I'm trying to POST to a website where the only parameter needed is "description." I believe it has something to do with the way that I am encoding my data. Am I missing something/going about this the wrong way?
string postData = String.Format("description=" + description + "&");
byte[] byteArray = Encoding.UTF8.GetBytes(postData);
HttpWebRequest wr = (HttpWebRequest)WebRequest.Create(url);
wr.Method = WebRequestMethods.Http.Post;
wr.ContentLength = byteArray.Length;
wr.ContentType = "application/x-www-form-urlencoded";
Stream postStream = wr.GetRequestStream();
postStream.Write(byteArray, 0, byteArray.Length);
postStream.Close();
WebResponse response = await wr.GetResponseAsync();
HttpWebResponse webResponse = (HttpWebResponse)response;
using (var stm = response.GetResponseStream())
{
using (var reader = new StreamReader(stm))
{
var content = await reader.ReadToEndAsync();
reader.Close();
stm.Close();
return content;
}
}
The stream you are trying to read apparently doesn't support seeking. You can also verify that programmatically through its CanSeek property.
If you want the same data in a stream that you can seek, consider reading the entirety of your current stream to a byte[] buffer, then constructing a MemoryStream out of that buffer for use with your StreamReader.
Related
I'm try to Send Data Using the WebRequest with POST But my problem is No data has be streamed to the server.
string user = textBox1.Text;
string password = textBox2.Text;
ASCIIEncoding encoding = new ASCIIEncoding();
string postData = "username" + user + "&password" + password;
byte[] data = encoding.GetBytes(postData);
WebRequest request = WebRequest.Create("http://localhost/s/test3.php");
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = data.Length;
Stream stream = request.GetRequestStream();
stream.Write(data, 0, data.Length);
stream.Close();
WebResponse response = request.GetResponse();
stream = response.GetResponseStream();
StreamReader sr99 = new StreamReader(stream);
MessageBox.Show(sr99.ReadToEnd());
sr99.Close();
stream.Close();
here the result
It's because you need to assign your posted parameters with the = equal sign:
byte[] data = Encoding.ASCII.GetBytes(
$"username={user}&password={password}");
WebRequest request = WebRequest.Create("http://localhost/s/test3.php");
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = data.Length;
using (Stream stream = request.GetRequestStream())
{
stream.Write(data, 0, data.Length);
}
string responseContent = null;
using (WebResponse response = request.GetResponse())
{
using (Stream stream = response.GetResponseStream())
{
using (StreamReader sr99 = new StreamReader(stream))
{
responseContent = sr99.ReadToEnd();
}
}
}
MessageBox.Show(responseContent);
See the username= and &password= in post data formatting.
You can test it on this fiddle.
Edit :
It seems that your PHP script has parameters named diffently than those used in your question.
I am facing an error that is "Stream does not support reading". I am placing a Http post request to the url. Below is my code that what i am using
var request = (HttpWebRequest) WebRequest.Create("https://test.com/Hotel Hospitality Source?method=fetchInfo");
var postData = "&username=testing";
postData += "&password=Testing";
postData += "&hotelId=h075-103";
var data = Encoding.ASCII.GetBytes(postData);
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = data.Length;
using(var ms = new MemoryStream())
request.GetRequestStream().CopyTo(ms);
var response = (HttpWebResponse) request.GetResponse();
var responseString = new StreamReader(response.GetResponseStream()).ReadToEnd();
Firstly I have used below code.
using (var stream = request.GetRequestStream())
{
stream.Write(data, 0, data.Length);
}
var response = (HttpWebResponse)request.GetResponse();
var responseString = new StreamReader(response.GetResponseStream()).ReadToEnd();
I am getting error when I am using CopyTo method for stream. How can I resolve this error?
What is using (var ms=new MemoryStream()) request.GetRequestStream().CopyTo(ms); supposed to do? You're trying to copy the request stream (which is write-only) into a new memorystream that you then dispose.
