HttpWebRequest.Headers Properti

Definisi

Ruang nama:

System.Net

Rakitan:

System.Net.Requests.dll

Sumber:

HttpWebRequest.cs

Menentukan kumpulan pasangan nama/nilai yang membentuk header HTTP.

public:
 virtual property System::Net::WebHeaderCollection ^ Headers { System::Net::WebHeaderCollection ^ get(); void set(System::Net::WebHeaderCollection ^ value); };

public override System.Net.WebHeaderCollection Headers { get; set; }

member this.Headers : System.Net.WebHeaderCollection with get, set

Public Overrides Property Headers As WebHeaderCollection

Nilai Properti

WebHeaderCollection

WebHeaderCollection yang berisi pasangan nama/nilai yang membentuk header untuk permintaan HTTP.

Pengecualian

InvalidOperationException

Permintaan telah dimulai dengan memanggil GetRequestStream()metode , , BeginGetRequestStream(AsyncCallback, Object)GetResponse(), atau BeginGetResponse(AsyncCallback, Object) .

Contoh

Contoh kode berikut menggunakan Headers properti untuk mencetak pasangan nama/nilai header HTTP ke konsol.

// Create a new 'HttpWebRequest' Object to the mentioned URL.
HttpWebRequest^ myHttpWebRequest = (HttpWebRequest^)( WebRequest::Create( "http://www.contoso.com" ) );
// Assign the response object of 'HttpWebRequest' to a 'HttpWebResponse' variable.
HttpWebResponse^ myHttpWebResponse = (HttpWebResponse^)( myHttpWebRequest->GetResponse() );
Console::WriteLine( "\nThe HttpHeaders are \n\n\tName\t\tValue\n {0}", myHttpWebRequest->Headers );
// Print the HTML contents of the page to the console.
Stream^ streamResponse = myHttpWebResponse->GetResponseStream();
StreamReader^ streamRead = gcnew StreamReader( streamResponse );
array<Char>^ readBuff = gcnew array<Char>(256);
int count = streamRead->Read( readBuff, 0, 256 );
Console::WriteLine( "\nThe HTML contents of page the are  : \n\n " );
while ( count > 0 )
{
   String^ outputData = gcnew String( readBuff,0,count );
   Console::Write( outputData );
   count = streamRead->Read( readBuff, 0, 256 );
}
streamResponse->Close();
streamRead->Close();
// Release the HttpWebResponse Resource.
myHttpWebResponse->Close();

// Create a new 'HttpWebRequest' Object to the mentioned URL.
HttpWebRequest myHttpWebRequest=(HttpWebRequest)WebRequest.Create("http://www.contoso.com");
// Assign the response object of 'HttpWebRequest' to a 'HttpWebResponse' variable.
HttpWebResponse myHttpWebResponse=(HttpWebResponse)myHttpWebRequest.GetResponse();
Console.WriteLine("\nThe HttpHeaders are \n\n\tName\t\tValue\n{0}",myHttpWebRequest.Headers);
// Print the HTML contents of the page to the console.
Stream streamResponse=myHttpWebResponse.GetResponseStream();
StreamReader streamRead = new StreamReader( streamResponse );
Char[] readBuff = new Char[256];
int count = streamRead.Read( readBuff, 0, 256 );
Console.WriteLine("\nThe HTML contents of page the are  : \n\n ");	
while (count > 0)
{
    String outputData = new String(readBuff, 0, count);
    Console.Write(outputData);
    count = streamRead.Read(readBuff, 0, 256);
}
// Close the Stream object.
streamResponse.Close();
streamRead.Close();
// Release the HttpWebResponse Resource.
myHttpWebResponse.Close();

     ' Create a new 'HttpWebRequest' Object to the mentioned URL.
     Dim myHttpWebRequest As HttpWebRequest = CType(WebRequest.Create("http://www.contoso.com"), HttpWebRequest)
     ' Assign the response object of 'HttpWebRequest' to a 'HttpWebResponse' variable.
     Dim myHttpWebResponse As HttpWebResponse = CType(myHttpWebRequest.GetResponse(), HttpWebResponse)
     Console.WriteLine(ControlChars.Cr + "The HttpHeaders are " + ControlChars.Cr + ControlChars.Cr + ControlChars.Tab + "Name" + ControlChars.Tab + ControlChars.Tab + "Value" + ControlChars.Cr + "{0}", myHttpWebRequest.Headers)

     ' Print the HTML contents of the page to the console. 
     Dim streamResponse As Stream = myHttpWebResponse.GetResponseStream()
     Dim streamRead As New StreamReader(streamResponse)
     Dim readBuff(256) As [Char]
     Dim count As Integer = streamRead.Read(readBuff, 0, 256)
     Console.WriteLine(ControlChars.Cr + "The HTML contents of page the are  : " + ControlChars.Cr + ControlChars.Cr + " ")
     While count > 0
         Dim outputData As New [String](readBuff, 0, count)
         Console.Write(outputData)
         count = streamRead.Read(readBuff, 0, 256)
     End While
' Close the Stream object.
streamResponse.Close()
streamRead.Close()
' Release the HttpWebResponse Resource.
 myHttpWebResponse.Close()

Keterangan

Koleksi Headers berisi header protokol yang terkait dengan permintaan. Tabel berikut mencantumkan header HTTP yang tidak disimpan dalam Headers koleksi tetapi diatur oleh sistem atau diatur oleh properti atau metode.

Header	Diatur oleh
Terima	Diatur oleh Accept properti .
Koneksi	Diatur oleh Connection properti dan KeepAlive properti .
Panjang-Konten	Diatur oleh ContentLength properti .
Jenis-Konten	Diatur oleh ContentType properti .
Mengharapkan	Diatur oleh Expect properti .
Tanggal	Diatur oleh Date properti .
Host	Diatur oleh Host properti .
If-Modified-Since	Diatur oleh IfModifiedSince properti .
Rentang	Diatur oleh AddRange metode .
Referer	Diatur oleh Referer properti .
Pengodean-Transfer	Diatur oleh TransferEncoding properti ( SendChunked properti harus benar).
Agen-Pengguna	Diatur oleh UserAgent properti .

Metode ini Add melempar ArgumentException jika Anda mencoba mengatur salah satu header yang dilindungi ini.

Mengubah Headers properti setelah permintaan dimulai dengan memanggil GetRequestStreammetode , , BeginGetRequestStreamGetResponse, atau BeginGetResponse melemparkan InvalidOperationException.

Anda tidak boleh berasumsi bahwa nilai header akan tetap tidak berubah, karena server web dan cache dapat mengubah atau menambahkan header ke permintaan Web.