Request.Content.ReadAsMultipartAsync -- Error - asp.net-mvc

With the below code I keep getting the error: Cannot implicitly convert type 'System.Net.Http.MultipartFormDataStreamProvider' to 'System.Threading.Tasks.Task>'
MultipartFormDataStreamProvider streamProvider = new MultipartFormDataStreamProvider("c:\\tmp\\uploads");
//Error line
Task<IEnumerable<HttpContent>> bodyparts = await Request.Content.ReadAsMultipartAsync(streamProvider);
I think this is an easy one, but I'm missing it.

I ended up using this and it works great. I found it here
http://www.asp.net/web-api/overview/working-with-http/sending-html-form-data,-part-2
using System.Diagnostics;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;
using System.Web;
using System.Web.Http;
public class UploadController : ApiController
{
public async Task<HttpResponseMessage> PostFormData()
{
// Check if the request contains multipart/form-data.
if (!Request.Content.IsMimeMultipartContent())
{
throw new HttpResponseException(HttpStatusCode.UnsupportedMediaType);
}
string root = HttpContext.Current.Server.MapPath("~/App_Data");
var provider = new MultipartFormDataStreamProvider(root);
try
{
// Read the form data.
await Request.Content.ReadAsMultipartAsync(provider);
// This illustrates how to get the file names.
foreach (MultipartFileData file in provider.FileData)
{
Trace.WriteLine(file.Headers.ContentDisposition.FileName);
Trace.WriteLine("Server file path: " + file.LocalFileName);
}
return Request.CreateResponse(HttpStatusCode.OK);
}
catch (System.Exception e)
{
return Request.CreateErrorResponse(HttpStatusCode.InternalServerError, e);
}
}
}

Related

Stored procedure ADO.NET .NET Core Web API

I am building a Web API in ASP.NET Core, I am using stored procedures to be able to handle more complex queries, which with the Entity Framework is too complicated for me, I am using ADO.NET to make this connection.
I have managed to connect to a stored procedure and use the get and post methods, the point is that I don't know how to do it in order to call the other stored procedures and map a route to interact via get or post in the same project. I have only been able to do one, and I don't think it would be more convenient to create a Web API for each function that complies with a stored procedure.
My project is made up of three folders called Controller, Data, Models.
Within Models is the Value class:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
namespace ASPNETCore_StoredProcs.Models
{
public class Value
{
public int Id { get; set; }
public int Value1 { get; set; }
public string Value2 { get; set; }
}
}
Data folder has a class called ValueRepository
using ASPNETCore_StoredProcs.Models;
using Microsoft.Extensions.Configuration;
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Threading.Tasks;
namespace ASPNETCore_StoredProcs.Data
{
public class ValuesRepository
{
private readonly string _connectionString;
public ValuesRepository(IConfiguration configuration)
{
_connectionString = configuration.GetConnectionString("defaultConnection");
}
public async Task<List<Value>> GetAll()
{
using (SqlConnection sql = new SqlConnection(_connectionString))
{
using (SqlCommand cmd = new SqlCommand("GetAllValues", sql))
{
cmd.CommandType = System.Data.CommandType.StoredProcedure;
var response = new List<Value>();
await sql.OpenAsync();
using (var reader = await cmd.ExecuteReaderAsync())
{
while (await reader.ReadAsync())
{
response.Add(MapToValue(reader));
}
}
return response;
}
}
}
private Value MapToValue(SqlDataReader reader)
{
return new Value()
{
Id = (int)reader["Id"],
Value1 = (int)reader["Value1"],
Value2 = reader["Value2"].ToString()
};
}
public async Task<Value> GetById(int Id)
{
using (SqlConnection sql = new SqlConnection(_connectionString))
{
using (SqlCommand cmd = new SqlCommand("GetValueById", sql))
{
cmd.CommandType = System.Data.CommandType.StoredProcedure;
cmd.Parameters.Add(new SqlParameter("#Id", Id));
Value response = null;
await sql.OpenAsync();
using (var reader = await cmd.ExecuteReaderAsync())
{
while (await reader.ReadAsync())
{
response = MapToValue(reader);
}
}
return response;
}
}
}
public async Task Insert(Value value)
{
using (SqlConnection sql = new SqlConnection(_connectionString))
{
using (SqlCommand cmd = new SqlCommand("InsertValue", sql))
{
cmd.CommandType = System.Data.CommandType.StoredProcedure;
cmd.Parameters.Add(new SqlParameter("#value1", value.Value1));
cmd.Parameters.Add(new SqlParameter("#value2", value.Value2));
await sql.OpenAsync();
await cmd.ExecuteNonQueryAsync();
return;
}
}
}
public async Task DeleteById(int Id)
{
using (SqlConnection sql = new SqlConnection(_connectionString))
{
using (SqlCommand cmd = new SqlCommand("DeleteValue", sql))
{
cmd.CommandType = System.Data.CommandType.StoredProcedure;
cmd.Parameters.Add(new SqlParameter("#Id", Id));
await sql.OpenAsync();
await cmd.ExecuteNonQueryAsync();
return;
}
}
}
}
}
and finally I have a controller class called ValuesController:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using ASPNETCore_StoredProcs.Data;
using ASPNETCore_StoredProcs.Models;
using Microsoft.AspNetCore.Mvc;
namespace ASPNETCore_StoredProcs.Controllers
{
[Route("api/[controller]")]
[ApiController]
public class ValuesController : ControllerBase
{
private readonly ValuesRepository _repository;
public ValuesController(ValuesRepository repository)
{
this._repository = repository ?? throw new ArgumentNullException(nameof(repository));
}
// GET api/values
[HttpGet]
public async Task<ActionResult<IEnumerable<Value>>> Get()
{
return await _repository.GetAll();
}
// GET api/values/5
[HttpGet("{id}")]
public async Task<ActionResult<Value>> Get(int id)
{
var response = await _repository.GetById(id);
if (response == null) { return NotFound(); }
return response;
}
// POST api/values
[HttpPost]
public async Task Post([FromBody] Value value)
{
await _repository.Insert(value);
}
// PUT api/values/5
[HttpPut("{id}")]
public void Put(int id, [FromBody] string value)
{
}
// DELETE api/values/5
[HttpDelete("{id}")]
public async Task Delete(int id)
{
await _repository.DeleteById(id);
}
}
}
This is my startup class:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using ASPNETCore_StoredProcs.Data;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
namespace ASPNETCore_StoredProcs
{
public class Startup
{
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
services.AddScoped<ValuesRepository>();
services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
else
{
// The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
app.UseHsts();
}
app.UseHttpsRedirection();
app.UseMvc();
}
}
}
I appreciate if you can help me or if it is how I think I should create an API for each procedure that is performed thanks

