How to pass multiple model as parameter in WEB API

Question

Can anyone please help me to pass multiple models as a parameter to the request's content in WEB API? I have 2 different Model Student and Employee public class Student { public int StudentId { get ; set ; } public string StudentName { get ; set ; } public string Branch { get ; set ; } } public class Employee { public int EmployeeId { get ; set ; } public string EmployeeName { get ; set ; } public string Department { get ; set ; } } I have created an API and want to pass both these models as parameters in my action method InsertTestAPI . [HttpPost] [Route( "TestAPI" )] public HttpResponseMessage InsertTestAPI(Student modelStudent, Employee modelEmployee) { // other logical operations } When I pass these models as JSON in the request body, I get the following error in Postman. { "$id" : "1" , "Message" : "An error has occurred." , "ExceptionMessage" : "Can't bind multiple parameters ('modelStudent' and 'modelEmployee') to the request's content." , "ExceptionType" : "System.InvalidOperationException" , "StackTrace" : " at System.Web.Http.Controllers.HttpActionBinding.ExecuteBindingAsync(HttpActionContext actionContext, CancellationToken cancellationToken)
 at System.Web.Http.Controllers.ActionFilterResult. d__5.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
 at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
 at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
 at System.Web.Http.Dispatcher.HttpControllerDispatcher. d__15.MoveNext()" } Can anyone please help me?

Kiran Mohanty · Answer

POST requests accept only 1 parameter as it reads data from request body. Solutions that you may wish to go for:- 1. Wrap both objects in another class and expect only instance of new object type. 2. pass one object as query string and expect another from request body( as action parameter ) Ex- api/controller/action?emp = stringifiedJson and pass student as you are passing for post request. 3. change action type to get.

Asma Khalid · Answer

First change the method defination as follow i.e. [HttpPost] [Route( "TestAPI" )] public HttpResponseMessage InsertTestAPI([FromBody]JToken postData) { // other logical operations } Then create one JSON object mapper i.e. public class ApiData { public Student StudentObj { get ; set ; } public Employee EmployeeObj { get ; set ; } } Assign your target objects to the ApiData class i.e. ApiData myData = new ApiData(); myData.StudentObj = modelStudent; myData.EmployeeObj = modelEmployee; Finally convert your 'myData' object to JSON format and pass that to your Web API. To know more about RESTful Web API Post method Development do look into https://bit.ly/2sONwnw Mark answer as accpted if helpful Thanks & Regards, Asma Khalid For More Visit: www.asmak9.com or www.bytezaar.com

swapna · Answer

viewmodel

Kiran Mohanty · Answer

HI, I was talking about 3 different approaches . Either approach 1 or 2 or 3. All 3 are not together as one solution :) .

Nikunj Satasiya · Answer

Thank you, Kiran for your valuable answer, I got a solution and it works. I have created another class and merged both models into a single unit called StudentEmployeModel public class StudentEmployeModel { public Student Students{ get ; set ;} public Employee Employees{ get ; set ;} } Then, I used this in my action method as a parameter, Actually no need to change the action type to get from the post. [HttpPost] [Route( "TestAPI" )] public HttpResponseMessage InsertTestAPI(StudentEmployeModel model) { // other logical operations } Finally, pass input parameter as JSON in request body. { "students" : { "studentId" : "1" , "studentName" : "Nikunj Satasiya" , "branch" : "computer engineering" } , "employees" : { "employeeId " :1, "employeeName" : " Nikunj Satasiya " , "department" : "IT" } } Finally, it works. Thank you.

How to pass multiple model as parameter in WEB API

Answers (5)