Related
HttpClientHandler httpClientHandler = new HttpClientHandler();
httpClientHandler.ServerCertificateCustomValidationCallback = (message, cert, chain, errors) => { return true; };
HttpClient client = new HttpClient(httpClientHandler);
client.BaseAddress = new Uri(url);
try
{
client.Timeout = TimeSpan.FromSeconds(30);
var response = await client.PostAsync(uri, content);
if (response.IsSuccessStatusCode)
{
// do something
}
}
catch (HttpRequestException ex)
{
// do error stuff
}
catch (TaskCanceledException ex)
{
// do error stuff #2
}
catch (Exception ex)
{
// do error stuff #3
}
I am new to HttpClient.
During our test, we shut down the web service that this code is hitting in order to test this block of code. (BTW, it works as expected when the web service is running.)
Why does it take 2 minutes and 10 sec instead of 30 seconds to hit the TaskCanceledException catch?
The default timeout for HttpClient is 100 seconds. The observed 130 seems pretty strange.
If you run the following code inside dotnet fiddle, then you would see it does cancel the request after 2 seconds and will not wait for a response for 5 seconds:
using System;
using System.Net.Http;
using System.Threading.Tasks;
public class Program
{
public static async Task Main()
{
var handler = new HttpClientHandler();
var client = new HttpClient(handler);
client.BaseAddress = new Uri("https://httpstat.us");
client.Timeout = TimeSpan.FromSeconds(2);
try
{
_ = await client.GetAsync("/200?sleep=5000");
}
catch (OperationCanceledException)
{
"Timed out".Dump();
Environment.Exit(-1);
}
"Finished".Dump();
}
}
We are trying to get information from an API.
We use the following code to get an answer. It's a Xamarin Project. We are running it on an Android Emulator with internet connection. Android-Version:11.
When it gets to the line:
var result = await client.GetStringAsync(endpoint);
It just stops and doesn't throw an error. Why is this happening?
private async void Button_Clicked(object sender, EventArgs e)
{
var Get = await AsyncGet();
//await GetItemsAsync();
}
public static async Task<string> AsyncGet()
{
HttpClientHandler GetInsecureHandler()
{
HttpClientHandler handler = new HttpClientHandler();
handler.ServerCertificateCustomValidationCallback = (message, cert, chain, errors) =>
{
if (cert.Issuer.Equals("CN=localhost"))
return true;
return errors == System.Net.Security.SslPolicyErrors.None;
};
return handler;
}
var client = new HttpClient(GetInsecureHandler());
try
{
var endpoint = new Uri("My Uri");
var result = await client.GetStringAsync(endpoint);
var json = JsonConvert.DeserializeObject<string>(result);
return result;
}
catch (Exception ex)
{
string checkResult = "Error " + ex.ToString();
client.Dispose();
return checkResult;
}
}
Alternative code:
async Task<string> GetItemsAsync()
{
using (HttpClient client = new HttpClient())
{
var response = await client.GetAsync("My Uri");
return await response.Content.ReadAsStringAsync();
}
}
This Code does return the information but only in the console. When it is run with Xamarin, it also doesn't return anything.
I wrote simple method for getting data from (online) REST Service:
public async Task<Object> GetTask()
{
try
{
using (HttpClient client = new HttpClient())
{
client.BaseAddress = new Uri("http://111.111.111.111:8080/");
HttpResponseMessage result = await client.GetAsync("ABC/CDE/getsomeinfo");
if (result.IsSuccessStatusCode)
{
//Deserialize
}
}
}
catch (Exception ex)
{
Debug.WriteLine("Error" + ex);
}
return null;
}
Whenever i run this on UWP i'm getting catch exception:
The text associated with this error code could not be found.
A connection with the server could not be established
HResult 2147012867
Im trying to connect my client with restapi in internal network. In forms same code is working properly.
Try this
HttpResponseMessage response;
public async Task<string> webserviceResponse(string HttpMethod)
{
// check internet connection is available or not
if (NetworkInterface.GetIsNetworkAvailable() == true)
{
// CancellationTokenSource cts = new CancellationTokenSource(2000); // 2 seconds
HttpClient client = new HttpClient();
MultipartFormDataContent mfdc = new MultipartFormDataContent();
mfdc.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data");
string GenrateUrl = "your url";
if (HttpMethod == "POST")
{
response = await client.PostAsync(GenrateUrl, mfdc);
}
else if (HttpMethod == "PUT")
{
response = await client.PutAsync(GenrateUrl, mfdc);
}
else if (HttpMethod == "GET")
{
response = await client.GetAsync(GenrateUrl);
}
var respon = await response.Content.ReadAsStringAsync();
string convert_response = respon.ToString();
return convert_response;
}
else
{
return "0";
}
}
What is a simple way of downloading a file from a URL path?
using (var client = new WebClient())
{
client.DownloadFile("http://example.com/file/song/a.mpeg", "a.mpeg");
}
Include this namespace
using System.Net;
Download Asynchronously and put a ProgressBar to show the status of the download within the UI Thread Itself
private void BtnDownload_Click(object sender, RoutedEventArgs e)
{
using (WebClient wc = new WebClient())
{
wc.DownloadProgressChanged += wc_DownloadProgressChanged;
wc.DownloadFileAsync (
// Param1 = Link of file
new System.Uri("http://www.sayka.com/downloads/front_view.jpg"),
// Param2 = Path to save
"D:\\Images\\front_view.jpg"
);
}
}
// Event to track the progress
void wc_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)
{
progressBar.Value = e.ProgressPercentage;
}
Use System.Net.WebClient.DownloadFile:
string remoteUri = "http://www.contoso.com/library/homepage/images/";
string fileName = "ms-banner.gif", myStringWebResource = null;
// Create a new WebClient instance.
using (WebClient myWebClient = new WebClient())
{
myStringWebResource = remoteUri + fileName;
// Download the Web resource and save it into the current filesystem folder.
myWebClient.DownloadFile(myStringWebResource, fileName);
}
using System.Net;
WebClient webClient = new WebClient();
webClient.DownloadFile("http://mysite.com/myfile.txt", #"c:\myfile.txt");
WebRequest, WebClient, and ServicePoint are obsolete from .NET 6 (source - 11/2021).
