Canonical
How can I make an HTTP request and send some data using thePOST
method?
Here's what i use in .NET 4.8 to make a HTTP POST request. With this code one can send multiple POST requests at a time Asynchronously. At the end of each request an event is raised. And also at the end of all request another event is raised.
The one bellow is the core class:
Imports System.ComponentModel
Imports System.Text.RegularExpressions
Imports System.Timers
Imports System.Windows.Forms
Imports AeonLabs
Imports AeonLabs.Environment
Imports Newtonsoft.Json
Public Class HttpDataCore
Public Property url As String
Public Property state As New environmentVarsCore
Public Property errorMessage As String = ""
Public Property statusMessage As String
Public Property threadCount As Integer = 25
Public Property numberOfRetryAttempts = 5
Public Property queue As List(Of _queue_data_struct)
Public Property queueBWorker As Integer() ' has the size of threadCount
Public Property queueLock As New Object
Public Property retryAttempts As New _retry_attempts
Public Property dataStatistics As List(Of _data_statistics)
Public Property loadingCounter As Integer
Public Property CompletionPercentage As Integer ' value range 0-100
Public Property IsBusy As Boolean
Public Structure _queue_data_struct
Dim vars As Dictionary(Of String, String)
Dim filenameOrSavePath As String ' full address file name or full adress folder path
Dim misc As Dictionary(Of String, String)
Dim status As Integer ' -1 - completed; 0- not sent yet; 1-already sent / processing
End Structure
Public Structure _retry_attempts
Dim counter As Integer
Dim pattern As Integer
Dim previousPattern As Integer
Dim errorMessage As String
End Structure
Public Structure _data_statistics
Dim filesize As Double
Dim bytesSentReceived As Double
Dim speed As Double
End Structure
Public WithEvents RestartQueueTimer As New Timers.Timer
Public bwDataRequest() As BackgroundWorker
Public Event requestCompleted(sender As Object, requestData As String) 'TODO add misc vars
Private sendToQueue As Boolean
Public Sub New(ByVal Optional _state As environmentVarsCore = Nothing, ByVal Optional _url As String = "")
queue = New List(Of _queue_data_struct)
dataStatistics = New List(Of _data_statistics)
loadingCounter = 0
sendToQueue = False
If _state IsNot Nothing AndAlso _url.Equals("") Then
url = _state.ServerBaseAddr & _state.ApiServerAddrPath
ElseIf Not _url.Equals("") Then
url = _url
Else
Throw New System.Exception("Initialization err: state and url cannot be both null at same time")
End If
If _state IsNot Nothing Then
state = _state
End If
End Sub
Public Sub loadQueue(ByVal vars As Dictionary(Of String, String), ByVal Optional misc As Dictionary(Of String, String) = Nothing, ByVal Optional filenameOrSavePath As String = Nothing)
Dim queueItem As New _queue_data_struct
queueItem.vars = New Dictionary(Of String, String)
queueItem.misc = New Dictionary(Of String, String)
queueItem.vars = vars
queueItem.status = 0
queueItem.misc = misc
queueItem.filenameOrSavePath = filenameOrSavePath
queue.Add(queueItem)
End Sub
Public Sub clearQueue()
loadingCounter = 0
queue = New List(Of _queue_data_struct)
End Sub
Public Sub startRequest()
If bwDataRequest(0) Is Nothing Then
Throw New Exception("You need to call initialze first")
Exit Sub
End If
'startSendQueue()
IsBusy = True
AddHandler RestartQueueTimer.Elapsed, New ElapsedEventHandler(AddressOf QueueTimerTick)
With RestartQueueTimer
.Enabled = True
.Interval = 500
.Start()
End With
End Sub
Private Sub QueueTimerTick(ByVal sender As Object, ByVal e As ElapsedEventArgs)
If QueuesToComplete(queue).Equals(0) And QueuesToSend(queue).Equals(0) Then
RestartQueueTimer.Stop()
queue = New List(Of _queue_data_struct)
RaiseEvent requestCompleted(Me, Nothing)
IsBusy = False
Exit Sub
End If
If retryAttempts.counter >= numberOfRetryAttempts Then 'ToDo a retry number of attempts before quits
Threading.Thread.CurrentThread.CurrentUICulture = Globalization.CultureInfo.GetCultureInfo(state.currentLang)