You need to write into the request stream:
using (var stream = request.GetRequestStream())
{
stream.Write(data, 0, data.Length);
}
So I have a function like so:
private String SendRequest(String jsonRequest)
{
WebRequest webRequest = WebRequest.Create(_url);
byte[] paramBytes = Encoding.UTF8.GetBytes(jsonRequest);
byte[] responseBytes;
webRequest.Method = "POST";
webRequest.ContentType = "application/json";
webRequest.ContentLength = paramBytes.Length;
webRequest.Headers.Add("X-Transmission-Session-Id", _sessionId);
using (Stream oStream = webRequest.GetRequestStream())
{
oStream.Write(paramBytes, 0, paramBytes.Length);
}
WebResponse webResponse = webRequest.GetResponse();
using (Stream iStream = webResponse.GetResponseStream())
{
responseBytes = new byte[webResponse.ContentLength];
iStream.Read(responseBytes, 0, (int) webResponse.ContentLength);
}
return Encoding.UTF8.GetString(responseBytes);
}
The problem is, at the iStream.Read() stage, some of the bytes are lost. Using wireshark reveals all the bytes are sent to this machine, however .Net is loosing them somewhere along the way. In my current debugging session, for example, where webResponse.ContentLength = 4746 byte[3949] to byte[4745] are all 0's, but they should be populated. As a result, the UTF8 JSON string cuts off early and I can't deserialise my JSON.
I thought the code was pretty clear cut, I can't see where it's going wrong to loose those bytes.
Thanks for any help!
When reading from the stream you can get less bytes than requested.
http://msdn.microsoft.com/en-us/library/system.io.stream.read.aspx
The total number of bytes read into the buffer. This can be less than
the number of bytes requested if that many bytes are not currently
available, or zero (0) if the end of the stream has been reached.
msdn example for WebResponse.GetResponseStream():
http://msdn.microsoft.com/en-us/library/system.net.webresponse.getresponsestream.aspx
I fixed it by using StreamReader instead :)
private String SendRequest(String jsonRequest)
{
WebRequest webRequest = WebRequest.Create(_url);
byte[] paramBytes = Encoding.UTF8.GetBytes(jsonRequest);
String jsonResponse;
webRequest.Method = "POST";
webRequest.ContentType = "application/json";
webRequest.ContentLength = paramBytes.Length;
webRequest.Headers.Add("X-Transmission-Session-Id", _sessionId);
using (Stream oStream = webRequest.GetRequestStream())
{
oStream.Write(paramBytes, 0, paramBytes.Length);
oStream.Close();
}
WebResponse webResponse = webRequest.GetResponse();
using (Stream iStream = webResponse.GetResponseStream())
{
StreamReader reader = new StreamReader(iStream, Encoding.UTF8);
jsonResponse = reader.ReadToEnd();
reader.Close();
iStream.Close();
}
return jsonResponse;
}
I am trying to read 500 MB text file to send it contents through HttpWebRequest. According to my requirement, I cannot send the data in chunks. Code is as follows :
using (StreamReader reader = new StreamReader(filename))
{
postData = reader.ReadToEnd();
}
byte[] byteArray = Encoding.UTF8.GetBytes(postData);
request.ContentType = "text/plain";
request.ContentLength = byteArray.Length;
Stream dataStream = request.GetRequestStream();
dataStream.Write(byteArray, 0, byteArray.Length);
dataStream.Close();
WebResponse response = request.GetResponse();
Console.WriteLine(((HttpWebResponse)response).StatusDescription);
dataStream = response.GetResponseStream();
using (StreamReader reader = new StreamReader(dataStream))
{
responseFromServer = reader.ReadToEnd();
}
Console.WriteLine(responseFromServer);
dataStream.Close();
response.Close();
Reading such large file gives me out of memory exception. Is there a way I can do this?
Sounds like you may be encountering this documented issue with HttpWebRequest. Per the KB article, try setting the HttpWebRequest.AllowWriteStreamBuffering property to false.
All files are transferred in chunks - that's what an ethernet packet is; it's a single chunk of data. I would wager that the requirement really means "this file must be transferred in a single web service call."
Assuming that's the case, you'd read the data from disk into a 64KB buffer, and then write the buffer to the request.
request.ContentType = "text/plain";
request.ContentLength = byteArray.Length;
Stream dataStream = request.GetRequestStream();
int BUFFER_SIZE = 65536;
byte[] buffer = new byte[BUFFER_SIZE];
using (StreamReader reader = new StreamReader(filename)) {
int count = 0;
while (true) {
int count = reader.Read(buffer, 0, BUFFER_SIZE);
dataStream.Write(buffer, 0, count);
if (count < BUFFER_SIZE) break;
}
}
dataStream.Close();
Need to have the server make a POST to an API, how do I add POST values to a WebRequest object and how do I send it and get the response (it will be a string) out?
I need to POST TWO values, and sometimes more, I see in these examples where it says string postData = "a string to post"; but how do I let the thing I am POSTing to know that there is multiple form values?
From MSDN
// Create a request using a URL that can receive a post.
