Implements a File Transfer Protocol (FTP) client.
Assembly: System (in System.dll)
Thetype exposes the following members.
|AuthenticationLevel||Gets or sets values indicating the level of authentication and impersonation used for this request. (Inherited from WebRequest.)|
|CachePolicy||Gets or sets the cache policy for this request. (Inherited from WebRequest.)|
|ClientCertificates||Gets or sets the certificates used for establishing an encrypted connection to the FTP server.|
|ConnectionGroupName||Gets or sets the name of the connection group that contains the service point used to send the current request. (Overrides WebRequest.ConnectionGroupName.)|
|ContentLength||Infrastructure. Gets or sets a value that is ignored by the class. (Overrides WebRequest.ContentLength.)|
|ContentOffset||Gets or sets a byte offset into the file being downloaded by this request.|
|ContentType||Infrastructure. Always throws a NotSupportedException. (Overrides WebRequest.ContentType.)|
|CreatorInstance||Obsolete. When overridden in a descendant class, gets the factory object derived from the IWebRequestCreate class used to create the WebRequest instantiated for making the request to the specified URI. (Inherited from WebRequest.)|
|Credentials||Gets or sets the credentials used to communicate with the FTP server. (Overrides WebRequest.Credentials.)|
|DefaultCachePolicy||Defines the default cache policy for all FTP requests.|
|EnableSsl||Gets or sets a Boolean that specifies that an SSL connection should be used.|
|Headers||Infrastructure. Gets an empty WebHeaderCollection object. (Overrides WebRequest.Headers.)|
|ImpersonationLevel||Gets or sets the impersonation level for the current request. (Inherited from WebRequest.)|
|KeepAlive||Gets or sets a Boolean value that specifies whether the control connection to the FTP server is closed after the request completes.|
|Method||Gets or sets the command to send to the FTP server. (Overrides WebRequest.Method.)|
|PreAuthenticate||Infrastructure. Always throws a NotSupportedException. (Overrides WebRequest.PreAuthenticate.)|
|Proxy||Gets or sets the proxy used to communicate with the FTP server. (Overrides WebRequest.Proxy.)|
|ReadWriteTimeout||Gets or sets a time-out when reading from or writing to a stream.|
|RenameTo||Gets or sets the new name of a file being renamed.|
|RequestUri||Gets the URI requested by this instance. (Overrides WebRequest.RequestUri.)|
|ServicePoint||Gets the ServicePoint object used to connect to the FTP server.|
|Timeout||Gets or sets the number of milliseconds to wait for a request. (Overrides WebRequest.Timeout.)|
|UseBinary||Gets or sets a Boolean value that specifies the data type for file transfers.|
|UseDefaultCredentials||Infrastructure. Always throws a NotSupportedException. (Overrides WebRequest.UseDefaultCredentials.)|
|UsePassive||Gets or sets the behavior of a client application's data transfer process.|
|Abort||Terminates an asynchronous FTP operation. (Overrides WebRequest.Abort.)|
|BeginGetRequestStream||Begins asynchronously opening a request's content stream for writing. (Overrides WebRequest.BeginGetRequestStream(AsyncCallback, Object).)|
|BeginGetResponse||Begins sending a request and receiving a response from an FTP server asynchronously. (Overrides WebRequest.BeginGetResponse(AsyncCallback, Object).)|
|CreateObjRef||Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object. (Inherited from MarshalByRefObject.)|
|EndGetRequestStream||Ends a pending asynchronous operation started with BeginGetRequestStream. (Overrides WebRequest.EndGetRequestStream(IAsyncResult).)|
|EndGetResponse||Ends a pending asynchronous operation started with BeginGetResponse. (Overrides WebRequest.EndGetResponse(IAsyncResult).)|
|Equals(Object)||Determines whether the specified object is equal to the current object. (Inherited from Object.)|
|GetHashCode||Serves as the default hash function. (Inherited from Object.)|
|GetLifetimeService||Retrieves the current lifetime service object that controls the lifetime policy for this instance. (Inherited from MarshalByRefObject.)|
|GetRequestStream||Retrieves the stream used to upload data to an FTP server. (Overrides WebRequest.GetRequestStream.)|
|GetRequestStreamAsync||When overridden in a descendant class, returns a Stream for writing data to the Internet resource as an asynchronous operation. (Inherited from WebRequest.)|
|GetResponse||Returns the FTP server response. (Overrides WebRequest.GetResponse.)|
|GetResponseAsync||When overridden in a descendant class, returns a response to an Internet request as an asynchronous operation. (Inherited from WebRequest.)|
|GetType||Gets the Type of the current instance. (Inherited from Object.)|
|InitializeLifetimeService||Obtains a lifetime service object to control the lifetime policy for this instance. (Inherited from MarshalByRefObject.)|
|ToString||Returns a string that represents the current object. (Inherited from Object.)|
To obtain an instance of , use the Create method. You can also use the WebClient class to upload and download information from an FTP server. Using either of these approaches, when you specify a network resource that uses the FTP scheme (for example, "ftp://contoso.com") the class provides the ability to programmatically interact with FTP servers.
The URI may be relative or absolute. If the URI is of the form "ftp://contoso.com/%2fpath" (%2f is an escaped '/'), then the URI is absolute, and the current directory is /path. If, however, the URI is of the form "ftp://contoso.com/path", first the .NET Framework logs into the FTP server (using the user name and password set by the Credentials property), then the current directory is set to <UserLoginDirectory>/path.
You must have a valid user name and password for the server or the server must allow anonymous logon. You can specify the credentials used to connect to the server by setting the Credentials property or you can include them in the UserInfo portion of the URI passed to the Create method. If you include UserInfo information in the URI, the Credentials property is set to a new network credential with the specified user name and password information.
Unless the EnableSsl property is true, all data and commands, including your user name and password information, are sent to the server in clear text. Anyone monitoring network traffic can view your credentials and use them to connect to the server. If you are connecting to an FTP server that requires credentials and supports Secure Sockets Layer (SSL), you should set EnableSsl to true.
Specify the FTP command to send to the server by setting the Method property to a value defined in the WebRequestMethods.Ftp structure. To transmit text data, change the UseBinary property from its default value (true) to false. For details and restrictions, see Method.
When using an object to upload a file to a server, you must write the file content to the request stream obtained by calling the GetRequestStream method or its asynchronous counterparts, the BeginGetRequestStream and EndGetRequestStream methods. You must write to the stream and close the stream before sending the request.
Requests are sent to the server by calling the GetResponse method or its asynchronous counterparts, the BeginGetResponse and EndGetResponse methods. When the requested operation completes, an FtpWebResponse object is returned. The FtpWebResponse object provides the status of the operation and any data downloaded from the server.
You can set a time-out value for reading or writing to the server by using the ReadWriteTimeout property. If the time-out period is exceeded, the calling method throws a WebException with WebExceptionStatus set to Timeout.
When downloading a file from an FTP server, if the command was successful, the contents of the requested file are available in the response object's stream. You can access this stream by calling the GetResponseStream method. For more information, see FtpWebResponse.
If the Proxy property is set, either directly or in a configuration file, communications with the FTP server are made through the specified proxy. If the specified proxy is an HTTP proxy, only the DownloadFile, ListDirectory, and ListDirectoryDetails commands are supported.
Multiple s reuse existing connections, if possible.
For more information about the FTP protocol, see RFC 959, "File Transfer Protocol," available at http://www.rfc-editor.org/.
The following code example demonstrates deleting a file from an FTP server.
The following code example demonstrates downloading a file from an FTP server by using the WebClient class.
The following code example demonstrates using asynchronous operations to upload a file to an FTP server.