如何通过Windows Phone 7将数据传递给Asp.net Web API

Question

I am wondering how do you send data back and forth when using Windows Phone 7 and asp.net web api?

I have this method in my webapi

public HttpResponseMessage Get(VerifyUserVm vm)
{
    if (ModelState.IsValid)
    {
        userService.ValidateUser(vm.Email);

        if (userService.ValidationDictionary.IsValid)
        {
            HttpResponseMessage reponse = Request.CreateResponse(HttpStatusCode.OK, userService.ValidationDictionary.ModelState["Success"]);
            return reponse;
        }
        else
        {
            return Request.CreateResponse(HttpStatusCode.BadRequest, userService.ValidationDictionary.ModelState);
        }
    }

    return Request.CreateErrorResponse(HttpStatusCode.BadRequest, ModelState);
}

public class VerifyUserVm
{
    [Required]
    public string Email { get; set; }
}

and this code in my WP7

private void btnSignIn_Click(object sender, RoutedEventArgs e)
{
    string urlPath = String.Format(WebApiHelp.ApiUrl,"user","get");            
    UriBuilder uri = new UriBuilder(urlPath);
    uri.Query = "email=" + txtEmail.Text;
    webclient.OpenReadAsync(uri.Uri);
}

the url that gets made is this: http://localhost:50570/api/user/get?email=c

but the Vm is always null.

Answer 1

Web.Api conversationally binds simple parameters (int, string, etc.) form the URL and complex types (any other custom type) from the request body.

If you want to bind a complex type VerifyUserVm from the url (eg: query string) you need to annotate the parameter with the FromUriAttribute :

public HttpResponseMessage Get([FromUri]VerifyUserVm vm)
{
     //..
}

One more thing: the casing of the properties should match:

In your VM you have Email with a uppercase E but you send email with a lower case e .

So you need to build your parameter like this:

uri.Query = "Email=" + txtEmail.Text;

For further reading: How WebAPI does Parameter Binding