Json passed is null in MVC controller method

Question

I am doing below to pass Json data to My MVC controller action

Script

 var jInput = $("textarea");
 var count = 0;
 var jsonPackage = "{";
 $.each(jInput, function (i) {
 jInput[i].style.borderColor = "";
 if (jInput[i].value != "") {
 if (count != 0) {
 jsonPackage += ",";
 }
 count++;
 jsonPackage += "'" + jInput[i].id + "':'" + jInput[i].value.replace(/\\/g, "|").replace(/\'/g, "^") + "'";
 }
 });
 jsonPackage += "}";
 $.ajax({
 url: "Appraisal/LegalCheck",
 type: "POST",
 data: JSON.stringify(jsonPackage),
 dataType: "json",
 contentType: "application/json",
 success: function (retValue) {
 alert(retValue);
 }
 });

Controller method

 public Dictionary<string, Illegal[]> LegalCheck(string jsonPackage)
 {
 }

Class

 [Serializable]
 public class Illegal
 {
 public string Phrase { get; set; }
 public int StartIndex { get; set; }
 }

For some reason jsonPackage is always null in the controller method. Sample data that s being passed from the script is,

jsonPackage - {'CommentTextarea_1181_1183':'ghhgghhhgd','CommentTextarea_1181_1184':'Coments','CommentTextarea_1181_1185':'comentss'}

What am I doing wrong here? Why am I getting null in my controller method? Please suggest.

Thanks

Answer 1

try

$.ajax({
 url: "Appraisal/LegalCheck",
 type: "POST",
 data: {jsonPackage:JSON.stringify(jsonPackage)},
 dataType: "json", 
 success: function (retValue) {
 alert(retValue);
 }
 });

• San: Above change with contentType parameter commented works. but the data comes along with additional backslash and double quote

Answer 2

I would guess your JSON string isnt actually being assigned to the jsonPackage variable and so isnt being picked up by your model binder.

for a quick fix try

$.ajax({ 
 url: "Appraisal/LegalCheck", 
 type: "POST", 
 data: "jsonPackage="+JSON.stringify(jsonPackage), 
 dataType: "json", 
 contentType: "application/json", 
 success: function (retValue) { 
 alert(retValue); 
 } 
});