTableAdapters.ClientsTableAdapter tadptClients = new  App_Data.BulkImportDSTableAdapters.ClientsTableAdapter();
    string legalEntityID = string.Empty;           
    if (txtSrcSys.Text != null)
    {
        DataTable dtSSYS = tadptClients.GetLegalEntityID(txtSrcSys.Text);
        if (dtSSYS.Rows.Count > 0)
        {
            legalEntityID = Convert.ToString(dtSSYS.Rows[0][0]);
        }
    }
    DateTime dtInvoiceFrom = DateTime.ParseExact(txtInvoiceFrom.Text, "dd/MM/yyyy", CultureInfo.InvariantCulture);
    DateTime dtInvoiceTo = DateTime.ParseExact(txtInvoiceTo.Text, "dd/MM/yyyy", CultureInfo.InvariantCulture);
    string strInvoiceFrom = String.Format("{0:yyyyMMdd}", dtInvoiceFrom);
    string strInvoiceTo = String.Format("{0:yyyyMMdd}", dtInvoiceTo);
    string localCurrency = dbcon.getLocalCurrency(legalEntityID);
    DataSet localCurrencyDs = dbcon.getCurrencyRate(localCurrency, strInvoiceFrom);
    if (Convert.ToDecimal(localCurrencyDs.Tables[0].Rows[0]["rate"]) == 0)
        localCurrencyRate = Convert.ToDecimal(localCurrencyDs.Tables[0].Rows[1]["rate"]);
    else
        localCurrencyRate = Convert.ToDecimal(localCurrencyDs.Tables[0].Rows[0]["rate"]);
    string fileQuery = string.Empty;
    if (cbxExpYes.Checked == true && cbxExpNo.Checked == false)
    {                
        fileQuery = File.ReadAllText(Server.MapPath("~/temp/Query.txt")).Replace("{1}", "XFORM_AREA.IMPORT_GE_MAIN_V15BIS m");
        fileQuery = fileQuery.Replace(":param1", localCurrencyRate.ToString());
        fileQuery = fileQuery.Replace("{0}", qb.getFilters().Replace("P.", "m."));
    }
    if (cbxExpYes.Checked == false && cbxExpNo.Checked == true)
    {               
        fileQuery = File.ReadAllText(Server.MapPath("~/temp/Query.txt")).Replace("{1}", "PREIMPORT_GE_MAIN m");
        fileQuery = fileQuery.Replace(":param1", localCurrencyRate.ToString());
        fileQuery = fileQuery.Replace("{0}", qb.getFilters().Replace("P.", "m."));
    }
    if (cbxExpYes.Checked == true && cbxExpNo.Checked == true)
    {               
        fileQuery = File.ReadAllText(Server.MapPath("~/temp/QueryUnion.txt"));
        fileQuery = fileQuery.Replace("{ParamValues}", "pg.DEFVAL ");
        fileQuery = fileQuery.Replace("{ParamTab}", "ref_var_def pg");
        fileQuery = fileQuery.Replace("{ParamCond}", "pg.NM = 'WL_REPORTING_CUR'");
        fileQuery = fileQuery.Replace("{0}", qb.getFilters().Replace("P.", "m."));
        fileQuery = fileQuery.Replace("{1}", qb.getFilters().Replace("P.", "i."));
    }
    ASPxPivotGrid1.OptionsFilter.ShowOnlyAvailableItems = true;
    int indexTravFullName = 0;
    int indexEndTravFullName = 0;
    string paramToRemove = string.Empty;

    indexTravFullName = fileQuery.IndexOf("AND PR.ST_TRAVELLER_FULL_NAME LIKE");
    if (indexTravFullName > 0)
    {
        indexEndTravFullName = fileQuery.Substring(indexTravFullName).IndexOf("AND", 3);
        paramToRemove = fileQuery.Substring(indexTravFullName, indexEndTravFullName);
        fileQuery = fileQuery.Replace(paramToRemove, string.Empty);
    }

    if (!string.IsNullOrEmpty(fileQuery))
    {


        DataSet dsTravels = new DataSet();

        oCmd.CommandText = fileQuery;
        oCmd.CommandType = CommandType.Text;
        oCmd.Connection = oConn;
        odpter.SelectCommand = oCmd;


        odpter.SelectCommand.Parameters.Add(":pSourceSystem", txtSrcSys.Text);
        odpter.SelectCommand.Parameters.Add(":pInvoiceFrom", strInvoiceFrom);
        odpter.SelectCommand.Parameters.Add(":pInvoiceTo", strInvoiceTo);

