Web api. Null method input method input method

Question

Inside my asp.net webAPI mvc controller, the delete method passed in an object called contact exits equal to zero. I have checked my code everywhere and I can not understand the reason. I have an editing operation that works in a very similar way.

So what causes the contact object parameter inside the asp.net webapi method to be a null value?

I checked, as shown in the diagram, that the contact object inside the angular controller is not null before passing to the webapi removal method.

Here is my rest of the code 

  <div data-ng-controller="ContactDeleteController">
        <form name ="deleteContact" data-ng-submit="saveDeleteContact()">
            <div>
                <label>First Name: </label>
                <input required type="text" placeholder="Enter First Name" data-ng-model="contact.FirstName"/>
            </div>
            <div>
                <label>Last Name: </label>
                <input required type="text" placeholder="Enter Last Name" data-ng-model="contact.LastName"/>
            </div>
            <div>
                <label>Email Address: </label>
                <input required type="text" placeholder="Enter Email Address" data-ng-model="contact.EmailAddress"/>
            </div>
            <div>
                <label>Cell Phone Number: </label>
                <input required type="text" placeholder="Enter Phone Number" data-ng-model="contact.PhoneNumber"/>
            </div>
            <div></div>
            <div>
                <button class="btn btn-primary" type="submit">Delete</button>
            </div>
        </form>
    </div>



    var ContactDeleteController = function ($scope, $http, $location) {
        var contactId = $location.absUrl().match(/\/Delete\/(.*)/)[1];
        $http.get("/api/ContactWeb/" + contactId)
            .then(function (response) {
                $scope.contact = response.data;
            });

        $scope.saveDeleteContact = function () {
            var con = $scope.contact;
            $http.delete("/api/ContactWeb", con)
                .then(function (response) {
                    $scope.contact = response.data;
                });
            window.location = "/Contact/Index";
        };
    };

Answer 1

HTTP DELETE . URI ( ..) -API, Contact [FromUri].

Answer 2

, - . .