WebClient.OpenWrite Method

Reference

Definition

Namespace:: System.Net

Assemblies:: netstandard.dll, System.Net.WebClient.dll

Assembly:: System.Net.WebClient.dll

Assembly:: System.dll

Assembly:: netstandard.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Opens a stream for writing data to a resource with the specified URI.

Overloads

OpenWrite(String)	Opens a stream for writing data to the specified resource.
OpenWrite(Uri)	Opens a stream for writing data to the specified resource.
OpenWrite(String, String)	Opens a stream for writing data to the specified resource, using the specified method.
OpenWrite(Uri, String)	Opens a stream for writing data to the specified resource, by using the specified method.

OpenWrite(String)

Source:: WebClient.cs

Source:: WebClient.cs

Source:: WebClient.cs

Opens a stream for writing data to the specified resource.

public:
 System::IO::Stream ^ OpenWrite(System::String ^ address);

public System.IO.Stream OpenWrite(string address);

member this.OpenWrite : string -> System.IO.Stream

Public Function OpenWrite (address As String) As Stream

Parameters

address: String

The URI of the resource to receive the data.

Returns

Stream

A Stream used to write data to the resource.

Exceptions

ArgumentNullException

The address parameter is null.

WebException

The URI formed by combining BaseAddress, and address is invalid.

-or-

An error occurred while opening the stream.

Examples

The following code example reads data from the command line and uses OpenWrite to obtain a stream for writing the data. The Stream returned by OpenWrite is closed after the data is sent.

String^ uriString;
Console::Write( "\nPlease enter the URI to post data to: " );
uriString = Console::ReadLine();
Console::WriteLine( "\nPlease enter the data to be posted to the URI {0}:", uriString );
String^ postData = Console::ReadLine();
// Apply Ascii Encoding to obtain an array of bytes.
array<Byte>^ postArray = Encoding::ASCII->GetBytes( postData );

// Create a new WebClient instance.
WebClient^ myWebClient = gcnew WebClient;

// postStream implicitly sets HTTP POST as the request method.
Console::WriteLine( "Uploading to {0} ...", uriString );
Stream^ postStream = myWebClient->OpenWrite( uriString );

postStream->Write( postArray, 0, postArray->Length );

// Close the stream and release resources.
postStream->Close();

Console::WriteLine( "\nSuccessfully posted the data." );

string uriString;
Console.Write("\nPlease enter the URI to post data to : ");
uriString = Console.ReadLine();
Console.WriteLine("\nPlease enter the data to be posted to the URI {0}:",uriString);
string postData = Console.ReadLine();
// Apply Ascii Encoding to obtain an array of bytes. 
byte[] postArray = Encoding.ASCII.GetBytes(postData);

// Create a new WebClient instance.
WebClient myWebClient = new WebClient();

// postStream implicitly sets HTTP POST as the request method.
Console.WriteLine("Uploading to {0} ...",  uriString);							Stream postStream = myWebClient.OpenWrite(uriString);

postStream.Write(postArray,0,postArray.Length);

// Close the stream and release resources.
postStream.Close();

Console.WriteLine("\nSuccessfully posted the data.");

Dim uriString As String
Console.Write(ControlChars.Cr + "Please enter the URI to post data to : ")
uriString = Console.ReadLine()
Console.WriteLine(ControlChars.Cr + "Please enter the data to be posted to the URI {0}:", uriString)

Dim postData As String = Console.ReadLine()

' Apply ASCII Encoding to obtain an array of bytes .
Dim postArray As Byte() = Encoding.ASCII.GetBytes(postData)

' Create a new WebClient instance.
Dim myWebClient As New WebClient()

Console.WriteLine("Uploading to {0} ...", uriString)

' OpenWrite implicitly sets HTTP POST as the request method.
Dim postStream As Stream = myWebClient.OpenWrite(uriString)
postStream.Write(postArray, 0, postArray.Length)

' Close the stream and release resources.
postStream.Close()

Console.WriteLine(ControlChars.Cr + "Successfully posted the data.")