Dim MsgBox As messageBoxForm
MsgBox = New messageBoxForm(retryAttempts.errorMessage & ". " & My.Resources.strings.tryAgain & " ?", My.Resources.strings.question, MessageBoxButtons.YesNo, MessageBoxIcon.Question)
If MsgBox.ShowDialog() = DialogResult.Yes Then
Dim retry As _retry_attempts
With retry
.counter = 0
.previousPattern = -1
.pattern = 0
.errorMessage = ""
End With
retryAttempts = retry
startSendQueue()
Else
RestartQueueTimer.Stop()
queue = New List(Of _queue_data_struct)
RaiseEvent requestCompleted(Me, Nothing)
IsBusy = False
Exit Sub
End If
Exit Sub
ElseIf Not sendToQueue And QueuesToSend(queue) > 0 Then
startSendQueue()
End If
End Sub
Private Sub startSendQueue()
sendToQueue = True
While QueuesToSend(queue) > 0
For shtIndex = 0 To threadCount
For i = 0 To queue.Count - 1
If Not bwDataRequest(shtIndex).IsBusy Then
SyncLock queueLock
If queue.ElementAt(i).status.Equals(0) Then
Dim data As New _queue_data_struct
data.vars = queue.ElementAt(i).vars
data.status = 1
data.misc = queue.ElementAt(i).misc
data.filenameOrSavePath = queue.ElementAt(i).filenameOrSavePath
queue(i) = data
queueBWorker(shtIndex) = i
dataStatistics(shtIndex) = (New _data_statistics)
bwDataRequest(shtIndex).RunWorkerAsync(queue(i))
Threading.Thread.Sleep(50)
End If
End SyncLock
End If
Next i
Next shtIndex
End While
sendToQueue = False
End Sub
Public Function QueuesToSend(queue As List(Of _queue_data_struct)) As Integer
Dim counter As Integer = 0
For i = 0 To queue.Count - 1
If queue(i).status.Equals(0) Then
counter += 1
End If
Next i
Return counter
End Function
Public Function QueuesToComplete(queue As List(Of _queue_data_struct)) As Integer
Dim counter As Integer = 0
For i = 0 To queue.Count - 1
If queue(i).status.Equals(1) Then
counter += 1
End If
Next i
Return counter
End Function
Public Function QueuesMultiHash(queue As List(Of _queue_data_struct)) As Integer
Dim counter As Integer = 0
For i = 0 To queue.Count - 1
If queue(i).status.Equals(1) Then
counter += i
End If
Next i
Return counter
End Function
Public Function IsBase64String(ByVal s As String) As Boolean
s = s.Trim()
Return (s.Length Mod 4 = 0) AndAlso Regex.IsMatch(s, "^[a-zA-Z0-9\+/]*={0,3}$", RegexOptions.None)
End Function
'+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Public Function ConvertDataToArray(key As String, fields As String(), response As String) As Dictionary(Of String, List(Of String))
If GetMessage(response).Equals("1001") Then
Threading.Thread.CurrentThread.CurrentUICulture = Globalization.CultureInfo.GetCultureInfo(state.currentLang)
errorMessage = "{'error':true,'message':'" & My.Resources.strings.errorNoRecordsFound & "'}"
Return Nothing
End If
Try
Dim jsonResult = JsonConvert.DeserializeObject(Of Dictionary(Of String, Object))(response)
If jsonResult.ContainsKey(key) Then
If Not jsonResult.Item(key).item(0).Count.Equals(fields.Length) Then
Threading.Thread.CurrentThread.CurrentUICulture = Globalization.CultureInfo.GetCultureInfo(state.currentLang)
errorMessage = "{'error':true,'message':'" & My.Resources.strings.JsonFieldsMismatch & ". table(" & key & "'}"
Return Nothing
Else
Dim results = New Dictionary(Of String, List(Of String))
For k = 0 To fields.Length - 1
Dim fieldValues As List(Of String) = New List(Of String)
For i = 0 To jsonResult.Item(key).Count - 1
fieldValues.Add(jsonResult.Item(key).item(i).item(k).ToString)
Next i
results.Add(fields(k), fieldValues)
Next k
Return results
End If
Else
Threading.Thread.CurrentThread.CurrentUICulture = Globalization.CultureInfo.GetCultureInfo(state.currentLang)
errorMessage = "{'error':true,'message':'" & My.Resources.strings.JsonkeyNotFound & " (" & key & "'}"
Return Nothing
End If
Catch ex As Exception
errorMessage = "{'error':true,'message':'" & ex.ToString & "'}"
errorMessage = ex.ToString
Return Nothing
End Try
End Function
End Class
the AeonLabs.Envoriment
is a class with a collection or fields and properties.