Use the System.Net.Http.HttpClient class instead:
using (var client = new HttpClient())
{
using (var s = client.GetStreamAsync("https://via.placeholder.com/150"))
{
using (var fs = new FileStream("localfile.jpg", FileMode.OpenOrCreate))
{
s.Result.CopyTo(fs);
}
}
}
Async version of the same code:
using var client = new HttpClient();
using var s = await client.GetStreamAsync("https://via.placeholder.com/150");
using var fs = new FileStream("localfile.jpg", FileMode.OpenOrCreate);
await s.CopyToAsync(fs);
Complete class to download a file while printing status to console.
using System;
using System.ComponentModel;
using System.IO;
using System.Net;
using System.Threading;
class FileDownloader
{
private readonly string _url;
private readonly string _fullPathWhereToSave;
private bool _result = false;
private readonly SemaphoreSlim _semaphore = new SemaphoreSlim(0);
public FileDownloader(string url, string fullPathWhereToSave)
{
if (string.IsNullOrEmpty(url)) throw new ArgumentNullException("url");
if (string.IsNullOrEmpty(fullPathWhereToSave)) throw new ArgumentNullException("fullPathWhereToSave");
this._url = url;
this._fullPathWhereToSave = fullPathWhereToSave;
}
public bool StartDownload(int timeout)
{
try
{
System.IO.Directory.CreateDirectory(Path.GetDirectoryName(_fullPathWhereToSave));
if (File.Exists(_fullPathWhereToSave))
{
File.Delete(_fullPathWhereToSave);
}
using (WebClient client = new WebClient())
{
var ur = new Uri(_url);
// client.Credentials = new NetworkCredential("username", "password");
client.DownloadProgressChanged += WebClientDownloadProgressChanged;
client.DownloadFileCompleted += WebClientDownloadCompleted;
Console.WriteLine(#"Downloading file:");
client.DownloadFileAsync(ur, _fullPathWhereToSave);
_semaphore.Wait(timeout);
return _result && File.Exists(_fullPathWhereToSave);
}
}
catch (Exception e)
{
Console.WriteLine("Was not able to download file!");
Console.Write(e);
return false;
}
finally
{
this._semaphore.Dispose();
}
}
private void WebClientDownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)
{
Console.Write("\r --> {0}%.", e.ProgressPercentage);
}
private void WebClientDownloadCompleted(object sender, AsyncCompletedEventArgs args)
{
_result = !args.Cancelled;
if (!_result)
{
Console.Write(args.Error.ToString());
}
Console.WriteLine(Environment.NewLine + "Download finished!");
_semaphore.Release();
}
public static bool DownloadFile(string url, string fullPathWhereToSave, int timeoutInMilliSec)
{
return new FileDownloader(url, fullPathWhereToSave).StartDownload(timeoutInMilliSec);
}
}
Usage:
static void Main(string[] args)
{
var success = FileDownloader.DownloadFile(fileUrl, fullPathWhereToSave, timeoutInMilliSec);
Console.WriteLine("Done - success: " + success);
Console.ReadLine();
}
Try using this:
private void downloadFile(string url)
{
string file = System.IO.Path.GetFileName(url);
WebClient cln = new WebClient();
cln.DownloadFile(url, file);
}
Also you can use DownloadFileAsync method in WebClient class. It downloads to a local file the resource with the specified URI. Also this method does not block the calling thread.
Sample:
webClient.DownloadFileAsync(new Uri("http://www.example.com/file/test.jpg"), "test.jpg");
For more information:
http://csharpexamples.com/download-files-synchronous-asynchronous-url-c/
Check for a network connection using GetIsNetworkAvailable() to avoid creating empty files when not connected to a network.
if (System.Net.NetworkInformation.NetworkInterface.GetIsNetworkAvailable())
{
using (System.Net.WebClient client = new System.Net.WebClient())
{
client.DownloadFileAsync(new Uri("http://www.examplesite.com/test.txt"),
"D:\\test.txt");
}
}
WebClient is obsolete
If you want to download to a file avoid first reading to memory by using ResponseHeadersRead like this:
static public async Task HttpDownloadFileAsync(HttpClient httpClient, string url, string fileToWriteTo) {
using HttpResponseMessage response = await httpClient.GetAsync(url, HttpCompletionOption.ResponseHeadersRead);
using Stream streamToReadFrom = await response.Content.ReadAsStreamAsync();
using Stream streamToWriteTo = File.Open(fileToWriteTo, FileMode.Create);
await streamToReadFrom.CopyToAsync(streamToWriteTo);
}
Above code is more of an outline, adding correct error/exception handling is not trivial, also progress report is not trivial, as is Disposing.
I came up with a set of C# 9.0 extension classes for DownoadFileAsync, GetToStringAsync and PostToStringAsync
namespace System.Net.Http {
// HttpResponse is in one of 3 states:
// - ResponseMessageInfo is object && ResponseMessageInfo.IsSuccessStatusCode -> success, inspect ResponseMessageInfo for StatusCode etc
// - ResponseMessageInfo is object && !ResponseMessageInfo.IsSuccessStatusCode -> failure, inspect ResponseMessageInfo for StatusCode, ReasonPhrase etc
// - ResponseMessageInfo is null -> exception, inspect ExceptionInfo fields
public record HttpResponse {
// copies of HttpRequestMessage and HttpResponseMessage which do not have the content and do not need to be disposed
public record HttpRequestMessageInfo(HttpRequestHeaders Headers, HttpMethod Method, HttpRequestOptions Options, Uri? RequestUri, Version Version, HttpVersionPolicy VersionPolicy);
public record HttpResponseMessageInfo(HttpResponseHeaders Headers, bool IsSuccessStatusCode, string? ReasonPhrase, HttpRequestMessageInfo RequestMessage, HttpStatusCode StatusCode, HttpResponseHeaders TrailingHeaders, Version Version);
// holds Http exception information
public record HttpExceptionInfo(HttpRequestMessageInfo HttpRequestMessage, string ErrorMessage, WebExceptionStatus? WebExceptionStatus);
// if ResponseMessageInfo is null ExceptionInfo is not and vice versa
public HttpResponseMessageInfo? ResponseMessageInfo { get; init; }
public HttpExceptionInfo? ExceptionInfo { get; init; }
public HttpResponse(HttpRequestMessage requestMessage, HttpResponseMessage responseMessage) {
var requestMessageInfo = new HttpRequestMessageInfo(requestMessage.Headers, requestMessage.Method, requestMessage.Options, requestMessage.RequestUri, requestMessage.Version, requestMessage.VersionPolicy);
ResponseMessageInfo = new(responseMessage.Headers, responseMessage.IsSuccessStatusCode, responseMessage.ReasonPhrase, requestMessageInfo, responseMessage.StatusCode, responseMessage.TrailingHeaders, responseMessage.Version);
