ASP.NET Ajax jquery input parameter is null - c#

I have a problem with this.
below are my jquery code and aspx.cs code.
I should send $('#UserID').val() to WebMethod as a parameter.
but in WebMethod it is always null.
if I change $('#UserID').val() to any string, it works well.
#UserID is correct. because I made a alert window with this value.
and.. I already changed data: '{userId: "' + $('#UserID').val() + '"}',
to data: JSON.stringify({ userId: $('#UserID').val() }).
but nothing works.
$.ajax({
url: "register.aspx/IsIdAvailable",
type: "post",
contentType: "application/json; charset=utf-8",
dataType: "json",
data: '{userId: "' + $('#UserID').val() + '"}',
dataFilter: function (data) {
var msg = JSON.parse(data);
if (msg.hasOwnProperty('d'))
return msg.d;
else
return msg;
}
})
[WebMethod]
public static bool test(string userId)
{
System.Diagnostics.Trace.WriteLine("userId: " + userId +"!");
...
}
output is always userId: !

Try changing your data attribute to something like:
data: {'userId': $("#UserID").val()}

Related

Apostrophe causes problems in AJAX method

I have a textbox (txtDescription) where the user can type a description when an event is canceled.
The problem is when the there is an apostrophe ' with in that textbox AJAX throws an error. Without the apostrophe it works and saves fine.
I have tried using JSON.stringify but this did not work.
This is my code:
$("#btnCancelEvent").click(function () {
var CencelDesc = $("#txtDescription").val();
var user = $("#lblFullName").html();
if (CencelDesc === "") {
alert("Please provide a reason why this schedule event is being canceled.");
return false;
} else {
$.ajax({
type: "POST",
url: "ScheduleOverview.aspx/CancelEvent",
data: "{'ScheduleID': '" + ScheduleID +
"','CentreID': '" + CentreID +
"','CencelDesc': '" + CencelDesc + //this is where the problem occurs
"','user': '" + user + "'}",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (response) {
swal("Information", "Schedule Event Cancelled.", "success");
$('#CancelSchedule').modal('hide');
}
});
return false;
}
return false;
});
Please assist how I can fix this issue.
Two issues:
JSON uses double quotes, not single quotes.
Never buld JSON strings by hand. Instead, build an object and let JSON.stringify handle the escaping, etc., for you.
So:
$.ajax({
type: "POST",
url: "ScheduleOverview.aspx/CancelEvent",
data: JSON.stringify({ScheduleID: ScheduleID
,CentreID: CentreID
,CencelDesc: CencelDesc
,user: user }),
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (response) {
swal("Information", "Schedule Event Cancelled.", "success");
$('#CancelSchedule').modal('hide');
}
});
Side note: There's no need for dataType: "json" in that code. You're not doing anything with the response. In fact, in general, using dataType is an anti-pattern. Instead, ensure that the server sends back the correct Content-Type header.

how to resolve ajax post jquery in asp.net page?

when i add alert(file) line after ajax block code work but when i remove alert(file) code not work .
this is work fine :
function Delete(file) {
$.ajax({
type: "POST",
url: "Image.aspx/Delete",
data: '{file: "' + file + '" }',
contentType: "application/json; charset=utf-8",
datatype: "jsondata",
async: "true",
success: function (response) {
$("#statusBox").text("ok"); //alert(response.d);
},
error: function (response) {
$("#statusBox").text("error"+response.text);
// alert(response.status + ' ' + response.statusText);
},
complete: function () {
// $("#statusBox").text("completed");
}
});
alert(file);
}
if i remove alert(file) line code web method not work.
this my c# asp.net code web method :
[WebMethod]
public static string Delete(string file)
{
try
{
// int lastSlash=file.ind
// Lesson learnt - always check for a valid URI
if (Uri.IsWellFormedUriString(file, UriKind.Absolute))
{
Uri uri = new Uri(file);
file = (uri.LocalPath);
}
//file= file.Remove(0)
//File.Delete(file);
File.Delete(HttpContext.Current.Server.MapPath(#"~\" + file.Replace("/", #"\")));
}
catch (Exception ex)
{
return ex.Message;
}
return "ok";
}
You're sending the request asynchronously,try to make false asynchronous.
for more information take a look at this
I see three (3) errors in your code:
data: '{file: "' + file + '" }',
datatype: "jsondata",
async: "true",
You are not sending a js object to the server.
jsondata is not a valid datatype.
async is a boolean and you are instead assigning a string value.
So the solution from here is:
data: {file: file }, // send a object
datatype: "text", // change to text because you are returning "ok" string
async: true, // remove the quotes
Another suggestion is try with default headers:
contentType: "application/json; charset=utf-8",
Try removing this line and see.