WebRequest request = WebRequest.Create ("http://contoso.com/PostAccepter.aspx ");
// Set the Method property of the request to POST.
request.Method = "POST";
// Create POST data and convert it to a byte array.
string postData = "This is a test that posts this string to a Web server.";
byte[] byteArray = Encoding.UTF8.GetBytes (postData);
// Set the ContentType property of the WebRequest.
request.ContentType = "application/x-www-form-urlencoded";
// Set the ContentLength property of the WebRequest.
request.ContentLength = byteArray.Length;
// Get the request stream.
Stream dataStream = request.GetRequestStream ();
// Write the data to the request stream.
dataStream.Write (byteArray, 0, byteArray.Length);
// Close the Stream object.
dataStream.Close ();
// Get the response.
WebResponse response = request.GetResponse ();
// Display the status.
Console.WriteLine (((HttpWebResponse)response).StatusDescription);
// Get the stream containing content returned by the server.
dataStream = response.GetResponseStream ();
// Open the stream using a StreamReader for easy access.
StreamReader reader = new StreamReader (dataStream);
// Read the content.
string responseFromServer = reader.ReadToEnd ();
// Display the content.
Console.WriteLine (responseFromServer);
// Clean up the streams.
reader.Close ();
dataStream.Close ();
response.Close ();
Take into account that the information must be sent in the format key1=value1&key2=value2
Here's what works for me. I'm sure it can be improved, so feel free to make suggestions or edit to make it better.
const string WEBSERVICE_URL = "http://localhost/projectname/ServiceName.svc/ServiceMethod";
//This string is untested, but I think it's ok.
string jsonData = "{ \"key1\" : \"value1\", \"key2\":\"value2\" }";
try
{
var webRequest = System.Net.WebRequest.Create(WEBSERVICE_URL);
if (webRequest != null)
{
webRequest.Method = "POST";
webRequest.Timeout = 20000;
webRequest.ContentType = "application/json";
using (System.IO.Stream s = webRequest.GetRequestStream())
{
using (System.IO.StreamWriter sw = new System.IO.StreamWriter(s))
sw.Write(jsonData);
}
using (System.IO.Stream s = webRequest.GetResponse().GetResponseStream())
{
using (System.IO.StreamReader sr = new System.IO.StreamReader(s))
{
var jsonResponse = sr.ReadToEnd();
System.Diagnostics.Debug.WriteLine(String.Format("Response: {0}", jsonResponse));
}
}
}
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine(ex.ToString());
}
Here's an example of posting to a web service using the HttpWebRequest and HttpWebResponse objects.
StringBuilder sb = new StringBuilder();
string query = "?q=" + latitude + "%2C" + longitude + "&format=xml&key=xxxxxxxxxxxxxxxxxxxxxxxx";
string weatherservice = "http://api.worldweatheronline.com/free/v1/marine.ashx" + query;
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(weatherservice);
request.Referer = "http://www.yourdomain.com";
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream stream = response.GetResponseStream();
StreamReader reader = new StreamReader(stream);
Char[] readBuffer = new Char[256];
int count = reader.Read(readBuffer, 0, 256);
while (count > 0)
{
String output = new String(readBuffer, 0, count);
sb.Append(output);
count = reader.Read(readBuffer, 0, 256);
}
string xml = sb.ToString();
A more powerful and flexible example can be found here: C# File Upload with form fields, cookies and headers
Below is the code that read the data from the text file and sends it to the handler for processing and receive the response data from the handler and read it and store the data in the string builder class
//Get the data from text file that needs to be sent.
FileStream fileStream = new FileStream(#"G:\Papertest.txt", FileMode.OpenOrCreate, FileAccess.ReadWrite);
byte[] buffer = new byte[fileStream.Length];
int count = fileStream.Read(buffer, 0, buffer.Length);
//This is a handler would recieve the data and process it and sends back response.
WebRequest myWebRequest = WebRequest.Create(#"http://localhost/Provider/ProcessorHandler.ashx");
myWebRequest.ContentLength = buffer.Length;
myWebRequest.ContentType = "application/octet-stream";
myWebRequest.Method = "POST";
// get the stream object that holds request stream.
Stream stream = myWebRequest.GetRequestStream();
stream.Write(buffer, 0, buffer.Length);
stream.Close();
//Sends a web request and wait for response.
try
{
WebResponse webResponse = myWebRequest.GetResponse();
//get Stream Data from the response
Stream respData = webResponse.GetResponseStream();
//read the response from stream.
StreamReader streamReader = new StreamReader(respData);
string name;
StringBuilder str = new StringBuilder();
while ((name = streamReader.ReadLine()) != null)
{
str.Append(name); // Add to stringbuider when response contains multple lines data
}
}
catch (Exception ex)
{
throw ex;
}