TFTPClient Component

Properties   Methods   Events   Config Settings   Errors  

The TFTPClient component is used to exchange files with TFTP servers via the TFTP protocol defined in RFC 783.

Syntax

nsoftware.IPWorks.TFTPClient

Remarks

To use the component, first specify the TFTPServer, then a LocalFile and a RemoteFile, and then call GetFile or PutFile. The Transfer event shows the progress of the transfer.

Potential transmission errors and packet loss are managed by the Timeout property, which controls the maximum time to wait for a response from the server, and the MaxRetransmits property, which specifies how many times to resend a failed packet before giving up.

Property List

The following is the full list of the properties of the component with short descriptions. Click on the links for further details.

Method List

The following is the full list of the methods of the component with short descriptions. Click on the links for further details.

Event List

The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.

Config Settings

The following is a list of config settings for the component with short descriptions. Click on the links for further details.

Idle Property (TFTPClient Component)

The current status of the component.

Syntax

• C#
• VB.NET

public bool Idle { get; }

Public ReadOnly Property Idle As Boolean

Default Value

True

Remarks

This property will be False if the component is currently busy (communicating or waiting for an answer), and True at all other times.

This property is read-only.

LocalFile Property (TFTPClient Component)

This property includes a file on the local host to transfer the data to or from.

Syntax

• C#
• VB.NET

public string LocalFile { get; set; }

Public Property LocalFile As String

Default Value

""

Remarks

If GetFile is called, and LocalFile already exists, it is overwritten. If PutFile is called, LocalFile must point to a valid file or an error will be returned.

LocalHost Property (TFTPClient Component)

The name of the local host or user-assigned IP interface through which connections are initiated or accepted.

Syntax

• C#
• VB.NET

public string LocalHost { get; set; }

Public Property LocalHost As String

Default Value

""

Remarks

This property contains the name of the local host as obtained by the gethostname() system call, or if the user has assigned an IP address, the value of that address.

In multihomed hosts (machines with more than one IP interface) setting LocalHost to the IP address of an interface will make the component initiate connections (or accept in the case of server components) only through that interface. It is recommended to provide an IP address rather than a hostname when setting this property to ensure the desired interface is used.

If the component is connected, the LocalHost property shows the IP address of the interface through which the connection is made in internet dotted format (aaa.bbb.ccc.ddd). In most cases, this is the address of the local host, except for multihomed hosts (machines with more than one IP interface).

Note: LocalHost is not persistent. You must always set it in code, and never in the property window.

MaxRetransmits Property (TFTPClient Component)

This property specifies the number of times to retry sending a failed packet before disconnecting.

Syntax

• C#
• VB.NET

public int MaxRetransmits { get; set; }

Public Property MaxRetransmits As Integer

Default Value

3

Remarks

This property allows you to specify the number of times that you would like to try resending the last data packet if the original packet fails.

The RetransmitTimeout determines the wait time (in seconds) between successive retransmissions.

The default value for the MaxRetransmits property is 3.

RemoteFile Property (TFTPClient Component)

This property includes the file on the remote host.

Syntax

• C#
• VB.NET

public string RemoteFile { get; set; }

Public Property RemoteFile As String

Default Value

""

Remarks

When the GetFile is called, this must be a valid file on the TFTPServer.

RetransmitTimeout Property (TFTPClient Component)

This property includes the maximum time in seconds to wait for a reply packet from the server before retransmitting the last packet.

Syntax

• C#
• VB.NET

public int RetransmitTimeout { get; set; }

Public Property RetransmitTimeout As Integer

Default Value

5

Remarks

Please refer to the MaxRetransmits property for the number of retransmit efforts before an error is returned.

The default value for the RetransmitTimeout is 5 seconds.

TFTPPort Property (TFTPClient Component)

This property specifies the User Datagram Protocol (UDP) port where the remote TFTP server is listening.