And the one bellow is for making a POST request:
Imports System.ComponentModel
Imports System.IO
Imports System.Net
Imports System.Text
Imports System.Web
Imports System.Web.Script.Serialization
Imports System.Windows.Forms
Imports AeonLabs.Environment
Imports AeonLabs.Security
Public Class HttpDataPostData
Inherits HttpDataCore
Public Event updateProgress(sender As Object, misc As Dictionary(Of String, String))
Public Event dataArrived(sender As Object, requestData As String, misc As Dictionary(Of String, String))
Public Sub New(ByVal Optional _state As environmentVarsCore = Nothing, ByVal Optional _url As String = "")
MyBase.New(_state, _url)
End Sub
Public Sub initialize(ByVal Optional _threadCount As Integer = 0)
If Not _threadCount.Equals(0) Then
threadCount = _threadCount
End If
ReDim bwDataRequest(threadCount)
ReDim queueBWorker(threadCount)
For shtIndex = 0 To threadCount
dataStatistics.Add(New _data_statistics)
bwDataRequest(shtIndex) = New System.ComponentModel.BackgroundWorker
bwDataRequest(shtIndex).WorkerReportsProgress = True
bwDataRequest(shtIndex).WorkerSupportsCancellation = True
AddHandler bwDataRequest(shtIndex).DoWork, AddressOf bwDataRequest_DoWork
AddHandler bwDataRequest(shtIndex).RunWorkerCompleted, AddressOf bwDataRequest_RunWorkerCompleted
Next shtIndex
Dim retry As _retry_attempts
With retry
.counter = 0
.previousPattern = -1
.pattern = 0
.errorMessage = ""
End With
retryAttempts = retry
End Sub
Private Sub bwDataRequest_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs)
' Find out the Index of the bWorker that called this DoWork (could be cleaner, I know)
Dim Y As Integer
Dim Index As Integer = Nothing
For Y = 0 To UBound(bwDataRequest)
If sender.Equals(bwDataRequest(Y)) Then
Index = Y
Exit For
End If
Next Y
Dim queue As _queue_data_struct
queue = e.Argument
Dim vars As New Dictionary(Of String, String)
vars = queue.vars
'TODO translation need to be local
If Not System.Net.NetworkInformation.NetworkInterface.GetIsNetworkAvailable() Then
Threading.Thread.CurrentThread.CurrentUICulture = System.Globalization.CultureInfo.GetCultureInfo(state.currentLang)
e.Result = "{'error':true,'message':'" & My.Resources.strings.errorNoNetwork & "'}"
Exit Sub
End If
If vars Is Nothing Then
e.Result = "{'error':true,'message':'missconfiguration vars'}"
Exit Sub
End If
If Not vars.ContainsKey("id") Then
vars.Add("id", state.userId)
End If
If Not vars.ContainsKey("pid") Then
Dim appId As New FingerPrint
vars.Add("pid", appId.Value)
End If
If Not vars.ContainsKey("language") Then
vars.Add("language", state.currentLang)
End If
If Not vars.ContainsKey("origin") Then
vars.Add("origin", state.softwareAccessMode)
End If
Dim serializer As New JavaScriptSerializer()
Dim json As String = serializer.Serialize(vars)
Dim encryption As New AesCipher(state)
Dim encrypted As String = HttpUtility.UrlEncode(encryption.encrypt(json))
Dim PostData = "origin=" & state.softwareAccessMode & "&data=" & encrypted
Dim request As WebRequest = WebRequest.Create(url)
Dim responseFromServer As String = ""
Dim decrypted As String = ""
request.Method = "POST"
Dim byteArray As Byte() = Encoding.UTF8.GetBytes(PostData)
request.ContentType = "application/x-www-form-urlencoded"