ExceptionInfo = null;
}
public HttpResponse(HttpRequestMessage requestMessage, Exception exception) {
ResponseMessageInfo = null;
var requestMessageInfo = new HttpRequestMessageInfo(requestMessage.Headers, requestMessage.Method, requestMessage.Options, requestMessage.RequestUri, requestMessage.Version, requestMessage.VersionPolicy);
if (exception is WebException ex1 && ex1.Status == WebExceptionStatus.ProtocolError) {
using HttpWebResponse? httpResponse = (HttpWebResponse?)ex1.Response;
ExceptionInfo = new(requestMessageInfo, httpResponse?.StatusDescription ?? "", ex1.Status);
}
else if (exception is WebException ex2) ExceptionInfo = new(requestMessageInfo, ex2.FullMessage(), ex2.Status);
else if (exception is TaskCanceledException ex3 && ex3.InnerException is TimeoutException) ExceptionInfo = new(requestMessageInfo, ex3.InnerException.FullMessage(), WebExceptionStatus.Timeout);
else if (exception is TaskCanceledException ex4) ExceptionInfo = new(requestMessageInfo, ex4.FullMessage(), WebExceptionStatus.RequestCanceled);
else ExceptionInfo = new(requestMessageInfo, exception.FullMessage(), null);
}
public override string ToString() {
if (ResponseMessageInfo is object) {
var msg = ResponseMessageInfo.IsSuccessStatusCode ? "Success" : "Failure";
msg += $" {Enum.GetName(typeof(HttpStatusCode), ResponseMessageInfo.StatusCode)}";
if (ResponseMessageInfo.ReasonPhrase is object) msg += $" {ResponseMessageInfo.ReasonPhrase}";
return msg;
} else if (ExceptionInfo is object) {
var msg = "Failure";
msg += $" {ExceptionInfo.ErrorMessage}";
if (ExceptionInfo.WebExceptionStatus is object) msg += $" {Enum.GetName(typeof(WebExceptionStatus), ExceptionInfo.WebExceptionStatus)}";
return msg;
}
return "NA"; // never reach here
}
}
public static class ExtensionMethods {
// progressCallback recieves (bytesRecieved, percent, speedKbSec) and can return false to cancell download
public static async Task<(bool success, HttpResponse httpResponse)> DownloadFileAsync(this HttpClient httpClient, Uri requestUri, string fileToWriteTo, CancellationTokenSource? cts = null, Func<long, int, float, bool>? progressCallback = null) {
var httpRequestMessage = new HttpRequestMessage { Method = HttpMethod.Get, RequestUri = requestUri };
var created = false;
try {
var cancellationToken = cts?.Token ?? default;
using HttpResponseMessage httpResponseMessage = await httpClient.SendAsync(httpRequestMessage, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
if (!httpResponseMessage.IsSuccessStatusCode) return (false, new(httpRequestMessage, httpResponseMessage));
var contentLength = httpResponseMessage.Content.Headers.ContentLength;
using Stream streamToReadFrom = await httpResponseMessage.Content.ReadAsStreamAsync();
using Stream streamToWriteTo = File.Open(fileToWriteTo, FileMode.Create);
created = true;
var buffer = new byte[81920];
var bytesRecieved = (long)0;
var stopwatch = Stopwatch.StartNew();
int bytesInBuffer;
while ((bytesInBuffer = await streamToReadFrom.ReadAsync(buffer, cancellationToken)) != 0) {
await streamToWriteTo.WriteAsync(buffer.AsMemory(0, bytesInBuffer), cancellationToken);
bytesRecieved += bytesInBuffer;
if (progressCallback is object) {
var percent = contentLength is object && contentLength != 0 ? (int)Math.Floor(bytesRecieved / (float)contentLength * 100.0) : 0;
var speedKbSec = (float)((bytesRecieved / 1024.0) / (stopwatch.ElapsedMilliseconds / 1000.0));
var proceed = progressCallback(bytesRecieved, percent, speedKbSec);
if (!proceed) {
httpResponseMessage.ReasonPhrase = "Callback cancelled download";
httpResponseMessage.StatusCode = HttpStatusCode.PartialContent;
return (false, new(httpRequestMessage, httpResponseMessage));
}
}
}
return (true, new(httpRequestMessage, httpResponseMessage));
}
catch (Exception ex) {
if (created) try { File.Delete(fileToWriteTo); } catch { };
return (false, new(httpRequestMessage, ex));
}
}
public static async Task<(string? ResponseAsString, HttpResponse httpResponse)> GetToStringAsync(this HttpClient httpClient, Uri requestUri, CancellationTokenSource? cts = null) {
var httpRequestMessage = new HttpRequestMessage { Method = HttpMethod.Get, RequestUri = requestUri };
try {
var cancellationToken = cts?.Token ?? default;
using var httpResponseMessage = await httpClient.SendAsync(httpRequestMessage, cancellationToken);
if (!httpResponseMessage.IsSuccessStatusCode) return (null, new(httpRequestMessage, httpResponseMessage));
var responseAsString = await httpResponseMessage.Content.ReadAsStringAsync();
return (responseAsString, new(httpRequestMessage, httpResponseMessage));
}
catch (Exception ex) {
return (null, new(httpRequestMessage, ex)); ;
}
}
public static async Task<(string? ResponseAsString, HttpResponse httpResponse)> PostToStringAsync(this HttpClient httpClient, Uri requestUri, HttpContent postBuffer, CancellationTokenSource? cts = null) {
var httpRequestMessage = new HttpRequestMessage { Method = HttpMethod.Post, RequestUri = requestUri, Content = postBuffer };
try {
var cancellationToken = cts?.Token ?? default;
using var httpResponseMessage = await httpClient.SendAsync(httpRequestMessage, cancellationToken);
if (!httpResponseMessage.IsSuccessStatusCode) return (null, new(httpRequestMessage, httpResponseMessage));
var responseAsString = await httpResponseMessage.Content.ReadAsStringAsync();
return (responseAsString, new(httpRequestMessage, httpResponseMessage));
}
catch (Exception ex) {
return (null, new(httpRequestMessage, ex));
}
}
}
}
namespace System {
public static class ExtensionMethods {
public static string FullMessage(this Exception ex) {
if (ex is AggregateException aex) return aex.InnerExceptions.Aggregate("[ ", (total, next) => $"{total}[{next.FullMessage()}] ") + "]";
var msg = ex.Message.Replace(", see inner exception.", "").Trim();
var innerMsg = ex.InnerException?.FullMessage();
if (innerMsg is object && innerMsg!=msg) msg = $"{msg} [ {innerMsg} ]";
return msg;
}
}
}
To use:
// download to file
var lastPercent = 0;
bool progressCallback(long bytesRecieved, int percent, float speedKbSec) {
if (percent > lastPercent) {
lastPercent = percent;
Log($"Downloading... {percent}% {speedKbSec/1024.0:0.00}Mbps");
}
return true;
}