Syntax

• C#
• VB.NET

public int TFTPPort { get; set; }

Public Property TFTPPort As Integer

Default Value

69

Remarks

The TFTPPort is the UDP port on the TFTPServer to send TFTP requests to.

This property is not available at design time.

TFTPServer Property (TFTPClient Component)

This property includes the address of the TFTP server to exchange files with.

Syntax

• C#
• VB.NET

public string TFTPServer { get; set; }

Public Property TFTPServer As String

Default Value

""

Remarks

To be able to transfer file via TFTP, the remote host must be running TFTP services on port TFTPPort (default 69).

Example. Get a File:

TFTPControl.TFTPServer = "MyServer" TFTPControl.LocalFile = "C:\filename.txt" TFTPControl.RemoteFile = "/remotefile.txt" TFTPControl.GetFile()

Timeout Property (TFTPClient Component)

The timeout for the component.

Syntax

• C#
• VB.NET

public int Timeout { get; set; }

Public Property Timeout As Integer

Default Value

60

Remarks

If the Timeout property is set to 0, all operations will run uninterrupted until successful completion or an error condition is encountered.

If Timeout is set to a positive value, the component will wait for the operation to complete before returning control.

The component will use DoEvents to enter an efficient wait loop during any potential waiting period, making sure that all system events are processed immediately as they arrive. This ensures that the host application does not freeze and remains responsive.

If Timeout expires, and the operation is not yet complete, the component throws an exception.

Note: By default, all timeouts are inactivity timeouts, that is, the timeout period is extended by Timeout seconds when any amount of data is successfully sent or received.

The default value for the Timeout property is 60 seconds.

Config Method (TFTPClient Component)

Sets or retrieves a configuration setting.

Syntax

• C#
• VB.NET

public string Config(string configurationString);

Async Version
public async Task<string> Config(string configurationString);
public async Task<string> Config(string configurationString, CancellationToken cancellationToken);

Public Function Config(ByVal ConfigurationString As String) As String

Async Version
Public Function Config(ByVal ConfigurationString As String) As Task(Of String)
Public Function Config(ByVal ConfigurationString As String, cancellationToken As CancellationToken) As Task(Of String)

Remarks

Config is a generic method available in every component. It is used to set and retrieve configuration settings for the component.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

DoEvents Method (TFTPClient Component)

This method processes events from the internal message queue.

Syntax

• C#
• VB.NET

public void DoEvents();

Async Version
public async Task DoEvents();
public async Task DoEvents(CancellationToken cancellationToken);

Public Sub DoEvents()

Async Version
Public Sub DoEvents() As Task
Public Sub DoEvents(cancellationToken As CancellationToken) As Task

Remarks

When DoEvents is called, the component processes any available events. If no events are available, it waits for a preset period of time, and then returns.

GetFile Method (TFTPClient Component)

This method downloads a RemoteFile from the TFTP server.

Syntax

• C#
• VB.NET

public void GetFile();

Async Version
public async Task GetFile();
public async Task GetFile(CancellationToken cancellationToken);

Public Sub GetFile()

Async Version
Public Sub GetFile() As Task
Public Sub GetFile(cancellationToken As CancellationToken) As Task

Remarks

The remote file specified by RemoteFile is downloaded to the local file specified by LocalFile, or it is retrieved through the Transfer event, if the LocalFile property is "" (empty string).

Example. Get a File:

TFTPControl.TFTPServer = "MyServer" TFTPControl.LocalFile = "C:\filename.txt" TFTPControl.RemoteFile = "/remotefile.txt" TFTPControl.GetFile()

Interrupt Method (TFTPClient Component)

This method interrupts the current method.

Syntax

• C#
• VB.NET

public void Interrupt();

Async Version
public async Task Interrupt();
public async Task Interrupt(CancellationToken cancellationToken);

Public Sub Interrupt()

Async Version
Public Sub Interrupt() As Task
Public Sub Interrupt(cancellationToken As CancellationToken) As Task

Remarks

If there is no method in progress, Interrupt simply returns, doing nothing.

