HttpWebRequest.AllowWriteStreamBuffering Propriedade

Definição

Namespace:

System.Net

Assembly:

System.Net.Requests.dll

Origem:

HttpWebRequest.cs

Obtém ou define um valor que indica se os dados enviados para o recurso da Internet devem ser armazenados em buffer.

public:
 virtual property bool AllowWriteStreamBuffering { bool get(); void set(bool value); };

public virtual bool AllowWriteStreamBuffering { get; set; }

member this.AllowWriteStreamBuffering : bool with get, set

Public Overridable Property AllowWriteStreamBuffering As Boolean

Valor da propriedade

Boolean

true para habilitar o buffer dos dados enviados para o recurso da Internet; false desabilitar o buffer. O padrão é true.

Exemplos

O exemplo de código a seguir usa a propriedade AllowWriteStreamBuffering para desabilitar o buffer de dados.

// Create a new 'HttpWebRequest' object to the mentioned Uri.
HttpWebRequest^ myHttpWebRequest = (HttpWebRequest^)( WebRequest::Create( "http://www.contoso.com/codesnippets/next.asp" ) );
// Set AllowWriteStreamBuffering to 'false'.
myHttpWebRequest->AllowWriteStreamBuffering = false;
Console::WriteLine( "\nPlease Enter the data to be posted to the (http://www.contoso.com/codesnippets/next.asp) uri:" );
String^ inputData = Console::ReadLine();
String^ postData = String::Concat( "firstone= ", inputData );
// Set 'Method' property of 'HttpWebRequest' class to POST.
myHttpWebRequest->Method = "POST";
ASCIIEncoding^ encodedData = gcnew ASCIIEncoding;
array<Byte>^ byteArray = encodedData->GetBytes( postData );
// Set 'ContentType' property of the 'HttpWebRequest' class to S"application/x-www-form-urlencoded".
myHttpWebRequest->ContentType = "application/x-www-form-urlencoded";
// If the AllowWriteStreamBuffering property of HttpWebRequest is set to false, the contentlength has to be set to length of data to be posted else Exception(411) is raised.
myHttpWebRequest->ContentLength = byteArray->Length;
Stream^ newStream = myHttpWebRequest->GetRequestStream();
newStream->Write( byteArray, 0, byteArray->Length );
newStream->Close();
Console::WriteLine( "\nData has been posted to the Uri\n\nPlease wait for the response.........." );
// Assign the response object of 'HttpWebRequest' to a 'HttpWebResponse' variable.
HttpWebResponse^ myHttpWebResponse = (HttpWebResponse^)( myHttpWebRequest->GetResponse() );

// Create a new 'HttpWebRequest' object to the mentioned Uri.				
HttpWebRequest myHttpWebRequest=(HttpWebRequest)WebRequest.Create("http://www.contoso.com/codesnippets/next.asp");
// Set AllowWriteStreamBuffering to 'false'.
myHttpWebRequest.AllowWriteStreamBuffering=false;
Console.WriteLine("\nPlease Enter the data to be posted to the (http://www.contoso.com/codesnippets/next.asp) uri:");
string inputData =Console.ReadLine();
string postData="firstone="+inputData;
// Set 'Method' property of 'HttpWebRequest' class to POST.
myHttpWebRequest.Method="POST";
ASCIIEncoding encodedData=new ASCIIEncoding();
byte[]  byteArray=encodedData.GetBytes(postData);
// Set 'ContentType' property of the 'HttpWebRequest' class to "application/x-www-form-urlencoded".
myHttpWebRequest.ContentType="application/x-www-form-urlencoded";
// If the AllowWriteStreamBuffering property of HttpWebRequest is set to false,the contentlength has to be set to length of data to be posted else Exception(411) is raised.
myHttpWebRequest.ContentLength=byteArray.Length;
Stream newStream=myHttpWebRequest.GetRequestStream();
newStream.Write(byteArray,0,byteArray.Length);
newStream.Close();
Console.WriteLine("\nData has been posted to the Uri\n\nPlease wait for the response..........");
// Assign the response object of 'HttpWebRequest' to a 'HttpWebResponse' variable.
HttpWebResponse myHttpWebResponse=(HttpWebResponse)myHttpWebRequest.GetResponse();

 ' A new 'HttpWebRequest' object is created 				
 Dim myHttpWebRequest As HttpWebRequest = CType(WebRequest.Create("http://www.contoso.com/codesnippets/next.asp"), HttpWebRequest)
' AllowWriteStreamBuffering is set to 'false' 
 myHttpWebRequest.AllowWriteStreamBuffering = False
 Console.WriteLine(ControlChars.Cr + "Please Enter the data to be posted to the (http://www.contoso.com/codesnippets/next.asp) uri:")
 Dim inputData As String = Console.ReadLine()
 Dim postData As String = "firstone" + ChrW(61) + inputData
 ' 'Method' property of 'HttpWebRequest' class is set to POST.
 myHttpWebRequest.Method = "POST"
 Dim encodedData As New ASCIIEncoding()
 Dim byteArray As Byte() = encodedData.GetBytes(postData)
 ' 'ContentType' property of the 'HttpWebRequest' class is set to "application/x-www-form-urlencoded".
 myHttpWebRequest.ContentType = "application/x-www-form-urlencoded"
 ' If the AllowWriteStreamBuffering property of HttpWebRequest is set to false,then contentlength has to be set to length of data to be posted else Exception(411) Length required is raised.
  myHttpWebRequest.ContentLength=byteArray.Length
 Dim newStream As Stream = myHttpWebRequest.GetRequestStream()
 newStream.Write(byteArray, 0, byteArray.Length)
 newStream.Close()
 Console.WriteLine(ControlChars.Cr + "Data has been posted to the Uri" + ControlChars.Cr + ControlChars.Cr + "Please wait for the response..........")
 ' The response object of 'HttpWebRequest' is assigned to a 'HttpWebResponse' variable.
 Dim myHttpWebResponse As HttpWebResponse = CType(myHttpWebRequest.GetResponse(), HttpWebResponse)

Comentários

Cuidado

WebRequest, HttpWebRequest, ServicePointe WebClient estão obsoletos e você não deve usá-los para um novo desenvolvimento. Em vez disso, use HttpClient.

Quando AllowWriteStreamBuffering é true, os dados são armazenados em buffer na memória para que estejam prontos para serem ressentidos no caso de redirecionamentos ou solicitações de autenticação.

Notas aos Herdeiros

Definir AllowWriteStreamBuffering para true pode causar problemas de desempenho ao carregar grandes conjuntos de dados porque o buffer de dados pode usar toda a memória disponível.