var (success, httpResponse) = await httpClient.DownloadFileAsync(
new(myUrlString),
localFileName,
null, // CancellationTokenSource
progressCallback
);
if (success) {
// file downloaded to localFile, httpResponse.ResponseMessageInfo contain
// extra information ie headers and status code
} else {
Log(httpResponse.ToString()); // human friendly error information
// if httpResponse.ResponseMessageInfo is object then server refused the request -
// examine httpResponse.ResponseMessageInfo.HttpStatusCode etc
// else we had a Http exception - examine httpResponse.ExceptionInfo
}
// Http get
var (responseAsString, httpResponse) = await httpClient.GetToStringAsync(url);
if (responseAsString is object) {
// responseAsString contains the string response from the server
} else {
// as for DownloadFileAsync
}
// http post
var postBuffer = new StringContent(jsonInString, System.Text.Encoding.UTF8, "application/x-www-form-urlencoded");
var (responseAsString, httpResponse) = await httpClient.PostToStringAsync(url, postBuffer);
if (responseAsString is object) {
// responseAsString contains the string response from the server
} else {
Log(httpResponse.ToString()); // human friendly error informaiton
// as for DownloadFileAsync
}
Below code contain logic for download file with original name
private string DownloadFile(string url)
{
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
string filename = "";
string destinationpath = Environment;
if (!Directory.Exists(destinationpath))
{
Directory.CreateDirectory(destinationpath);
}
using (HttpWebResponse response = (HttpWebResponse)request.GetResponseAsync().Result)
{
string path = response.Headers["Content-Disposition"];
if (string.IsNullOrWhiteSpace(path))
{
var uri = new Uri(url);
filename = Path.GetFileName(uri.LocalPath);
}
else
{
ContentDisposition contentDisposition = new ContentDisposition(path);
filename = contentDisposition.FileName;
}
var responseStream = response.GetResponseStream();
using (var fileStream = File.Create(System.IO.Path.Combine(destinationpath, filename)))
{
responseStream.CopyTo(fileStream);
}
}
return Path.Combine(destinationpath, filename);
}
There are a lot of answers but this is the solution I used recently for .NET 6 or greater.
using var httpClient = new HttpClient();
var tempPath = Path.GetTempFileName();
await using var s = await HttpClient.GetStreamAsync(pdfFilePath);
await using var fs = File.OpenWrite(tempPath);
await s.CopyToAsync(fs);
As per my research I found that WebClient.DownloadFileAsync is the best way to download file. It is available in System.Net namespace and it supports .net core as well.
Here is the sample code to download the file.
using System;
using System.IO;
using System.Net;
using System.ComponentModel;
public class Program
{
public static void Main()
{
new Program().Download("ftp://localhost/test.zip");
}
public void Download(string remoteUri)
{
string FilePath = Directory.GetCurrentDirectory() + "/tepdownload/" + Path.GetFileName(remoteUri); // path where download file to be saved, with filename, here I have taken file name from supplied remote url
using (WebClient client = new WebClient())
{
try
{
if (!Directory.Exists("tepdownload"))
{
Directory.CreateDirectory("tepdownload");
}
Uri uri = new Uri(remoteUri);
//password username of your file server eg. ftp username and password
client.Credentials = new NetworkCredential("username", "password");
//delegate method, which will be called after file download has been complete.
client.DownloadFileCompleted += new AsyncCompletedEventHandler(Extract);
//delegate method for progress notification handler.
client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(ProgessChanged);
// uri is the remote url where filed needs to be downloaded, and FilePath is the location where file to be saved
client.DownloadFileAsync(uri, FilePath);
}
catch (Exception)
{
throw;
}
}
}
public void Extract(object sender, AsyncCompletedEventArgs e)
{
Console.WriteLine("File has been downloaded.");
}
public void ProgessChanged(object sender, DownloadProgressChangedEventArgs e)
{
Console.WriteLine($"Download status: {e.ProgressPercentage}%.");
}
}
With above code file will be downloaded inside tepdownload folder of the project's directory. Please read comment in code to understand what above code do.
In the event that you need to set Headers and Cookies to download a file, you will need to do things slightly differently. Here is an example...
// Pass in the HTTPGET URL, Full Path w/Filename, and a populated Cookie Container (optional)
private async Task DownloadFileRequiringHeadersAndCookies(string getUrl, string fullPath, CookieContainer cookieContainer, CancellationToken cancellationToken)
{
cookieContainer ??= new CookieContainer(); // TODO: FILL ME AND PASS ME IN
using (var handler = new HttpClientHandler()
{
UseCookies = true,
CookieContainer = cookieContainer, // This will, both, use the cookies passed in, and update/create cookies from the response
ServerCertificateCustomValidationCallback = (message, cert, chain, errors) => true, // use only if it gets angry about the SSL endpoints
AllowAutoRedirect = true,
})
{
using (var client = new HttpClient(handler))
{
SetHeaders(client);
using (var response = await client.GetAsync(getUrl, cancellationToken))
{
if (response.IsSuccessStatusCode)
{
var bytes = await response.Content.ReadAsByteArrayAsync(cancellationToken);
await File.WriteAllBytesAsync(fullPath, bytes, cancellationToken); // This overwrites the file
}
else
{
// TODO: HANDLE ME
throw new FileNotFoundException();
}
}
}
}
}
And, to add the Headers you need with this...
private void SetHeaders(HttpClient client)
{
// TODO: SET ME
client.DefaultRequestHeaders.Connection.Add("keep-alive");
client.DefaultRequestHeaders.Add("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) ...");
client.DefaultRequestHeaders.Add("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9, ...");
client.DefaultRequestHeaders.AcceptEncoding.Add(new StringWithQualityHeaderValue("gzip"));
client.DefaultRequestHeaders.AcceptEncoding.Add(new StringWithQualityHeaderValue("deflate"));
client.DefaultRequestHeaders.AcceptLanguage.Add(new StringWithQualityHeaderValue("en-US"));
client.DefaultRequestHeaders.AcceptLanguage.Add(new StringWithQualityHeaderValue("en", .9));
...