Calling SignalR Hub method from client locks Xamarin android App

I finally got a SignalR Hub to work using the Microsoft.AspNet.SignalR vice the Microsoft.AspNetCore.SignalR, I was unable to get the Microsoft.AspNetCore.SignalR, no idea why. But I did get the other one to work. I am able to connect, link clients to connection id's using OnConnect and removing them using OnDisconnect. My Hub code is:
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Web;
using Microsoft.AspNet.SignalR;
using SignalrHub;
namespace SignalRChat
{
public class ChatHub : Hub
{
private static readonly List<User> Users = new List<User>();
public override Task OnConnected()
{
// string userName = Context.User.Identity.Name;
string userName = Context.QueryString["username"];
string org= Context.QueryString["organization"];
string dept = Context.QueryString["dept"];
string team = Context.QueryString["team"];
string firstname = Context.QueryString["firstname"];
string lastname = Context.QueryString["lastname"];
string connectionId = this.Context.ConnectionId;
// for now I just capture username and connection Id
var user = new User();
user.Name = userName;
user.ConnectionIds = connectionId;
try
{
Users.Add(user);
}
catch (Exception ex)
{
var msg = ex.Message;
}
// TODO: Broadcast the connected user
// send list of connected users to client
Send("Welcome " + userName, "Connected users are:");
foreach (var display in Users)
{
Send("",display.Name.ToString());
}
return base.OnConnected();
}
public override Task OnDisconnected(bool stopped)
{
string userName = Context.User.Identity.Name;
string connectionId = Context.ConnectionId;
var item = Users.Find(x => x.ConnectionIds == connectionId);
Users.Remove(item);
return base.OnDisconnected(true);
}
public void Send(string name, string message)
{
// Call the broadcastMessage method to update clients.
Clients.All.broadcastMessage(name, message);
}
public List<String> GetConnectedUsers()
{
List<string> UserNames = new List<string>();
foreach (var ConnectedUser in Users)
{
UserNames.Add(ConnectedUser.Name);
}
return UserNames;
}
}
}
Everything works fine except when I call GetConnectedUsers(), when I call that from the client with this code ConnecteduserList = client.ConnectedUsers(); the app locks up, eg; the hub never returns from that method. Clearly I'm missing something. Can anyone tell me what?
The client code in the app is:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using System.Threading.Tasks;
using Microsoft.AspNet.SignalR.Client;
namespace ChatClient.Shared
{
class Client
{
//public string username;
private readonly string _platform;
private readonly HubConnection _connection;
private readonly IHubProxy _proxy;
public event EventHandler<string> OnMessageReceived;
public Client(string platform, string username)
{
string _username = "username=" + username;
_platform = platform;
_connection = new HubConnection("https://MyApp.com/SignalRhub", _username);
_proxy = _connection.CreateHubProxy("chathub");
}
public async Task Connect()
{
await _connection.Start(); _proxy.On("broadcastMessage", (string platform, string message) =>
{
if (OnMessageReceived != null)
OnMessageReceived(this, string.Format("{0}: {1}", platform, message));
});
Send("Connected");
}
public List<string> ConnectedUsers()
{
List<string> Users = new List<string>();
// Locks up when this line is esecuted. The server log has nothing in it.
Users = _proxy.Invoke<List<string>>("GetConnectedUsers").Result;
return Users;
}
public Task Send(string message)
{
return _proxy.Invoke("Send", _platform, message);
}
}
}
Thanks to David Fowler over at GitHub who provided the link to this document (https://github.com/davidfowl/AspNetCoreDiagnosticScenarios/blob/master/AsyncGuidance.md#avoid-using-taskresult-and-taskwait), I was able to get this to work by changing my code as follows:
On the client:
From:
public List<string> ConnectedUsers()
{
// Hangs on this line
List<string> Users = _proxy.Invoke<List<string>>("getConnectedUsers").Result;
return Users;
}
To:
public async Task <List<string>> ConnectedUsers()
{
List<string> Users = await _proxy.Invoke<List<string>>("getConnectedUsers");
return Users;
}
The call to the ConnectedUsers function in Client.cs was changed as well:
From:
List<string> userList = client.ConnectedUsers();
To:
List<string> userList = await client.ConnectedUsers();
No changes to the hub code were necessary.

