Data Annotation error message is not displaying in postman response

Question

Hi all,

 

i have web api 3.0 solution and i dont have any UI for that.All my response i have cheking in postman only .

For input validation i have used data annotation but i couldnt see the error message in post man.please help me what mistake i have done.

 

currently i am getting the error message like:

 

{

"studentid": [

"Error converting value {null} to type 'System.Int32'. Path 'studentid', line 2, position 26."

]

}

 

but i want to display the error message like:

[Required (ErrorMessage = "student Id is required.This cannot be null or blank")]
public int StudentId { get; set; }

What i have done so far:

 

1. my model

public class Employee
{
[Required (ErrorMessage = "student Id is required.This cannot be null or blank")]
public int StudentId { get; set; }
[Required (ErrorMessage = "Student name is required.This cannot be null or blank")]
[StringLength(100, MinimumLength = 2)]
public string FirstName { get; set; }
[Required]
public string LastName { get; set; }
[Required (ErrorMessage = "Student age is required.This cannot be null or blank")]
public int Age{ get; set; }
}

2. my controller

[HttpPost("api/Student/Check")]
public async Task Check([FromBody] students input)
{
if (!ModelState.IsValid)
{
returnBadRequest(Modelstate);
}
else {
returnOk();
}
}

3. created one class for ValidatorActionFilter.cs

public class ValidatorActionFilter : IActionFilter
{
public void OnActionExecuting(ActionExecutingContext filterContext)
{
if (!filterContext.ModelState.IsValid)
{
filterContext.Result = new BadRequestObjectResult(filterContext.ModelState);
}
}
public void OnActionExecuted(ActionExecutedContext filterContext)
{
}
}

startup.cs

public void ConfigureServices(IServiceCollection services)
{
services.AddMvc(options =>
{
options.Filters.Add(typeof(ValidatorActionFilter));
});
}