}
ASIDE: You can fill the CookieContainer by:
Looping through the cookies of a previous Response.
This response could be from HttpAgilityPack, or WebClient, or Puppeteer (lots of options)
Manually entries (from config values or hard coded values).
You may need to know the status and update a ProgressBar during the file download or use credentials before making the request.
Here it is, an example that covers these options. Lambda notation and String interpolation has been used:
using System.Net;
// ...
using (WebClient client = new WebClient()) {
Uri ur = new Uri("http://remotehost.do/images/img.jpg");
//client.Credentials = new NetworkCredential("username", "password");
String credentials = Convert.ToBase64String(Encoding.ASCII.GetBytes("Username" + ":" + "MyNewPassword"));
client.Headers[HttpRequestHeader.Authorization] = $"Basic {credentials}";
client.DownloadProgressChanged += (o, e) =>
{
Console.WriteLine($"Download status: {e.ProgressPercentage}%.");
// updating the UI
Dispatcher.Invoke(() => {
progressBar.Value = e.ProgressPercentage;
});
};
client.DownloadDataCompleted += (o, e) =>
{
Console.WriteLine("Download finished!");
};
client.DownloadFileAsync(ur, #"C:\path\newImage.jpg");
}
static void Main(string[] args)
{
DownloadFileAsync().GetAwaiter();
Console.WriteLine("File was downloaded");
Console.Read();
}
private static async Task DownloadFileAsync()
{
WebClient client = new WebClient();
await client.DownloadFileTaskAsync(new Uri("http://somesite.com/myfile.txt"), "mytxtFile.txt");
}
This is my solution, it works fine:
public static void DownloadFile(string url, string pathToSaveFile)
{
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
// or: ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072;
using (WebDownload client = new WebDownload())
{
client.Headers["User-Agent"] = "User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36";
client.DownloadFile(new Uri(url), pathToSaveFile);
}
}
public class WebDownload : WebClient
{
protected override WebRequest GetWebRequest(Uri address)
{
HttpWebRequest request = (HttpWebRequest)base.GetWebRequest(address);
if (request != null)
{
request.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
}
return request;
}
}
In .NET Core MVC, you can sometimes do it as simply as:
public async Task<ActionResult> DownloadUrl(string url) {
return Redirect(url);
}
This probably assumes that the MIME type you're trying to download is set to be downloadable by the browser (e.g. .mp4), so it doesn't try to redirect to a webpage.
What is a simple way of downloading a file from a URL path?
using (var client = new WebClient())
{
client.DownloadFile("http://example.com/file/song/a.mpeg", "a.mpeg");
}
Include this namespace
using System.Net;
Download Asynchronously and put a ProgressBar to show the status of the download within the UI Thread Itself
private void BtnDownload_Click(object sender, RoutedEventArgs e)
{
using (WebClient wc = new WebClient())
{
wc.DownloadProgressChanged += wc_DownloadProgressChanged;
wc.DownloadFileAsync (
// Param1 = Link of file
new System.Uri("http://www.sayka.com/downloads/front_view.jpg"),
// Param2 = Path to save
"D:\\Images\\front_view.jpg"
);
}
}
// Event to track the progress
void wc_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)
{
progressBar.Value = e.ProgressPercentage;
}
Use System.Net.WebClient.DownloadFile:
string remoteUri = "http://www.contoso.com/library/homepage/images/";
string fileName = "ms-banner.gif", myStringWebResource = null;
// Create a new WebClient instance.
using (WebClient myWebClient = new WebClient())
{
myStringWebResource = remoteUri + fileName;
// Download the Web resource and save it into the current filesystem folder.
myWebClient.DownloadFile(myStringWebResource, fileName);
}
using System.Net;
WebClient webClient = new WebClient();
webClient.DownloadFile("http://mysite.com/myfile.txt", #"c:\myfile.txt");
WebRequest, WebClient, and ServicePoint are obsolete from .NET 6 (source - 11/2021).
Use the System.Net.Http.HttpClient class instead:
using (var client = new HttpClient())
{
using (var s = client.GetStreamAsync("https://via.placeholder.com/150"))
{
using (var fs = new FileStream("localfile.jpg", FileMode.OpenOrCreate))
{
s.Result.CopyTo(fs);
}
}
}
Async version of the same code:
using var client = new HttpClient();
using var s = await client.GetStreamAsync("https://via.placeholder.com/150");
using var fs = new FileStream("localfile.jpg", FileMode.OpenOrCreate);
await s.CopyToAsync(fs);
Complete class to download a file while printing status to console.
using System;
using System.ComponentModel;
using System.IO;
using System.Net;
using System.Threading;
class FileDownloader
{
private readonly string _url;
private readonly string _fullPathWhereToSave;
private bool _result = false;
private readonly SemaphoreSlim _semaphore = new SemaphoreSlim(0);
public FileDownloader(string url, string fullPathWhereToSave)
{
if (string.IsNullOrEmpty(url)) throw new ArgumentNullException("url");
if (string.IsNullOrEmpty(fullPathWhereToSave)) throw new ArgumentNullException("fullPathWhereToSave");
this._url = url;
this._fullPathWhereToSave = fullPathWhereToSave;
}
public bool StartDownload(int timeout)
{
try
{
System.IO.Directory.CreateDirectory(Path.GetDirectoryName(_fullPathWhereToSave));
if (File.Exists(_fullPathWhereToSave))
{
File.Delete(_fullPathWhereToSave);
}
using (WebClient client = new WebClient())
{
var ur = new Uri(_url);
// client.Credentials = new NetworkCredential("username", "password");
client.DownloadProgressChanged += WebClientDownloadProgressChanged;
client.DownloadFileCompleted += WebClientDownloadCompleted;
Console.WriteLine(#"Downloading file:");
client.DownloadFileAsync(ur, _fullPathWhereToSave);
_semaphore.Wait(timeout);
return _result && File.Exists(_fullPathWhereToSave);
}
}
catch (Exception e)
{
Console.WriteLine("Was not able to download file!");
Console.Write(e);
return false;
}
finally
{
this._semaphore.Dispose();
}
}
private void WebClientDownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)
{
Console.Write("\r --> {0}%.", e.ProgressPercentage);
}
private void WebClientDownloadCompleted(object sender, AsyncCompletedEventArgs args)
{
_result = !args.Cancelled;
if (!_result)
{
Console.Write(args.Error.ToString());
}
Console.WriteLine(Environment.NewLine + "Download finished!");
_semaphore.Release();
}
public static bool DownloadFile(string url, string fullPathWhereToSave, int timeoutInMilliSec)
{
return new FileDownloader(url, fullPathWhereToSave).StartDownload(timeoutInMilliSec);
}
}
Usage:
static void Main(string[] args)
{
var success = FileDownloader.DownloadFile(fileUrl, fullPathWhereToSave, timeoutInMilliSec);
Console.WriteLine("Done - success: " + success);
Console.ReadLine();
}
Try using this:
private void downloadFile(string url)
{
string file = System.IO.Path.GetFileName(url);
WebClient cln = new WebClient();
cln.DownloadFile(url, file);
}
Also you can use DownloadFileAsync method in WebClient class. It downloads to a local file the resource with the specified URI. Also this method does not block the calling thread.