I can't get ios data saved on its memory (xamarin.forms - interface)

app delegate:
public override void RegisteredForRemoteNotifications(UIApplication application, NSData deviceToken)
{
// Get current device token
var DeviceToken = deviceToken.Description;
if (!string.IsNullOrWhiteSpace(DeviceToken))
{
DeviceToken = DeviceToken.Trim('<').Trim('>');
}
// Get previous device token
var oldDeviceToken = NSUserDefaults.StandardUserDefaults.StringForKey("token");
// Has the token changed?
if (string.IsNullOrEmpty(oldDeviceToken) || !oldDeviceToken.Equals(DeviceToken))
{
//TODO: Put your own logic here to notify your server that the device token has changed/been created!
}
// Save new device token
//NSUserDefaults.StandardUserDefaults.SetString(DeviceToken, "token");
IOSUserPreferences userPreference = new IOSUserPreferences();
userPreference.SetString("token", DeviceToken);
}
my PCL interface:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace neoFly_Montana
{
public interface IUserPreferences
{
void SetString(string key, string value);
string GetString(string key);
}
}
when I call the interface in pcl:
string token = App.UserPreferences.GetString("token");
App.xaml.cs:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Xamarin.Forms;
using Xamarin.Forms.Maps;
namespace neoFly_Montana
{
public partial class App : Application
{
public App()
{
InitializeComponent();
MainPage = new NavigationPage(new Views.Splash2()) { BarTextColor = Color.FromHex("#f98e1e") };
}
protected override void OnStart()
{
// Handle when your app starts
}
protected override void OnSleep()
{
// Handle when your app sleeps
}
protected override void OnResume()
{
// Handle when your app resumes
}
public static IUserPreferences UserPreferences { get; private set; }
public static void Init(IUserPreferences userPreferencesImpl)
{
App.UserPreferences = userPreferencesImpl;
}
}
}
on iphone project:
using Foundation;
using System;
using System.Collections.Generic;
using System.Text;
namespace neoFly_Montana.iOS
{
class IOSUserPreferences : IUserPreferences
{
public void SetString(string key, string value)
{
NSUserDefaults.StandardUserDefaults.SetString(value, key);
}
public string GetString(string key)
{
return NSUserDefaults.StandardUserDefaults.StringForKey(key);
}
}
}
on Android it works fine, saves and gets the data...
as a test, I tried to save a data and get it on app delegate and it worked fine, I could see it accesing the IOSUserPreferences script, the problens occurs when I try to get it on pcl
when I try to get the data that is saved, only in ios, it's null and app crashes...I noticed that it doesn't access the get string method on iphone project...
Does someone know what is happening ?