Unable to pass data to method

I am trying to use AJAX with ASP.NET for the first time - by trying to pass the following data to a WebMethod in my corresponding aspx page:
$.ajax({
type: "POST",
url: "myurl.aspx/SaveScreen",
data: "{'data': " + JSON.stringify(arrayRows.data) + "}",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (msg) {
alert(msg.d);
}
});
Here is my WebMethod in the aspx page. I have tried passing a simple data object which just contained one key and value, which worked successfully. When attempting to pass this object, I get an error stating that there is an internal server error with code 500.
What could I be doing wrong?
Try this:
data: {"data": JSON.stringify(arrayRows.data)}
Try this :
data: "{data: '" + JSON.stringify(arrayRows.data) + "'}"
You could wrap the data string in quotations:
$.ajax({
type: "POST",
url: "SpecifyPositioning.aspx/SaveScreen",
data: "{'data': '" + JSON.stringify(arrayRows.data) + "'}", //Added ' around JSON.stringify to pass string instead of object
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (msg) {
alert(msg.d);
}
});
This however would be a cleaner solution:
data: {"data": JSON.stringify(arrayRows.data)},

Access C# method using ajax in asp.net?

Below are both my C# and
JavaScript code, I can access this method but I'm not getting the expected output
from "success":
success: function( msg ){
alert( msg.d );
}
Instead it returns [object object]
Javascript:
$.ajax({
type: "POST",
url: "Home.aspx/UpdateSelectionStatus,
data: '{id_ver: "' + id + '" }',
contentType: "application/json; charset=utf-8",
dataType: "json",
cache: false,
success: function(msg){alert(msg.d);},
failure: function(){ }
});
C#:
[System.Web.Services.WebMethod]
[System.Web.Script.Services.ScriptMethod]
public static string UpdateSelectionStatus(string id_ver){
return "success" + id_ver;
}
That is the bug:
alert(msg.d);
just use msg directly:
success: function (msg) {alert(msg); },
You returned a simple string, not a complex type, so you haven't got any property like "d".
Please try below code: it is working at my end.
var vid = 10;
$.ajax({
type: "POST",
url: "/Home.aspx/UpdateSelectionStatus",
data: "{id_ver:'" + + vid + "'}",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (data) {
alert(data.d);
}
});
success: function( msg ){
alert( msg.d.toString());
}

jQuery.ajax "data" parameter syntax

I am trying to pass the contents of a javascript variable to the server for processing. I can pass static strings no problem but when I pass a variable containing a string, the WebMethod is not called. Here is my code:
(Client)
function expand(checkbox)
{
var selectedrow = checkbox.parentNode.parentNode;
var rowindex = selectedrow.rowIndex;
var parent = document.getElementById("parentTable");
var NextRow = parent.rows[rowindex + 1];
var cols = selectedrow.cells[1];
var ID = cols.firstElementChild.attributes.value;
$.ajax({
type: "post",
url: "Playground.aspx/childBind",
data: "{sendData: ID}",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (result) { alert("successful!" + result.d); }
})
NextRow.style.visibility = "visible";
}
(Server)
[WebMethod]
public static string childBind(string sendData)
{
return String.Format("Hello");
}
Now, if I were to try data: "{sendData: "ok"}", the WebMethod gets called and returns a response. How is my syntax wrong?
You don't have to pass it as a string. Since ID is a javascript variable you have to pass its value. When you pass data as "{sendData: ID}" it will not pass the value of ID.
Try this
data: { sendData: ID }
You were sending a string instead of an object ("{sendData: ID}" instead of {sendData: ID}). And the data you were sending wasn't JSON. So remove the contentType line and change the data line. You should re-write this as:
$.ajax({
type: "post",
url: "Playground.aspx/childBind",
data: {sendData: ID},
dataType: "json",
success: function (result) { alert("successful!" + result.d); }
})
You can also write this, if you want to send JSON:
$.ajax({
type: "post",
url: "Playground.aspx/childBind",
data: $.getJSON({sendData: ID}),
dataType: "json",
contentType: "application/json; charset=utf-8",
success: function (result) { alert("successful!" + result.d); }
})
Since you are using jQuery run these tests for the answer:
var ID = 45;
var x = "{sendData: ID}";
alert(jQuery.isPlainObject(x)); // false
var y = { sendData: ID};
alert(jQuery.isPlainObject(y)); // true
Here is the jsFiddle:
http://jsfiddle.net/3ugKE/
You are passing in 'ID' as a string rather than a variable.
All you need to do is remove the quotes around your data object.
Further reading on JSON and javascript objects:
http://www.json.org/
http://www.w3schools.com/js/js_objects.asp
you can use this code :
$.ajax({
type: "post",
url: "Playground.aspx/childBind",
data: JSON.stringify({sendData: ID}),
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (result) { alert("successful!" + result.d); }
})

Categories