Ajax 处理中的“无效 JSON 原语”

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最佳答案

Just a guess what does the variable json contain after

var json = Sys.Serialization.JavaScriptSerializer.serialize(obj);?

If it is a valid json object like {"foo":"foovalue", "bar":"barvalue"} then jQuery might not send it as json data but instead serialize it to foor=foovalue&bar=barvalue thus you get the error "Invalid JSON primitive: foo"

Try instead setting the data as string

$.ajax({
...
data: '{"foo":"foovalue", "bar":"barvalue"}', //note the additional quotation marks
...
})

This way jQuery should leave the data alone and send the string as is to the server which should allow ASP.NET to parse the json server side.

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As noted by jitter, the $.ajax function serializes any object/array used as the data parameter into a url-encoded format. Oddly enough, the dataType parameter only applies to the response from the server - and not to any data in the request.

After encountering the same problem I downloaded and used the jquery-json plugin to correctly encode the request data to the ScriptService. Then, used the $.toJSON function to encode the desired arguments to send to the server:

$.ajax({
type: "POST",
url: "EditUserProfile.aspx/DeleteRecord",
data: $.toJSON(obj),
contentType: "application/json; charset=utf-8",
dataType: "json"
....
});

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I guess @jitter was right in his guess, but his solution didn't work for me.

Here is what it did work:

$.ajax({
...
data: "{ intFoo: " + intFoo + " }",
...
});

I haven't tried but i think if the parametter is a string it should be like this:

$.ajax({
...
data: "{ intFoo: " + intFoo + ", strBar: '" + strBar + "' }",
...
});

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Using

data : JSON.stringify(obj)

in the above situation would have worked I believe.

Note: You should add json2.js library all browsers don't support that JSON object (IE7-) Difference between json.js and json2.js

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On the Server, to Serialize/Deserialize json to custom objects:

public static string Serialize<T>(T obj)
{
DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());
MemoryStream ms = new MemoryStream();
serializer.WriteObject(ms, obj);
string retVal = Encoding.UTF8.GetString(ms.ToArray());
return retVal;
}


public static T Deserialize<T>(string json)
{
T obj = Activator.CreateInstance<T>();
MemoryStream ms = new MemoryStream(Encoding.Unicode.GetBytes(json));
DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());
obj = (T)serializer.ReadObject(ms);
ms.Close();
return obj;
}

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If manually formatting JSON, there is a very handy validator here: jsonlint.com

Use double quotes instead of single quotes:

Invalid:

{
'project': 'a2ab6ef4-1a8c-40cd-b561-2112b6baffd6',
'franchise': '110bcca5-cc74-416a-9e2a-f90a8c5f63a0'
}

Valid:

{
"project": "a2ab6ef4-1a8c-40cd-b561-2112b6baffd6",
"franchise": "18e899f6-dd71-41b7-8c45-5dc0919679ef"
}

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these answers just had me bouncing back and forth between invalid parameter and missing parameter.

this worked for me , just wrap string variables in quotes...

data: { RecordId: RecordId,
UserId: UId,
UserProfileId: UserProfileId,
ItemType: '"' +  ItemType + '"',
FileName: '"' +  XmlName + '"'
}

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Jquery Ajax will default send the data as query string parameters form like:

RecordId=456&UserId=123

unless the processData option is set to false, in which case it will sent as object to the server.

contentType option is for the server that in which format client has sent the data.
dataType option is for the server which tells that what type of data client is expecting back from the server.

Don't specify contentType so that server will parse them as query String parameters not as json.

OR

Use contentType as 'application/json; charset=utf-8' and use JSON.stringify(object) so that server would be able to deserialize json from string.

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I was facing the same issue, what i came with good solution is as below:

Try this...

$.ajax({
type: "POST",
url: "EditUserProfile.aspx/DeleteRecord",
data: '{RecordId: ' + RecordId + ', UserId: ' + UId + ', UserProfileId:' + UserProfileId + ', ItemType: \'' + ItemType + '\', FileName: '\' + XmlName + '\'}',
contentType: "application/json; charset=utf-8",
dataType: "json",
async: true,
cache: false,
success: function(msg) {
if (msg.d != null) {
RefreshData(ItemType, msg.d);
}
},
error: function(XMLHttpRequest, textStatus, errorThrown) {
alert("error occured during deleting");
}
});

Please note here for string type parameter i have used (\') escape sequence character for denoting it as string value.

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it's working something like this

data: JSON.stringify({'id':x}),

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I had the same issue. I was calling parent page "Save" from Popup window Close. Found that I was using ClientIDMode="Static" on both parent and popup page with same control id. Removing ClientIDMode="Static" from one of the pages solved the issue.

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Here dataTpe is "json" so, data/reqParam must be in the form of string while calling API, many as much as object as you want but at last inside $.ajax's data stringify the object.

             let person= {  name: 'john',
age: 22
};


var personStr = JSON.stringify(person);


$.ajax({
url: "@Url.Action("METHOD", "CONTROLLER")",
type: "POST",
data: JSON.stringify( { param1: personStr } ),
contentType: "application/json;charset=utf-8",
dataType: "json",
success: function (response) {


console.log("Success");


},
error: function (error) {
console.log("error found",error);
}
});

OR,

       $.ajax({
url: "@Url.Action("METHOD", "CONTROLLER")",
type: "POST",
data: personStr,
contentType: "application/json;charset=utf-8",
dataType: "json",
success: function (response) {


console.log("Success");


},
error: function (error) {
console.log("error found",error);
}
});