System.Net.WebClient Class

Provides a simple way to send data to and retrieve data from a resource identified by a URI.

Namespace

Syntax

public class WebClient : Component

Remarks

The WebClient class provides easy access to resources over HTTP, FTP, and File protocols. It simplifies common tasks such as downloading files, uploading data, and making asynchronous requests.

This class is thread-safe. You can use multiple instances of WebClient in a single thread, or you can use a single instance in multiple threads.

For more advanced scenarios, consider using HttpClient.

Members

Constructors

WebClient()
Initializes a new instance of the WebClient class.

Methods

DownloadFile(string address, string fileName)
public virtual void DownloadFile(string address, string fileName);

Downloads the resource with the specified URI to a local file.

// Example: Download a file WebClient client = new WebClient(); try { client.DownloadFile("http://example.com/data.zip", "downloaded_data.zip"); Console.WriteLine("File downloaded successfully."); } catch (Exception ex) { Console.WriteLine("Error downloading file: " + ex.Message); }
DownloadString(string address)
public virtual string DownloadString(string address);

Returns the response body as a string from the specified URI.

// Example: Download a string WebClient client = new WebClient(); try { string html = client.DownloadString("http://example.com"); Console.WriteLine("HTML content length: " + html.Length); } catch (Exception ex) { Console.WriteLine("Error downloading string: " + ex.Message); }
UploadFile(string address, string fileName)
public virtual byte[] UploadFile(string address, string fileName);

Uploads the specified local file to the specified resource.

// Example: Upload a file WebClient client = new WebClient(); try { byte[] responseBytes = client.UploadFile("http://example.com/upload", "local_file.txt"); string responseString = System.Text.Encoding.ASCII.GetString(responseBytes); Console.WriteLine("Upload response: " + responseString); } catch (Exception ex) { Console.WriteLine("Error uploading file: " + ex.Message); }
UploadString(string address, string data)
public virtual string UploadString(string address, string data);

Uploads the specified string to the specified resource.

// Example: Upload a string WebClient client = new WebClient(); try { string response = client.UploadString("http://example.com/submit", "This is my data."); Console.WriteLine("Upload string response: " + response); } catch (Exception ex) { Console.WriteLine("Error uploading string: " + ex.Message); }
DownloadFileAsync(Uri address, string fileName)
public virtual void DownloadFileAsync(Uri address, string fileName);

Initiates an asynchronous operation to download the resource with the specified URI to a local file.
DownloadStringAsync(Uri address)
public virtual void DownloadStringAsync(Uri address);

Initiates an asynchronous operation to download the resource with the specified URI.
UploadFileAsync(Uri address, string fileName)
public virtual void UploadFileAsync(Uri address, string fileName);

Initiates an asynchronous operation to upload the specified local file to the specified resource.
UploadStringAsync(Uri address, string data)
public virtual void UploadStringAsync(Uri address, string data);

Initiates an asynchronous operation to upload the specified string to the specified resource.

Properties

BaseAddress
public virtual string BaseAddress { get; set; }

Gets or sets the base address of the Uniform Resource Identifier (URI) that is used for requests.
Encoding
public virtual System.Text.Encoding Encoding { get; set; }

Gets or sets the encoding that is used to upload and download text.
Headers
public virtual System.Net.WebHeaderCollection Headers { get; }

Gets the collection of HTTP headers associated with the request.
IsBusy
public bool IsBusy { get; }

Gets a value indicating whether the asynchronous operation is in progress.
QueryString
public virtual System.Collections.Specialized.NameValueCollection QueryString { get; set; }

Gets or sets the query string parameters to append to the URI.

Events

DownloadFileCompleted
public event System.Net.DownloadFileCompletedEventHandler DownloadFileCompleted;

Occurs when a file transfer is completed.
DownloadProgressChanged
public event System.Net.DownloadProgressChangedEventHandler DownloadProgressChanged;

Occurs when the progress of an asynchronous file transfer is updated.
UploadFileCompleted
public event System.Net.UploadFileCompletedEventHandler UploadFileCompleted;

Occurs when a file upload is completed.
UploadProgressChanged
public event System.Net.UploadProgressChangedEventHandler UploadProgressChanged;

Occurs when the progress of an asynchronous file upload is updated.