PutFile Method (TFTPClient Component)

This method uploads a file specified by LocalFile to the TFTP server.

Syntax

• C#
• VB.NET

public void PutFile();

Async Version
public async Task PutFile();
public async Task PutFile(CancellationToken cancellationToken);

Public Sub PutFile()

Async Version
Public Sub PutFile() As Task
Public Sub PutFile(cancellationToken As CancellationToken) As Task

Remarks

The local file specified by LocalFile is uploaded to the remote file specified by RemoteFile.

Example. Put a File:

TFTPControl.TFTPServer = "MyServer" TFTPControl.LocalFile = "C:\filename.txt" TFTPControl.RemoteFile = "/remotefile.txt" TFTPControl.PutFile()

Reset Method (TFTPClient Component)

This method resets the component.

Syntax

• C#
• VB.NET

public void Reset();

Async Version
public async Task Reset();
public async Task Reset(CancellationToken cancellationToken);

Public Sub Reset()

Async Version
Public Sub Reset() As Task
Public Sub Reset(cancellationToken As CancellationToken) As Task

Remarks

This method will reset the component's properties to their default values.

SetDownloadStream Method (TFTPClient Component)

This method sets the stream to which the downloaded data from the server will be written.

Syntax

• C#
• VB.NET

public void SetDownloadStream(System.IO.Stream downloadStream);

Async Version
public async Task SetDownloadStream(System.IO.Stream downloadStream);
public async Task SetDownloadStream(System.IO.Stream downloadStream, CancellationToken cancellationToken);

Public Sub SetDownloadStream(ByVal DownloadStream As System.IO.Stream)

Async Version
Public Sub SetDownloadStream(ByVal DownloadStream As System.IO.Stream) As Task
Public Sub SetDownloadStream(ByVal DownloadStream As System.IO.Stream, cancellationToken As CancellationToken) As Task

Remarks

If a download stream is set before the GetFile method is called, the downloaded data will be written to the stream. The stream should be open and normally set to position 0. The component will automatically close this stream if CloseStreamAfterTransfer is set to True (default). If the stream is closed, you will need to call SetDownloadStream again before calling GetFile again. The downloaded content will be written starting at the current position in the stream.

Note: SetDownloadStream and LocalFile will reset the other.

SetUploadStream Method (TFTPClient Component)

This method sets the stream to be uploaded to the server.

Syntax

• C#
• VB.NET

public void SetUploadStream(System.IO.Stream uploadStream);

Async Version
public async Task SetUploadStream(System.IO.Stream uploadStream);
public async Task SetUploadStream(System.IO.Stream uploadStream, CancellationToken cancellationToken);

Public Sub SetUploadStream(ByVal UploadStream As System.IO.Stream)

Async Version
Public Sub SetUploadStream(ByVal UploadStream As System.IO.Stream) As Task
Public Sub SetUploadStream(ByVal UploadStream As System.IO.Stream, cancellationToken As CancellationToken) As Task

Remarks

If an upload stream is set before the PutFile method is called, the content of the stream will be read by the component and uploaded to the server; The stream should be open and normally set to position 0. The component will automatically close this stream if CloseStreamAfterTransfer is set to True (default). If the stream is closed, you will need to call SetUploadStream again before calling PutFile again. The content of the stream will be read from the current position all the way to the end.

Note: SetUploadStream and LocalFile will reset the other.

EndTransfer Event (TFTPClient Component)

This event is fired when a file finishes downloading or uploading.

