Android调用WebAPI之传参、文件

最近把后台改成 WebAPI ，客户端向后台传参数、文件时碰到些问题：

一、传参数

用 JQuery ajax 调用后台方法时，后台方法一般定义成这样：

        [WebMethod]        [Authorize]        public string GetCustomList(string CustomerName, string Name, string Loc_Name, string selectStorageState)        {                   }

前台这样调用：

            $.ajax({                type: "POST",                url: "/Home/GetCustomList",                data: "{ \"CustomerName\":\"" + $("#CustomerName").val() + "\",\"Name\": \"" + $("#Name").val() + "\",\"Loc_Name\": \"" + $("#Loc_Name").val() + "\",\"selectStorageState\": \"" + $("#selectStorageState").val() + "\" }",                contentType: "application/json; charset=utf-8",                dataType: "json",                success: function (msg) {                  },                error: function (xhr, msg) { alert(msg); }            });

用这种方法传参在 WebAPI 里会报下面的错误：

Can’t bind multiple parameters (‘foo’ and ‘bar’) to the request’s content.

可以有以下方法解决这个报错

1、后台封装成类

WebAPI 后台：

public class User    {        public string user_name { get; set; }        public string user_password { get; set; }    }

       [HttpPost]        public string Login([FromBody]User user)        {                    }

Android 前台：

List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();            nameValuePairs.add(new BasicNameValuePair("user_name", mUserName));            nameValuePairs.add(new BasicNameValuePair("user_password", mPassword));            String resultString="";            try {                resultString= HttpHelper.invokePost("Login", nameValuePairs);            } catch (Exception e) {                            }

2、拼 json

WebAPI 后台

[HttpPost][Authorize]public string GetStockList([FromBody]string jsonString){    JObject jObject = JObject.Parse(jsonString);    page = Convert.ToInt32(jObject["page"].ToString());    pageSize = Convert.ToInt32(jObject["pageSize"].ToString());    }

Android 前台

String jsonString = "{\"page\":\""+sPage+"\",\"pageSize\":\""+sPageSize+"\"}";List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();        nameValuePairs.add(new  BasicNameValuePair("", jsonString));String resultString= HttpHelper.invokePost("GetStockList", nameValuePairs);

二、传文件

WebAPI 后台

        [Authorize]        public Task<HttpResponseMessage> Add_Img()        {             string root = HttpContext.Current.Server.MapPath("~");            string tmpRoot = root + "/App_Data";            var provider = new MultipartFormDataStreamProvider(tmpRoot);            // Read the form data and return an async task.            // 读取表单数据，并返回一个async任务            string sName = "88";            string nName = "";            string FilePath = "Uploads/";            Request.Content.Headers.ContentType.CharSet = "UTF-8";            var task = Request.Content.ReadAsMultipartAsync(provider).                ContinueWith<HttpResponseMessage>(t =>                {                     sName = provider.FileData[0].LocalFileName;                    string GpsImgJson = provider.FormData["GpsImgJson"];                    GpsImgJson = HttpUtility.UrlDecode(GpsImgJson, Encoding.GetEncoding("UTF-8"));                                       GpsImg gpsImg = JsonHelper.JsonDeserialize<GpsImg>(GpsImgJson);                    nName = gpsImg.FileName;                    FilePath += nName;                                        if (!File.Exists(root + "/" + FilePath))                    {                        File.Move(sName, root + "/" + FilePath);                    }                                    //保存                                        if (true)                    {                        return Request.CreateResponse<string>(HttpStatusCode.OK, "上传成功");                    }                    else                    {                        return Request.CreateResponse<string>(HttpStatusCode.InternalServerError, "保存出错!");                    }                                    });                      return task;        }

Android 前台

String jsonString = "{\"Title\":\""+myTitleText.getText().toString()+                                    "\",\"Content\":\""+myContentText.getText().toString()+                                    "\",\"FileName\":\""+filename+                                    "\",\"Longitude\":\""+lonString+"\",\"Latitude\":\""+latString+"\"}";                            Map<String, String> params0 = new HashMap<String, String>();                            params0.put("GpsImgJson", jsonString);                            String st= HttpHelper.invokePost("AddImg", mImageUri.getPath(), params0);

public static String invokePost(String action, String filePath, Map<String, String> params) {        try {            String url = API_URL + action + "/";            Log.d(TAG, "url is" + url);                         HttpPost httpPost = new HttpPost(url);                        File file = new File(filePath);                            MultipartEntity reqEntity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE,null,Charset.forName("UTF-8"));            FileBody fb = new FileBody(file);            reqEntity.addPart("myFile", fb);              if(params != null){                  Iterator<String> it = params.keySet().iterator();                  while(it.hasNext()){                      String name = it.next();                      reqEntity.addPart(name, new StringBody(params.get(name),Charset.forName("UTF-8")));                  }              }            httpPost.setEntity(reqEntity);              return invoke(httpPost);        } catch (Exception e) {            Log.e(TAG, e.toString());        }        return null;    }

参考网页：

http://encosia.com/using-jquery-to-post-frombody-parameters-to-web-api/

http://www.asp.net/web-api