Sample:
webClient.DownloadFileAsync(new Uri("http://www.example.com/file/test.jpg"), "test.jpg");
For more information:
http://csharpexamples.com/download-files-synchronous-asynchronous-url-c/
Check for a network connection using GetIsNetworkAvailable() to avoid creating empty files when not connected to a network.
if (System.Net.NetworkInformation.NetworkInterface.GetIsNetworkAvailable())
{
using (System.Net.WebClient client = new System.Net.WebClient())
{
client.DownloadFileAsync(new Uri("http://www.examplesite.com/test.txt"),
"D:\\test.txt");
}
}
WebClient is obsolete
If you want to download to a file avoid first reading to memory by using ResponseHeadersRead like this:
static public async Task HttpDownloadFileAsync(HttpClient httpClient, string url, string fileToWriteTo) {
using HttpResponseMessage response = await httpClient.GetAsync(url, HttpCompletionOption.ResponseHeadersRead);
using Stream streamToReadFrom = await response.Content.ReadAsStreamAsync();
using Stream streamToWriteTo = File.Open(fileToWriteTo, FileMode.Create);
await streamToReadFrom.CopyToAsync(streamToWriteTo);
}
Above code is more of an outline, adding correct error/exception handling is not trivial, also progress report is not trivial, as is Disposing.
I came up with a set of C# 9.0 extension classes for DownoadFileAsync, GetToStringAsync and PostToStringAsync
namespace System.Net.Http {
// HttpResponse is in one of 3 states:
// - ResponseMessageInfo is object && ResponseMessageInfo.IsSuccessStatusCode -> success, inspect ResponseMessageInfo for StatusCode etc
// - ResponseMessageInfo is object && !ResponseMessageInfo.IsSuccessStatusCode -> failure, inspect ResponseMessageInfo for StatusCode, ReasonPhrase etc
// - ResponseMessageInfo is null -> exception, inspect ExceptionInfo fields
public record HttpResponse {
// copies of HttpRequestMessage and HttpResponseMessage which do not have the content and do not need to be disposed
public record HttpRequestMessageInfo(HttpRequestHeaders Headers, HttpMethod Method, HttpRequestOptions Options, Uri? RequestUri, Version Version, HttpVersionPolicy VersionPolicy);
public record HttpResponseMessageInfo(HttpResponseHeaders Headers, bool IsSuccessStatusCode, string? ReasonPhrase, HttpRequestMessageInfo RequestMessage, HttpStatusCode StatusCode, HttpResponseHeaders TrailingHeaders, Version Version);
// holds Http exception information
public record HttpExceptionInfo(HttpRequestMessageInfo HttpRequestMessage, string ErrorMessage, WebExceptionStatus? WebExceptionStatus);
// if ResponseMessageInfo is null ExceptionInfo is not and vice versa
public HttpResponseMessageInfo? ResponseMessageInfo { get; init; }
public HttpExceptionInfo? ExceptionInfo { get; init; }
public HttpResponse(HttpRequestMessage requestMessage, HttpResponseMessage responseMessage) {
var requestMessageInfo = new HttpRequestMessageInfo(requestMessage.Headers, requestMessage.Method, requestMessage.Options, requestMessage.RequestUri, requestMessage.Version, requestMessage.VersionPolicy);
ResponseMessageInfo = new(responseMessage.Headers, responseMessage.IsSuccessStatusCode, responseMessage.ReasonPhrase, requestMessageInfo, responseMessage.StatusCode, responseMessage.TrailingHeaders, responseMessage.Version);
ExceptionInfo = null;
}
public HttpResponse(HttpRequestMessage requestMessage, Exception exception) {
ResponseMessageInfo = null;
var requestMessageInfo = new HttpRequestMessageInfo(requestMessage.Headers, requestMessage.Method, requestMessage.Options, requestMessage.RequestUri, requestMessage.Version, requestMessage.VersionPolicy);
if (exception is WebException ex1 && ex1.Status == WebExceptionStatus.ProtocolError) {
using HttpWebResponse? httpResponse = (HttpWebResponse?)ex1.Response;
ExceptionInfo = new(requestMessageInfo, httpResponse?.StatusDescription ?? "", ex1.Status);
}
else if (exception is WebException ex2) ExceptionInfo = new(requestMessageInfo, ex2.FullMessage(), ex2.Status);
else if (exception is TaskCanceledException ex3 && ex3.InnerException is TimeoutException) ExceptionInfo = new(requestMessageInfo, ex3.InnerException.FullMessage(), WebExceptionStatus.Timeout);
else if (exception is TaskCanceledException ex4) ExceptionInfo = new(requestMessageInfo, ex4.FullMessage(), WebExceptionStatus.RequestCanceled);
else ExceptionInfo = new(requestMessageInfo, exception.FullMessage(), null);
}
public override string ToString() {
if (ResponseMessageInfo is object) {
var msg = ResponseMessageInfo.IsSuccessStatusCode ? "Success" : "Failure";
msg += $" {Enum.GetName(typeof(HttpStatusCode), ResponseMessageInfo.StatusCode)}";
if (ResponseMessageInfo.ReasonPhrase is object) msg += $" {ResponseMessageInfo.ReasonPhrase}";
return msg;
} else if (ExceptionInfo is object) {
var msg = "Failure";
msg += $" {ExceptionInfo.ErrorMessage}";
if (ExceptionInfo.WebExceptionStatus is object) msg += $" {Enum.GetName(typeof(WebExceptionStatus), ExceptionInfo.WebExceptionStatus)}";
return msg;
}
return "NA"; // never reach here
}
}
public static class ExtensionMethods {
// progressCallback recieves (bytesRecieved, percent, speedKbSec) and can return false to cancell download
public static async Task<(bool success, HttpResponse httpResponse)> DownloadFileAsync(this HttpClient httpClient, Uri requestUri, string fileToWriteTo, CancellationTokenSource? cts = null, Func<long, int, float, bool>? progressCallback = null) {
var httpRequestMessage = new HttpRequestMessage { Method = HttpMethod.Get, RequestUri = requestUri };
var created = false;
try {
var cancellationToken = cts?.Token ?? default;
using HttpResponseMessage httpResponseMessage = await httpClient.SendAsync(httpRequestMessage, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
if (!httpResponseMessage.IsSuccessStatusCode) return (false, new(httpRequestMessage, httpResponseMessage));
var contentLength = httpResponseMessage.Content.Headers.ContentLength;
using Stream streamToReadFrom = await httpResponseMessage.Content.ReadAsStreamAsync();
using Stream streamToWriteTo = File.Open(fileToWriteTo, FileMode.Create);
