HttpWebRequest.AllowWriteStreamBuffering Proprietà

Definizione

Spazio dei nomi:

System.Net

Assembly:

System.Net.Requests.dll

Origine:

HttpWebRequest.cs

Ottiene o imposta un valore che indica se memorizzare nel buffer i dati inviati alla risorsa Internet.

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

Valore della proprietà

Boolean

true per abilitare il buffer dei dati inviati alla risorsa Internet; false per disabilitare il buffering. Il valore predefinito è true.

Esempio

Nell'esempio di codice seguente viene utilizzata la proprietà AllowWriteStreamBuffering per disabilitare il buffer dei dati.

// 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)

Commenti

Cautela

WebRequest, HttpWebRequest, ServicePointe WebClient sono obsoleti e non è consigliabile usarli per nuovi sviluppi. Usare invece HttpClient.

Quando AllowWriteStreamBuffering è true, i dati vengono memorizzati nel buffer in memoria in modo che siano pronti per essere reinviati in caso di reindirizzamenti o richieste di autenticazione.

Note per gli eredi

L'impostazione di AllowWriteStreamBuffering su true potrebbe causare problemi di prestazioni durante il caricamento di set di dati di grandi dimensioni perché il buffer di dati potrebbe usare tutta la memoria disponibile.