WebApi返回型別設定為json的三種方法
阿新 • • 發佈:2019-01-28
方法一:(改配置法)
找到Global.asax檔案,在Application_Start()方法中新增一句:
GlobalConfiguration.Configuration.Formatters.XmlFormatter.SupportedMediaTypes.Clear();
修改後:
protected void Application_Start() { AreaRegistration.RegisterAllAreas(); WebApiConfig.Register(GlobalConfiguration.Configuration); FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters); RouteConfig.RegisterRoutes(RouteTable.Routes); // 使api返回為json GlobalConfiguration.Configuration.Formatters.XmlFormatter.SupportedMediaTypes.Clear(); }
這樣返回的結果就都是json型別了,但有個不好的地方,如果返回的結果是String型別,如123,返回的json就會變成"123";
解決的方法是自定義返回型別(返回型別為HttpResponseMessage)
public HttpResponseMessage PostUserName(User user) { String userName = user.userName; HttpResponseMessage result = new HttpResponseMessage { Content = new StringContent(userName,Encoding.GetEncoding("UTF-8"), "application/json") }; return result; }
方法二:(萬金油法)
方法一中又要改配置,又要處理返回值為String型別的json,甚是麻煩,不如就不用web
api中的的自動序列化物件,自己序列化後再返回
public HttpResponseMessage PostUser(User user) { JavaScriptSerializer serializer = new JavaScriptSerializer(); string str = serializer.Serialize(user); HttpResponseMessage result = new HttpResponseMessage { Content = new StringContent(str, Encoding.GetEncoding("UTF-8"), "application/json") }; return result; }
方法二是我比較推薦的方法,為了不在每個介面中都反覆寫那幾句程式碼,所以就封裝為一個方法這樣使用就方便多了。
public static HttpResponseMessage toJson(Object obj)
{
String str;
if (obj is String ||obj is Char)
{
str = obj.ToString();
}
else
{
JavaScriptSerializer serializer = new JavaScriptSerializer();
str = serializer.Serialize(obj);
}
HttpResponseMessage result = new HttpResponseMessage { Content = new StringContent(str, Encoding.GetEncoding("UTF-8"), "application/json") };
return result;
}
方法三:(最麻煩的方法)
方法一最簡單,但殺傷力太大,所有的返回的xml格式都會被斃掉,那麼方法三就可以只讓api介面中斃掉xml,返回json
先寫一個處理返回的類:
public class JsonContentNegotiator : IContentNegotiator
{
private readonly JsonMediaTypeFormatter _jsonFormatter;
public JsonContentNegotiator(JsonMediaTypeFormatter formatter)
{
_jsonFormatter = formatter;
}
public ContentNegotiationResult Negotiate(Type type, HttpRequestMessage request, IEnumerable<MediaTypeFormatter> formatters)
{
var result = new ContentNegotiationResult(_jsonFormatter, new MediaTypeHeaderValue("application/json"));
return result;
}
}
找到App_Start中的WebApiConfig.cs檔案,開啟找到Register(HttpConfiguration config)方法
新增以下程式碼:
var jsonFormatter = new JsonMediaTypeFormatter();
config.Services.Replace(typeof(IContentNegotiator), new JsonContentNegotiator(jsonFormatter));
新增後代碼如下:
public static void Register(HttpConfiguration config)
{
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{action}/{id}",
defaults: new { id = RouteParameter.Optional }
);
var jsonFormatter = new JsonMediaTypeFormatter();
config.Services.Replace(typeof(IContentNegotiator), new JsonContentNegotiator(jsonFormatter));
}