created = true;
var buffer = new byte[81920];
var bytesRecieved = (long)0;
var stopwatch = Stopwatch.StartNew();
int bytesInBuffer;
while ((bytesInBuffer = await streamToReadFrom.ReadAsync(buffer, cancellationToken)) != 0) {
await streamToWriteTo.WriteAsync(buffer.AsMemory(0, bytesInBuffer), cancellationToken);
bytesRecieved += bytesInBuffer;
if (progressCallback is object) {
var percent = contentLength is object && contentLength != 0 ? (int)Math.Floor(bytesRecieved / (float)contentLength * 100.0) : 0;
var speedKbSec = (float)((bytesRecieved / 1024.0) / (stopwatch.ElapsedMilliseconds / 1000.0));
var proceed = progressCallback(bytesRecieved, percent, speedKbSec);
if (!proceed) {
httpResponseMessage.ReasonPhrase = "Callback cancelled download";
httpResponseMessage.StatusCode = HttpStatusCode.PartialContent;
return (false, new(httpRequestMessage, httpResponseMessage));
}
}
}
return (true, new(httpRequestMessage, httpResponseMessage));
}
catch (Exception ex) {
if (created) try { File.Delete(fileToWriteTo); } catch { };
return (false, new(httpRequestMessage, ex));
}
}
public static async Task<(string? ResponseAsString, HttpResponse httpResponse)> GetToStringAsync(this HttpClient httpClient, Uri requestUri, CancellationTokenSource? cts = null) {
var httpRequestMessage = new HttpRequestMessage { Method = HttpMethod.Get, RequestUri = requestUri };
try {
var cancellationToken = cts?.Token ?? default;
using var httpResponseMessage = await httpClient.SendAsync(httpRequestMessage, cancellationToken);
if (!httpResponseMessage.IsSuccessStatusCode) return (null, new(httpRequestMessage, httpResponseMessage));
var responseAsString = await httpResponseMessage.Content.ReadAsStringAsync();
return (responseAsString, new(httpRequestMessage, httpResponseMessage));
}
catch (Exception ex) {
return (null, new(httpRequestMessage, ex)); ;
}
}
public static async Task<(string? ResponseAsString, HttpResponse httpResponse)> PostToStringAsync(this HttpClient httpClient, Uri requestUri, HttpContent postBuffer, CancellationTokenSource? cts = null) {
var httpRequestMessage = new HttpRequestMessage { Method = HttpMethod.Post, RequestUri = requestUri, Content = postBuffer };
try {
var cancellationToken = cts?.Token ?? default;
using var httpResponseMessage = await httpClient.SendAsync(httpRequestMessage, cancellationToken);
if (!httpResponseMessage.IsSuccessStatusCode) return (null, new(httpRequestMessage, httpResponseMessage));
var responseAsString = await httpResponseMessage.Content.ReadAsStringAsync();
return (responseAsString, new(httpRequestMessage, httpResponseMessage));
}
catch (Exception ex) {
return (null, new(httpRequestMessage, ex));
}
}
}
}
namespace System {
public static class ExtensionMethods {
public static string FullMessage(this Exception ex) {
if (ex is AggregateException aex) return aex.InnerExceptions.Aggregate("[ ", (total, next) => $"{total}[{next.FullMessage()}] ") + "]";
var msg = ex.Message.Replace(", see inner exception.", "").Trim();
var innerMsg = ex.InnerException?.FullMessage();
if (innerMsg is object && innerMsg!=msg) msg = $"{msg} [ {innerMsg} ]";
return msg;
}
}
}
To use:
// download to file
var lastPercent = 0;
bool progressCallback(long bytesRecieved, int percent, float speedKbSec) {
if (percent > lastPercent) {
lastPercent = percent;
Log($"Downloading... {percent}% {speedKbSec/1024.0:0.00}Mbps");
}
return true;
}
var (success, httpResponse) = await httpClient.DownloadFileAsync(
new(myUrlString),
localFileName,
null, // CancellationTokenSource
progressCallback
);
if (success) {
// file downloaded to localFile, httpResponse.ResponseMessageInfo contain
// extra information ie headers and status code
} else {
Log(httpResponse.ToString()); // human friendly error information
// if httpResponse.ResponseMessageInfo is object then server refused the request -
// examine httpResponse.ResponseMessageInfo.HttpStatusCode etc
// else we had a Http exception - examine httpResponse.ExceptionInfo
}
// Http get
var (responseAsString, httpResponse) = await httpClient.GetToStringAsync(url);
if (responseAsString is object) {
// responseAsString contains the string response from the server
} else {
// as for DownloadFileAsync
}
// http post
var postBuffer = new StringContent(jsonInString, System.Text.Encoding.UTF8, "application/x-www-form-urlencoded");
var (responseAsString, httpResponse) = await httpClient.PostToStringAsync(url, postBuffer);
if (responseAsString is object) {
// responseAsString contains the string response from the server
} else {
Log(httpResponse.ToString()); // human friendly error informaiton
// as for DownloadFileAsync
}
Below code contain logic for download file with original name
private string DownloadFile(string url)
{
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
string filename = "";
string destinationpath = Environment;
if (!Directory.Exists(destinationpath))
{
Directory.CreateDirectory(destinationpath);
}
using (HttpWebResponse response = (HttpWebResponse)request.GetResponseAsync().Result)
{
string path = response.Headers["Content-Disposition"];
if (string.IsNullOrWhiteSpace(path))
{
var uri = new Uri(url);
filename = Path.GetFileName(uri.LocalPath);
}
else
{
ContentDisposition contentDisposition = new ContentDisposition(path);
filename = contentDisposition.FileName;
}
var responseStream = response.GetResponseStream();
using (var fileStream = File.Create(System.IO.Path.Combine(destinationpath, filename)))
{
responseStream.CopyTo(fileStream);
}
}
return Path.Combine(destinationpath, filename);
}
There are a lot of answers but this is the solution I used recently for .NET 6 or greater.
using var httpClient = new HttpClient();
var tempPath = Path.GetTempFileName();
await using var s = await HttpClient.GetStreamAsync(pdfFilePath);
await using var fs = File.OpenWrite(tempPath);
await s.CopyToAsync(fs);
As per my research I found that WebClient.DownloadFileAsync is the best way to download file. It is available in System.Net namespace and it supports .net core as well.