Remarks

Caution

WebRequest, HttpWebRequest, ServicePoint, and WebClient are obsolete, and you shouldn't use them for new development. Use HttpClient instead.

The OpenWrite method returns a writable stream that is used to send data to a resource. This method blocks while opening the stream. To continue executing while waiting for the stream, use one of the OpenWriteAsync methods.

If the BaseAddress property is not an empty string ("") and address does not contain an absolute URI, address must be a relative URI that is combined with BaseAddress to form the absolute URI of the requested data. If the QueryString property is not an empty string, it is appended to address.

This method uses the STOR command to upload an FTP resource. For an HTTP resource, the POST method is used.

Note

This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing in .NET Framework.

Applies to

.NET 10 and other versions

Product	Versions
.NET	Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10
.NET Framework	1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard	2.0, 2.1

OpenWrite(Uri)

Source:: WebClient.cs

Source:: WebClient.cs

Source:: WebClient.cs

Opens a stream for writing data to the specified resource.

public:
 System::IO::Stream ^ OpenWrite(Uri ^ address);

public System.IO.Stream OpenWrite(Uri address);

member this.OpenWrite : Uri -> System.IO.Stream

Public Function OpenWrite (address As Uri) As Stream

Parameters

address: Uri

The URI of the resource to receive the data.

Returns

Stream

A Stream used to write data to the resource.

Exceptions

ArgumentNullException

The address parameter is null.

WebException

The URI formed by combining BaseAddress, and address is invalid.

-or-

An error occurred while opening the stream.

Remarks

Caution

WebRequest, HttpWebRequest, ServicePoint, and WebClient are obsolete, and you shouldn't use them for new development. Use HttpClient instead.

This method uses the STOR command to upload an FTP resource. For an HTTP resource, the POST method is used.

Note

This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing in .NET Framework.

Applies to

.NET 10 and other versions

Product	Versions
.NET	Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10
.NET Framework	2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard	2.0, 2.1

OpenWrite(String, String)

Source:: WebClient.cs

Source:: WebClient.cs

Source:: WebClient.cs

Opens a stream for writing data to the specified resource, using the specified method.

public:
 System::IO::Stream ^ OpenWrite(System::String ^ address, System::String ^ method);

public System.IO.Stream OpenWrite(string address, string? method);

public System.IO.Stream OpenWrite(string address, string method);

member this.OpenWrite : string * string -> System.IO.Stream

Public Function OpenWrite (address As String, method As String) As Stream

Parameters

address: String

The URI of the resource to receive the data.

method: String

The method used to send the data to the resource. If null, the default is POST for http and STOR for ftp.

Returns

Stream

A Stream used to write data to the resource.

Exceptions

ArgumentNullException

The address parameter is null.

WebException

The URI formed by combining BaseAddress, and address is invalid.

-or-

An error occurred while opening the stream.

Examples

The following code example reads data from the command line and uses OpenWrite to obtain a stream used to write the data. The Stream returned by OpenWrite must be closed to send the data.

String^ uriString;
Console::Write( "\nPlease enter the URI to post data to: " );
uriString = Console::ReadLine();
Console::WriteLine( "\nPlease enter the data to be posted to the URI {0}:", uriString );
String^ postData = Console::ReadLine();
// Apply ASCII encoding to obtain an array of bytes .
array<Byte>^ postArray = Encoding::ASCII->GetBytes( postData );

// Create a new WebClient instance.
WebClient^ myWebClient = gcnew WebClient;

Console::WriteLine( "Uploading to {0} ...", uriString );
Stream^ postStream = myWebClient->OpenWrite( uriString, "POST" );
postStream->Write( postArray, 0, postArray->Length );

// Close the stream and release resources.
postStream->Close();
Console::WriteLine( "\nSuccessfully posted the data." );

string uriString;
Console.Write("\nPlease enter the URI to post data to : ");
uriString = Console.ReadLine();
Console.WriteLine("\nPlease enter the data to be posted to the URI {0}:",uriString);
string postData = Console.ReadLine();
// Apply ASCII encoding to obtain an array of bytes .
byte[] postArray = Encoding.ASCII.GetBytes(postData);