request.Headers.Add("Authorization", state.ApiHttpHeaderToken & "-" & state.softwareAccessMode)
request.ContentLength = byteArray.Length
Try
Dim dataStream As Stream = request.GetRequestStream()
dataStream.Write(byteArray, 0, byteArray.Length)
dataStream.Close()
Dim response As HttpWebResponse = CType(request.GetResponse(), HttpWebResponse)
dataStream = response.GetResponseStream()
Dim reader As New StreamReader(dataStream)
responseFromServer = reader.ReadToEnd()
reader.Close()
dataStream.Close()
response.Close()
If response.StatusCode = HttpStatusCode.Accepted Or response.StatusCode = 200 Then
If IsBase64String(responseFromServer) And Not responseFromServer.Equals("") Then
decrypted = encryption.decrypt((responseFromServer)).Replace("\'", "'")
Else
Threading.Thread.CurrentThread.CurrentUICulture = System.Globalization.CultureInfo.GetCultureInfo(state.currentLang)
decrypted = "{'error':true,'encrypted':false,'message':'" & My.Resources.strings.contactingCommServer & " |" & responseFromServer & "|'}"
End If
Else
Threading.Thread.CurrentThread.CurrentUICulture = System.Globalization.CultureInfo.GetCultureInfo(state.currentLang)
decrypted = "{'error':true,'message':'" & My.Resources.strings.contactingCommServer & " (" & response.StatusCode & ")', 'statuscode':'" & response.StatusCode & "'}"
End If
Catch ex As Exception
Threading.Thread.CurrentThread.CurrentUICulture = System.Globalization.CultureInfo.GetCultureInfo(state.currentLang)
decrypted = "{'error':true,'message':'" & My.Resources.strings.contactingCommServer & " (" & ex.Message.ToString.Replace("'", "\'") & ")'}"
End Try
e.Result = decrypted.Replace("\'", "'")
End Sub
Private Sub bwDataRequest_RunWorkerCompleted(ByVal sender As Object, ByVal e As System.ComponentModel.RunWorkerCompletedEventArgs)
' Find out the Index of the bWorker that called this DoWork (could be cleaner, I know)
Dim Y As Integer
Dim Index As Integer = Nothing
Dim data As New _queue_data_struct
For Y = 0 To UBound(bwDataRequest)
If sender.Equals(bwDataRequest(Y)) Then
Index = Y
Exit For
End If
Next Y
If IsResponseOk(e.Result, "statuscode") Then
data = New _queue_data_struct
data = queue(queueBWorker(Index))
data.status = 0 're queue the file
SyncLock queueLock
queue(queueBWorker(Index)) = data
End SyncLock
Dim errorMsg As String = GetMessage(e.Result)
Dim retry As _retry_attempts
With retry
.counter = retryAttempts.counter
.previousPattern = retryAttempts.previousPattern
.pattern = retryAttempts.pattern
.errorMessage = retryAttempts.errorMessage
End With
retry.errorMessage = If(retryAttempts.errorMessage.IndexOf(errorMsg) > -1, retryAttempts.errorMessage, retryAttempts.errorMessage & System.Environment.NewLine & errorMsg)
retry.pattern = QueuesMultiHash(queue)
If retry.previousPattern.Equals(retry.pattern) Then
retry.counter += 1
Else
retry.counter = 1
retry.previousPattern = retryAttempts.pattern
End If
retryAttempts = retry
Exit Sub
End If
data = New _queue_data_struct
data = queue(queueBWorker(Index))
data.status = -1 'completed sucessfully status
SyncLock queueLock
queue(queueBWorker(Index)) = data
End SyncLock
loadingCounter += 1
CompletionPercentage = (loadingCounter / queue.Count) * 100
statusMessage = "Loading data from the cloud ..."
