HttpWebRequest.AllowWriteStreamBuffering Propriedade

Definição

Recebe ou define um valor que indica se deve armazenar em buffer os dados enviados para o recurso da Internet.

public:
 property bool AllowWriteStreamBuffering { bool get(); void set(bool value); };
public:
 virtual property bool AllowWriteStreamBuffering { bool get(); void set(bool value); };
public bool AllowWriteStreamBuffering { get; set; }
public virtual bool AllowWriteStreamBuffering { get; set; }
member this.AllowWriteStreamBuffering : bool with get, set
Public Property AllowWriteStreamBuffering As Boolean
Public Overridable Property AllowWriteStreamBuffering As Boolean

Valor de Propriedade

true para permitir o buffering dos dados enviados para o recurso da Internet; false para desativar o buffering. A predefinição é true.

Exemplos

O exemplo de código seguinte utiliza esta AllowWriteStreamBuffering propriedade para desativar o buffering 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="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)

Observações

Atenção

WebRequest, HttpWebRequest, ServicePoint, e WebClient são obsoletos, e não deves usá-los para novos desenvolvimentos. Utilize HttpClient em substituição.

Quando AllowWriteStreamBuffering é true, os dados são armazenados em memória para estarem prontos para serem reenviados em caso de redirecionamentos ou pedidos de autenticação.

Notas para 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.

Aplica-se a