Syntax

• C#
• VB.NET

public event OnEndTransferHandler OnEndTransfer;

public delegate void OnEndTransferHandler(object sender, TFTPClientEndTransferEventArgs e);

public class TFTPClientEndTransferEventArgs : EventArgs {
  public int Direction { get; }
}

Public Event OnEndTransfer As OnEndTransferHandler

Public Delegate Sub OnEndTransferHandler(sender As Object, e As TFTPClientEndTransferEventArgs)

Public Class TFTPClientEndTransferEventArgs Inherits EventArgs
  Public ReadOnly Property Direction As Integer
End Class

Remarks

The EndTransfer event fires when a Data Interface connection is closed. This occurs when the file finishes transferring or a directory listing is finished.

The Direction parameter shows whether the client (0) or the server (1) is sending the data.

Error Event (TFTPClient Component)

Fired when information is available about errors during data delivery.

Syntax

• C#
• VB.NET

public event OnErrorHandler OnError;

public delegate void OnErrorHandler(object sender, TFTPClientErrorEventArgs e);

public class TFTPClientErrorEventArgs : EventArgs {
  public int ErrorCode { get; }
  public string Description { get; }
}

Public Event OnError As OnErrorHandler

Public Delegate Sub OnErrorHandler(sender As Object, e As TFTPClientErrorEventArgs)

Public Class TFTPClientErrorEventArgs Inherits EventArgs
  Public ReadOnly Property ErrorCode As Integer
  Public ReadOnly Property Description As String
End Class

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the component throws an exception.

The ErrorCode parameter contains an error code, and the Description parameter contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

StartTransfer Event (TFTPClient Component)

This event fires when a file starts downloading or uploading.

Syntax

• C#
• VB.NET

public event OnStartTransferHandler OnStartTransfer;

public delegate void OnStartTransferHandler(object sender, TFTPClientStartTransferEventArgs e);

public class TFTPClientStartTransferEventArgs : EventArgs {
  public int Direction { get; }
}

Public Event OnStartTransfer As OnStartTransferHandler

Public Delegate Sub OnStartTransferHandler(sender As Object, e As TFTPClientStartTransferEventArgs)

Public Class TFTPClientStartTransferEventArgs Inherits EventArgs
  Public ReadOnly Property Direction As Integer
End Class

Remarks

The StartTransfer event fires when a Data Interface connection is created. This is when the file starts transferring or a directory listing is started.

The Direction parameter shows whether the client (0) or the server (1) is sending the data.

Transfer Event (TFTPClient Component)

This event is fired during the file download or upload.

Syntax

• C#
• VB.NET

public event OnTransferHandler OnTransfer;

public delegate void OnTransferHandler(object sender, TFTPClientTransferEventArgs e);

public class TFTPClientTransferEventArgs : EventArgs {
  public int Direction { get; }
  public long BytesTransferred { get; }
  public int PercentDone { get; }
  public string Text { get; }
  public byte[] TextB { get; }
}

Public Event OnTransfer As OnTransferHandler

Public Delegate Sub OnTransferHandler(sender As Object, e As TFTPClientTransferEventArgs)

Public Class TFTPClientTransferEventArgs Inherits EventArgs
  Public ReadOnly Property Direction As Integer
  Public ReadOnly Property BytesTransferred As Long
  Public ReadOnly Property PercentDone As Integer
  Public ReadOnly Property Text As String
  Public ReadOnly Property TextB As Byte()
End Class

Remarks

One or more Transfer events are fired during file transfer. The BytesTransferred parameter shows the number of bytes transferred since the beginning of the transfer.

Text contains the portion of the file data being delivered.

The Direction parameter shows whether the client (0) or the server (1) is sending the data.

The PercentDone parameter shows the progress of the transfer in the corresponding direction. If PercentDone can not be calculated the value will be -1.

Note: Events are not re-entrant. Performing time-consuming operations within this event will prevent it from firing again in a timely manner and may affect overall performance.

Config Settings (TFTPClient Component)

TFTPClient Config Settings

UDP Config Settings

Socket Config Settings

Base Config Settings

Trappable Errors (TFTPClient Component)

TFTPClient Errors

The component may also return one of the following error codes, which are inherited from other components.

UDP Errors

SSL Errors

TCP/IP Errors