// Create a new WebClient instance.
WebClient myWebClient = new WebClient();

Console.WriteLine("Uploading to {0} ...",  uriString);						
Stream postStream = myWebClient.OpenWrite(uriString,"POST");
postStream.Write(postArray,0,postArray.Length);

// Close the stream and release resources.
postStream.Close();
Console.WriteLine("\nSuccessfully posted the data.");

Dim uriString As String
Console.Write(ControlChars.Cr + "Please enter the URI to post data to : ")
uriString = Console.ReadLine()
Console.WriteLine(ControlChars.Cr + "Please enter the data to be posted to the URI {0}:", uriString)
Dim postData As String = Console.ReadLine()
' Apply ASCII encoding to obtain an array of bytes.
Dim postArray As Byte() = Encoding.ASCII.GetBytes(postData)

' Create a new WebClient instance.
Dim myWebClient As New WebClient()

Console.WriteLine("Uploading to {0} ...", uriString)
Dim postStream As Stream = myWebClient.OpenWrite(uriString, "POST")

postStream.Write(postArray, 0, postArray.Length)

' Close the stream and release resources.
postStream.Close()

Console.WriteLine(ControlChars.Cr + "Successfully posted the data.")

Remarks

Caution

WebRequest, HttpWebRequest, ServicePoint, and WebClient are obsolete, and you shouldn't use them for new development. Use HttpClient instead.

The OpenWrite method returns a writable stream that is used to send data to a resource. The underlying request is made with the method specified in the method parameter. The data is sent to the server when you close the stream. This method blocks while opening the stream. To continue executing while waiting for the stream, use one of the OpenWriteAsync methods.

If the method parameter specifies a method that is not understood by the server, the underlying protocol classes determine what occurs. Typically, a WebException is thrown with the Status property set to indicate the error.

If the BaseAddress property is not an empty string ("") and address does not specify an absolute address, address must be a relative URI that is combined with BaseAddress to form the absolute URI of the requested data. If the QueryString property is not an empty string, it is appended to address.

Note

This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing in .NET Framework.

Applies to

.NET 10 and other versions

Product	Versions
.NET	Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10
.NET Framework	1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard	2.0, 2.1

OpenWrite(Uri, String)

Source:: WebClient.cs

Source:: WebClient.cs

Source:: WebClient.cs

Opens a stream for writing data to the specified resource, by using the specified method.

public:
 System::IO::Stream ^ OpenWrite(Uri ^ address, System::String ^ method);

public System.IO.Stream OpenWrite(Uri address, string? method);

public System.IO.Stream OpenWrite(Uri address, string method);

member this.OpenWrite : Uri * string -> System.IO.Stream

Public Function OpenWrite (address As Uri, method As String) As Stream

Parameters

address: Uri

The URI of the resource to receive the data.

method: String

The method used to send the data to the resource. If null, the default is POST for http and STOR for ftp.

Returns

Stream

A Stream used to write data to the resource.

Exceptions

ArgumentNullException

The address parameter is null.

WebException

The URI formed by combining BaseAddress, and address is invalid.

-or-

An error occurred while opening the stream.

Remarks

Caution

WebRequest, HttpWebRequest, ServicePoint, and WebClient are obsolete, and you shouldn't use them for new development. Use HttpClient instead.

Note

This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing in .NET Framework.

Applies to

.NET 10 and other versions

Product	Versions
.NET	Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10
.NET Framework	2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard	2.0, 2.1

Share via

WebClient.OpenWrite Method

Definition

Overloads

OpenWrite(String)

Parameters

Returns

Exceptions

Examples

Remarks

Applies to

OpenWrite(Uri)

Parameters

Returns

Exceptions

Remarks

Applies to

OpenWrite(String, String)

Parameters

Returns

Exceptions

Examples

Remarks

Applies to

OpenWrite(Uri, String)

Parameters

Returns

Exceptions

Remarks

Applies to

Additional resources