        if (!String.IsNullOrWhiteSpace(txtCustomNr.Text))
        {
            odpter.SelectCommand.Parameters.Add(":pCustomerNr", txtCustomNr.Text);
        }
        if (!String.IsNullOrWhiteSpace(txtIATA.Text))
        {
            odpter.SelectCommand.Parameters.Add(":Iata", txtIATA.Text);
        }
        if (!String.IsNullOrWhiteSpace(txtCurrCode.Text))
        {
            odpter.SelectCommand.Parameters.Add(":CurrCode", txtCurrCode.Text);
        }
        if (!String.IsNullOrWhiteSpace(txtInvoiceNrFrom.Text))
        {
            odpter.SelectCommand.Parameters.Add(":pInvoiceNrFrom", txtInvoiceNrFrom.Text);
        }
        if (!String.IsNullOrWhiteSpace(txtInvoiceNrTo.Text))
        {
            odpter.SelectCommand.Parameters.Add(":pInvoiceNrTo", txtInvoiceNrTo.Text);
        }
        if (!String.IsNullOrWhiteSpace(txtDossierNrFrom.Text))
        {
            odpter.SelectCommand.Parameters.Add(":pDossierNrFrom", txtInvoiceNrFrom.Text);
        }
        if (!String.IsNullOrWhiteSpace(txtDossierNrFrom.Text))
        {
            odpter.SelectCommand.Parameters.Add(":pDossierNrTo", txtInvoiceNrFrom.Text);
        }
        if (!String.IsNullOrWhiteSpace(txtTravellerName.Text))
        {
            odpter.SelectCommand.Parameters.Add(":pTravellerName", txtTravellerName.Text);
        }
        if (chbxSale.Checked)
        {
            odpter.SelectCommand.Parameters.Add(":pSale", "SA");
        }
        if (chbxRefund.Checked)
        {
            odpter.SelectCommand.Parameters.Add(":pRefund", "RE");
        }
        if (hfTravelWith.Value.Contains("chbxairs"))
        {
            odpter.SelectCommand.Parameters.Add(":pProductAir", "7");
        }
        if (hfTravelWith.Value.Contains("chbxhotels"))
        {
            odpter.SelectCommand.Parameters.Add(":pProductHotel", "3");
        }
        if (hfTravelWith.Value.Contains("chbxcars"))
        {
            odpter.SelectCommand.Parameters.Add(":pProductCar", "1");
        }
        if (hfTravelWith.Value.Contains("chbxrails"))
        {
            odpter.SelectCommand.Parameters.Add(":pProductRail", "6");
        }
        if (hfTravelWith.Value.Contains("chbxmisc"))
        {
            odpter.SelectCommand.Parameters.Add(":pProductMisc", "9");
        }

        if (!String.IsNullOrWhiteSpace(txtBatchNr.Text))
        {
            odpter.SelectCommand.Parameters.Add(":pBatchNr", txtBatchNr.Text);
        }


        odpter.MissingSchemaAction = MissingSchemaAction.AddWithKey;
        odpter.Fill(dsTravels, "ReportTab");
        int count = dsTravels.Tables[0].Rows.Count;
        DataTable dt = dsTravels.Tables[0];


        if (dt.Rows.Count > 0)
        {

            ASPxPivotGrid1.DataSource = dt;
            ASPxPivotGrid1.DataBind();
            Session["dtReport"] = dt;
            //ASPxPivotGrid1.Prefilter.CriteriaString = "[" + ""  + "]";
        }
    }
}

See http://stackoverflow.com/questions/27917255/c-sharp-web-method-is-not-calling-in-javascript/27917333#27917333 — Mairaj Ahmad, Jan 18 '16 at 10:20
Try creating the post with a tool like postman, you'll get the response from your server in a readable way so you can debug more easily. Also, your function is called GetReport, and you're sending a POST, which sounds wonky, maybe this is your problem? — Glubus, Jan 18 '16 at 10:21
Please see ["Should questions include “tags” in their titles?"](http://meta.stackexchange.com/questions/19190/should-questions-include-tags-in-their-titles), where the consensus is "no, they should not"! — , Jan 18 '16 at 10:23
Thank you all for your answers. By error message, I meant the "alert('error')" which means I'm always entering into the error part. — Traffy, Jan 18 '16 at 10:26
@Glubus The is called like that but it's actually filling a pivot grid. — Traffy, Jan 18 '16 at 10:27

score 6 · Accepted Answer · edited May 23 '17 at 11:59

6

Your method must be declared as static and decorated with [WebMethod]. So, your method should be:

[WebMethod]
public static void GetReport()
{
    // Your code here
}

For more information, please take a look at this post.