RaiseEvent updateProgress(Me, queue(queueBWorker(Index)).misc)
RaiseEvent dataArrived(Me, e.Result, queue(queueBWorker(Index)).misc)
End Sub
End Class
The Aoenlabs.Security is a class for sending POST data encrypted using standard encryption algorithms
Simple (one-liner, no error checking, no wait for response) solution I've found so far:
(new WebClient()).UploadStringAsync(new Uri(Address), dataString);
Use with caution!
If you like a fluent API you can use Tiny.RestClient. It's available at NuGet.
var client = new TinyRestClient(new HttpClient(), "http://MyAPI.com/api");
// POST
var city = new City() { Name = "Paris", Country = "France" };
// With content
var response = await client.PostRequest("City", city)
.ExecuteAsync<bool>();
There are several ways to perform HTTP GET
and POST
requests:
Available in: .NET Framework 4.5+
, .NET Standard 1.1+
, .NET Core 1.0+
.
It is currently the preferred approach, and is asynchronous and high performance. Use the built-in version in most cases, but for very old platforms there is a NuGet package.
using System.Net.Http;
It is recommended to instantiate one HttpClient
for your application's lifetime and share it unless you have a specific reason not to.
private static readonly HttpClient client = new HttpClient();
See HttpClientFactory for a dependency injection solution.
POST
var values = new Dictionary<string, string>
{
{ "thing1", "hello" },
{ "thing2", "world" }
};
var content = new FormUrlEncodedContent(values);
var response = await client.PostAsync("http://www.example.com/recepticle.aspx", content);
var responseString = await response.Content.ReadAsStringAsync();
GET
var responseString = await client.GetStringAsync("http://www.example.com/recepticle.aspx");
RestSharp
POST
var client = new RestClient("http://example.com");
// client.Authenticator = new HttpBasicAuthenticator(username, password);
var request = new RestRequest("resource/{id}");
request.AddParameter("thing1", "Hello");
request.AddParameter("thing2", "world");
request.AddHeader("header", "value");
request.AddFile("file", path);
var response = client.Post(request);
var content = response.Content; // Raw content as string
var response2 = client.Post<Person>(request);
var name = response2.Data.Name;
Flurl.Http
It is a newer library sporting a fluent API, testing helpers, uses HttpClient under the hood, and is portable. It is available via NuGet.
using Flurl.Http;
POST
var responseString = await "http://www.example.com/recepticle.aspx"
.PostUrlEncodedAsync(new { thing1 = "hello", thing2 = "world" })
.ReceiveString();
GET
var responseString = await "http://www.example.com/recepticle.aspx"
.GetStringAsync();
Available in: .NET Framework 1.1+
, .NET Standard 2.0+
, .NET Core 1.0+
. In .NET Core, it is mostly for compatibility -- it wraps HttpClient
, is less performant, and won't get new features.