Here is the sample code to download the file.
using System;
using System.IO;
using System.Net;
using System.ComponentModel;
public class Program
{
public static void Main()
{
new Program().Download("ftp://localhost/test.zip");
}
public void Download(string remoteUri)
{
string FilePath = Directory.GetCurrentDirectory() + "/tepdownload/" + Path.GetFileName(remoteUri); // path where download file to be saved, with filename, here I have taken file name from supplied remote url
using (WebClient client = new WebClient())
{
try
{
if (!Directory.Exists("tepdownload"))
{
Directory.CreateDirectory("tepdownload");
}
Uri uri = new Uri(remoteUri);
//password username of your file server eg. ftp username and password
client.Credentials = new NetworkCredential("username", "password");
//delegate method, which will be called after file download has been complete.
client.DownloadFileCompleted += new AsyncCompletedEventHandler(Extract);
//delegate method for progress notification handler.
client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(ProgessChanged);
// uri is the remote url where filed needs to be downloaded, and FilePath is the location where file to be saved
client.DownloadFileAsync(uri, FilePath);
}
catch (Exception)
{
throw;
}
}
}
public void Extract(object sender, AsyncCompletedEventArgs e)
{
Console.WriteLine("File has been downloaded.");
}
public void ProgessChanged(object sender, DownloadProgressChangedEventArgs e)
{
Console.WriteLine($"Download status: {e.ProgressPercentage}%.");
}
}
With above code file will be downloaded inside tepdownload folder of the project's directory. Please read comment in code to understand what above code do.
In the event that you need to set Headers and Cookies to download a file, you will need to do things slightly differently. Here is an example...
// Pass in the HTTPGET URL, Full Path w/Filename, and a populated Cookie Container (optional)
private async Task DownloadFileRequiringHeadersAndCookies(string getUrl, string fullPath, CookieContainer cookieContainer, CancellationToken cancellationToken)
{
cookieContainer ??= new CookieContainer(); // TODO: FILL ME AND PASS ME IN
using (var handler = new HttpClientHandler()
{
UseCookies = true,
CookieContainer = cookieContainer, // This will, both, use the cookies passed in, and update/create cookies from the response
ServerCertificateCustomValidationCallback = (message, cert, chain, errors) => true, // use only if it gets angry about the SSL endpoints
AllowAutoRedirect = true,
})
{
using (var client = new HttpClient(handler))
{
SetHeaders(client);
using (var response = await client.GetAsync(getUrl, cancellationToken))
{
if (response.IsSuccessStatusCode)
{
var bytes = await response.Content.ReadAsByteArrayAsync(cancellationToken);
await File.WriteAllBytesAsync(fullPath, bytes, cancellationToken); // This overwrites the file
}
else
{
// TODO: HANDLE ME
throw new FileNotFoundException();
}
}
}
}
}
And, to add the Headers you need with this...
private void SetHeaders(HttpClient client)
{
// TODO: SET ME
client.DefaultRequestHeaders.Connection.Add("keep-alive");
client.DefaultRequestHeaders.Add("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) ...");
client.DefaultRequestHeaders.Add("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9, ...");
client.DefaultRequestHeaders.AcceptEncoding.Add(new StringWithQualityHeaderValue("gzip"));
client.DefaultRequestHeaders.AcceptEncoding.Add(new StringWithQualityHeaderValue("deflate"));
client.DefaultRequestHeaders.AcceptLanguage.Add(new StringWithQualityHeaderValue("en-US"));
client.DefaultRequestHeaders.AcceptLanguage.Add(new StringWithQualityHeaderValue("en", .9));
...
}
ASIDE: You can fill the CookieContainer by:
Looping through the cookies of a previous Response.
This response could be from HttpAgilityPack, or WebClient, or Puppeteer (lots of options)
Manually entries (from config values or hard coded values).
You may need to know the status and update a ProgressBar during the file download or use credentials before making the request.
Here it is, an example that covers these options. Lambda notation and String interpolation has been used:
using System.Net;
// ...
using (WebClient client = new WebClient()) {
Uri ur = new Uri("http://remotehost.do/images/img.jpg");
//client.Credentials = new NetworkCredential("username", "password");
String credentials = Convert.ToBase64String(Encoding.ASCII.GetBytes("Username" + ":" + "MyNewPassword"));
client.Headers[HttpRequestHeader.Authorization] = $"Basic {credentials}";
client.DownloadProgressChanged += (o, e) =>
{
Console.WriteLine($"Download status: {e.ProgressPercentage}%.");
// updating the UI
Dispatcher.Invoke(() => {
progressBar.Value = e.ProgressPercentage;
});
};
client.DownloadDataCompleted += (o, e) =>
{
Console.WriteLine("Download finished!");
};
client.DownloadFileAsync(ur, #"C:\path\newImage.jpg");
}
static void Main(string[] args)
{
DownloadFileAsync().GetAwaiter();
Console.WriteLine("File was downloaded");
Console.Read();
}
private static async Task DownloadFileAsync()
{
WebClient client = new WebClient();
await client.DownloadFileTaskAsync(new Uri("http://somesite.com/myfile.txt"), "mytxtFile.txt");
}
This is my solution, it works fine:
public static void DownloadFile(string url, string pathToSaveFile)
{
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
// or: ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072;
using (WebDownload client = new WebDownload())
{
client.Headers["User-Agent"] = "User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36";
client.DownloadFile(new Uri(url), pathToSaveFile);
}
}
public class WebDownload : WebClient
{
protected override WebRequest GetWebRequest(Uri address)
{
HttpWebRequest request = (HttpWebRequest)base.GetWebRequest(address);
if (request != null)
{
request.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
}
return request;
}
}
In .NET Core MVC, you can sometimes do it as simply as:
public async Task<ActionResult> DownloadUrl(string url) {
return Redirect(url);
}
This probably assumes that the MIME type you're trying to download is set to be downloadable by the browser (e.g. .mp4), so it doesn't try to redirect to a webpage.