How to return payload in web api?

Dear All,

I want use in payload in WEB API using asp.net c#.

{
"status":"error",
"count":2,
"type":"Error",
"results":[{
"code":"NotNull",
"message":"An appKey must be supplied",
"objectName":"requestSignature",
"propertyName":"appKey"
}, {
"code":"NotNull",
"message":"An appId must be supplied",
"objectName":"requestSignature",
"propertyName":"appId"
}]
}

Thanks & Regards,

Atul Sharma