using System.Net;
using System.Text; // For class Encoding
using System.IO; // For StreamReader
POST
var request = (HttpWebRequest)WebRequest.Create("http://www.example.com/recepticle.aspx");
var postData = "thing1=" + Uri.EscapeDataString("hello");
postData += "&thing2=" + Uri.EscapeDataString("world");
var data = Encoding.ASCII.GetBytes(postData);
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = data.Length;
using (var stream = request.GetRequestStream())
{
stream.Write(data, 0, data.Length);
}
var response = (HttpWebResponse)request.GetResponse();
var responseString = new StreamReader(response.GetResponseStream()).ReadToEnd();
GET
var request = (HttpWebRequest)WebRequest.Create("http://www.example.com/recepticle.aspx");
var response = (HttpWebResponse)request.GetResponse();
var responseString = new StreamReader(response.GetResponseStream()).ReadToEnd();
This is a wrapper around HttpWebRequest
. Compare with HttpClient.
Available in: .NET Framework 1.1+
, NET Standard 2.0+
, .NET Core 2.0+
using System.Net;
using System.Collections.Specialized;
POST
using (var client = new WebClient())
{
var values = new NameValueCollection();
values["thing1"] = "hello";
values["thing2"] = "world";
var response = client.UploadValues("http://www.example.com/recepticle.aspx", values);
var responseString = Encoding.Default.GetString(response);
}
GET
using (var client = new WebClient())
{
var responseString = client.DownloadString("http://www.example.com/recepticle.aspx");
}
Simple GET request
using System.Net;
...
using (var wb = new WebClient())
{
var response = wb.DownloadString(url);
}
Simple POST request
using System.Net;
using System.Collections.Specialized;
...
using (var wb = new WebClient())
{
var data = new NameValueCollection();
data["username"] = "myUser";
data["password"] = "myPassword";
var response = wb.UploadValues(url, "POST", data);
string responseInString = Encoding.UTF8.GetString(response);
}
In .net core you can make post-call with following code, here I added some extra features to this code so can make your code work behind a proxy and with network credentials if any, also here I mention that you can change the encoding of your message. I hope this explains all and help you in coding.
HttpClient client = GetHttpClient(_config);
if (headers != null)
{
foreach (var header in headers)
{
client.DefaultRequestHeaders.TryAddWithoutValidation(header.Key, header.Value);
}
}
client.BaseAddress = new Uri(baseAddress);
Encoding encoding = Encoding.UTF8;
var result = await client.PostAsync(url, new StringContent(body, encoding, "application/json")).ConfigureAwait(false);
if (result.IsSuccessStatusCode)
{
return new RequestResponse { severity = "Success", httpResponse = result.Content.ReadAsStringAsync().Result, StatusCode = result.StatusCode };
}
else
{
return new RequestResponse { severity = "failure", httpResponse = result.Content.ReadAsStringAsync().Result, StatusCode = result.StatusCode };
}
public HttpClient GetHttpClient(IConfiguration _config)
{
bool ProxyEnable = Convert.ToBoolean(_config["GlobalSettings:ProxyEnable"]);
HttpClient client = null;
if (!ProxyEnable)
{
client = new HttpClient();
}
else
{
string ProxyURL = _config["GlobalSettings:ProxyURL"];
string ProxyUserName = _config["GlobalSettings:ProxyUserName"];
string ProxyPassword = _config["GlobalSettings:ProxyPassword"];
string[] ExceptionURL = _config["GlobalSettings:ExceptionURL"].Split(';');
bool BypassProxyOnLocal = Convert.ToBoolean(_config["GlobalSettings:BypassProxyOnLocal"]);
bool UseDefaultCredentials = Convert.ToBoolean(_config["GlobalSettings:UseDefaultCredentials"]);
WebProxy proxy = new WebProxy
{
Address = new Uri(ProxyURL),
BypassProxyOnLocal = BypassProxyOnLocal,
UseDefaultCredentials = UseDefaultCredentials,
BypassList = ExceptionURL,
Credentials = new NetworkCredential(ProxyUserName, ProxyPassword)
};
HttpClientHandler handler = new HttpClientHandler { Proxy = proxy };
client = new HttpClient(handler,true);
}
return client;
}