async calls using HttpClient on MVC4

I'm playing a little bit with this new technology in .net 4.5, I would like to check the code for this call and how should I control the errors or the response of my async call.
The call is working perfectly, I need full control of possible errors returned from my service.
this is my code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Newtonsoft.Json;
namespace TwitterClientMVC.Controllers
{
public class Tweets
{
public Tweet[] results;
}
public class Tweet
{
[JsonProperty("from_user")]
public string UserName { get; set; }
[JsonProperty("text")]
public string TweetText { get; set; }
}
}
public async Task<ActionResult> Index()
{
Tweets model = null;
HttpClient client = new HttpClient();
HttpResponseMessage response = await client.GetAsync("http://mywebapiservice");
response.EnsureSuccessStatusCode();
model = JsonConvert.DeserializeObject<Tweets>(response.Content.ReadAsStringAsync().Result);
return View(model.results);
}
Is this the better way to do it? or I'm missing something?
Thanks
I refactor it, is this method async as well?
public async Task<ActionResult> Index()
{
Tweets model = null;
using (HttpClient httpclient = new HttpClient())
{
model = JsonConvert.DeserializeObject<Tweets>(
await httpclient.GetStringAsync("http://search.twitter.com/search.json?q=pluralsight")
);
}
return View(model.results);
}
Is this the better way to do it?
The response.EnsureSuccessStatusCode(); will throw an exception if the status code returned by your remote service is different than 2xx. So you might want to use the IsSuccessStatusCode property instead if you want to handle the error yourself:
public async Task<ActionResult> Index()
{
using (HttpClient client = new HttpClient())
{
var response = await client.GetAsync("http://mywebapiservice");
string content = await response.Content.ReadAsStringAsync();
if (response.IsSuccessStatusCode)
{
var model = JsonConvert.DeserializeObject<Tweets>(content);
return View(model.results);
}
// an error occurred => here you could log the content returned by the remote server
return Content("An error occurred: " + content);
}
}

Issues with MultipartFormDataStreamProvider

I'm trying to follow this tutorial, and I'm realizing that even if I copy and past his code, I'm getting two compile errors in my ApiController.
IEnumerable<HttpContent> bodyparts = Request.Content.ReadAsMultipartAsync(streamProvider);
This tells me that the return of ReadAsMultipartAsync can't be cast to an IEnumerable of HttpContent.
IDictionary<string, string> bodypartFiles = streamProvider.BodyPartFileNames;
And this is telling me that BodyPartFileNames doesn't exist in streamProvider, which seems contrary to the tutorial as well as several other blog posts and StackOverflow questions I've seen.
Anyone have any idea what the deal is?
Full file:
using AsyncFileUpload.Models;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;
using System.Web.Http;
namespace AsyncFileUpload.Controllers
{
public class UploadingController : ApiController
{
private const string PATH = "C:\\_projects\\learning";
[HttpPost]
public async Task<IList<FileDesc>> Post()
{
List<FileDesc> result = new List<FileDesc>();
if (Request.Content.IsMimeMultipartContent())
{
try
{
if (!Directory.Exists(PATH))
{
Directory.CreateDirectory(PATH);
}
MultipartFormDataStreamProvider streamProvider =
new MultipartFormDataStreamProvider(PATH);
IEnumerable<HttpContent> bodyparts = Request.Content.ReadAsMultipartAsync(streamProvider);
IDictionary<string, string> bodypartFiles = streamProvider.BodyPartFileNames;
IList<string> newFiles = new List<string>();
foreach (var item in bodypartFiles)
{
var newName = string.Empty;
var file = new FileInfo(item.Value);
if (item.Key.Contains("\""))
{
newName = Path.Combine(file.Directory.ToString(),
item.Key.Substring(1, item.Key.Length - 2));
}
else
{
newName = Path.Combine(file.Directory.ToString(), item.Key);
}
File.Move(file.FullName, newName);
newFiles.Add(newName);
}
var uploadedFiles = newFiles.Select(i =>
{
var fi = new FileInfo(i);
return new FileDesc(fi.Name, fi.FullName, fi.Length);
}).ToList();
result.AddRange(uploadedFiles);
}
catch (Exception e)
{
// NOOP
}
}
return result;
}
}
}
ReadAsMultipartAsync returns a Task<> object. Take the .Result property (which blocks) or use the await keyword to wait on the task (preferable).
BodyPartFileNames was changed in the RTM release, now use the FileData property.
See: http://www.asp.net/web-api/overview/working-with-http/sending-html-form-data,-part-2

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