EDIT!!!

I see you use some controls in your code (like txtInvoiceFrom, txtInvoiceTo). After making your method static, you cannot access those controls anymore. To solve this problem, please follow these steps (take txtInvoiceTo as an example):

Don't get data by using txtInvoiceTo.Text or something similar. Pass it as a parameter.
Get txtInvoiceTo data from client-side, using jQuery or something else (your choice), and pass it to the Ajax to post to server.
To get txtInvoiceTo data by jQuery, you can do: $('#<%= txtInvoiceTo.ClientID %>').val()

edited May 23 '17 at 11:59

Community

1
1

answered Jan 18 '16 at 10:34

Triet Doan

11,455
8
36
69

Thanks for your answer. However, I'm getting this error multiple times : an object reference is required to access non-static field method or property. – Traffy Jan 18 '16 at 10:45
Share a screenshot of your error would be really helpful :) Also, create a very simple method (just return an `int`) and call it, to prove that you can call methods using AJAX. I doubt that there are errors in your C# code. – Triet Doan Jan 18 '16 at 10:50
I tested with another method and it works (this method only returns a console message). The problem with my original method is that adding the keyword static underlines all the textboxes, checkboxes, ... declared in the aspx as non-static. – Traffy Jan 18 '16 at 11:08

score 5 · Answer 2 · edited May 23 '17 at 10:28

5

Your method must be static and decorated with [WebMethod] as below, why should make it static and decorate with [WebMethod]?

[WebMethod]
public static void GetReport()
{
    // Your code here
}

$.ajax({
    type: "POST",
    url: "Selection.aspx/GetReport",
    data: JSON.stringify({ parametername : "Parameter Value" }),
    contentType: 'application/json; charset=utf-8',
    dataType: 'json',
    success: function()
    {
        alert('success');
    },
    error: function()
    {
       alert('error');
    }
});

edited May 23 '17 at 10:28

Community

1
1

answered Jan 18 '16 at 10:22

Govinda Rajbhar

2,926
6
37
62

Thanks for your answer but I'm not using any parameter in my function. – Traffy Jan 18 '16 at 10:28
2

`JSON.stringify()` was necessary for my page methods to be able to read the data. Huge THANK YOU - none of the other SO answers have stringified answers! – JeremyW Apr 29 '19 at 15:40

Kushal Vora · Answer 3 · 2016-01-18T10:53:24.683

1

Try with this type of format.

 [System.Web.Services.WebMethod]
 public static void GetReport()
 {
 }


 [System.Web.Services.WebMethod]
 public static void GetReport(string name)
 {
 }

Get more detail from

http://www.aspsnippets.com/Articles/Call-ASPNet-Page-Method-using-jQuery-AJAX-Example.aspx

edited Jan 18 '16 at 10:53

answered Jan 18 '16 at 10:33

Kushal Vora

342
2
16

If it's your answer then mark as answer for this post – Kushal Vora Jan 18 '16 at 10:43
Thanks for your answer. However, I'm getting this error multiple times (aspx elements such as textboxes, labels, ...) : an object reference is required to access non-static field method or property. – Traffy Jan 18 '16 at 10:46
You need to pass text box value through ajax call as parameter and use those value from method. – Kushal Vora Jan 18 '16 at 10:52

score 1 · Answer 4 · edited Jun 06 '21 at 18:15

There are 3 points that must be checked:

async true in the ajax call. Example:

$.ajax({
                       type: "POST",
                       url: "<%=System.Configuration.ConfigurationManager.AppSettings["URL"]%>ClassEadArquivos.aspx/deleteArquivo",
                       date: "{FileCode: '" +FileCode + "',CodigoAulaEad: '" + <%=CodigoAulaEad.Value%> + "'}",
                       async: true,
                       contentType: "application/json",
                       success: function (response) {

static and async method in codebehind. Example:

[WebMethod()]
public static async System.Threading.Tasks.Task<string> deleteFile(string fileCode, stringCode ClassEad)
     {

if the codebehind initial method calls other asynchronous methods must all be marked as asynchronous and static.

Hi and welcome to Stack Overflow! Please visit the [help center](https://stackoverflow.com/help) for information on how to [format code](https://stackoverflow.com/help/formatting). — Tyler2P, Jun 06 '21 at 15:53

ASP.NET Webforms - Calling a C# method with AJAX

4 Answers4

Linked

Related