HttpWebRequest.AllowWriteStreamBuffering プロパティとは何？わかりやすく解説 Weblio辞書

.NET Framework クラスライブラリリファレンス

索引トップ用語の索引ランキング

HttpWebRequest.AllowWriteStreamBuffering プロパティ

インターネットリソースに送信するデータをバッファリングするかどうかを示す値を取得または設定します。

名前空間: System.Net
アセンブリ: System (system.dll 内)
構文

Visual Basic (宣言)

Public Property AllowWriteStreamBuffering As
 Boolean

Visual Basic (使用法)

Dim instance As HttpWebRequest
Dim value As Boolean

value = instance.AllowWriteStreamBuffering

instance.AllowWriteStreamBuffering = value

public bool AllowWriteStreamBuffering { get;
 set; }

C++

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

/** @property */
public boolean get_AllowWriteStreamBuffering ()

/** @property */
public void set_AllowWriteStreamBuffering (boolean
 value)

JScript

public function get AllowWriteStreamBuffering
 () : boolean

public function set AllowWriteStreamBuffering
 (value : boolean)

プロパティ値
インターネットリソースに送信するデータのバッファリングを有効にする場合は true。バッファリングを無効にする場合は false。既定値は true です。

解説

AllowWriteStreamBuffering が true の場合、データはメモリにバッファリングされるため、リダイレクト要求または認証要求が発生したときにすぐに再送信できます。

実装時の注意 AllowWriteStreamBuffering を true に設定すると、大きなデータセットをアップロードするときに、パフォーマンス上の問題が生じることがあります。これは、データバッファが、利用できるメモリをすべて使用してしまう可能性があるためです。

Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows CE プラットフォームメモ : パフォーマンス上の理由から、このプロパティの既定値は false です。ただし、動詞に POST などのエンティティデータが必要な場合は、リダイレクトと認証が行われない場合があることに注意してください。HTTP 要求に対する .NET Framework の機能を完全に実装するには、AllowWriteStreamBuffering を true に設定します。

使用例

AllowWriteStreamBuffering プロパティを使用して、データバッファリングを無効にするコード例を次に示します。

Visual Basic

 ' 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)

// 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();

C++

// 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.set_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.set_Method("POST");
ASCIIEncoding encodedData =  new ASCIIEncoding();
ubyte byteArray[] = encodedData.GetBytes(postData);
// Set 'ContentType' property of the 'HttpWebRequest' class to 
// "application/x-www-form-urlencoded".
myHttpWebRequest.set_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.set_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());